mongodb高级操作(2)-查询
find
mongodb
介绍
操作
文档
查询
高级
1.查询文档find介绍 mongodb中使用find来进行查询.find的第一个参数决定了要返回哪些文档,这个参数是一个文档,用于指定查询条件.如果不指定条件默认就是{},那么就是查询所有文档. db . test . find () { _id : ObjectId ( 573c858c323f7f2e2ccb0e17 ), name
1.查询文档find介绍
mongodb中使用find来进行查询.find的第一个参数决定了要返回哪些文档,这个参数是一个文档,用于指定查询条件. 如果不指定条件默认就是{},那么就是查询所有文档.<code class="language-js" style="margin:8px 0px; font-family:Consolas,'Liberation Mono',Menlo,Courier,monospace; word-wrap:break-word"><span class="pun" style="color:rgb(147,161,161)">></span><span class="pln" style="color:rgb(72,72,76)"> db</span><span class="pun" style="color:rgb(147,161,161)">.</span><span class="pln" style="color:rgb(72,72,76)">test</span><span class="pun" style="color:rgb(147,161,161)">.</span><span class="pln" style="color:rgb(72,72,76)">find</span><span class="pun" style="color:rgb(147,161,161)">()</span></code><code class="language-js" style="margin:8px 0px; font-family:Consolas,'Liberation Mono',Menlo,Courier,monospace; word-wrap:break-word"><span class="pun" style="color:rgb(147,161,161)">{</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"_id"</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">:</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="typ" style="color:teal">ObjectId</span><span class="pun" style="color:rgb(147,161,161)">(</span><span class="str" style="color:rgb(221,17,68)">"573c858c323f7f2e2ccb0e17"</span><span class="pun" style="color:rgb(147,161,161)">),</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"name"</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">:</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"brent"</span><span class="pun" style="color:rgb(147,161,161)">,</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"age"</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">:</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="lit" style="color:rgb(25,95,145)">43</span><span class="pun" style="color:rgb(147,161,161)">,</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"status"</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">:</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"done"</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">}</span></code><code class="language-js" style="margin:8px 0px; font-family:Consolas,'Liberation Mono',Menlo,Courier,monospace; word-wrap:break-word"><span class="pun" style="color:rgb(147,161,161)">{</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"_id"</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">:</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="typ" style="color:teal">ObjectId</span><span class="pun" style="color:rgb(147,161,161)">(</span><span class="str" style="color:rgb(221,17,68)">"573c86d3017c5eb7d08aed6d"</span><span class="pun" style="color:rgb(147,161,161)">),</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"name"</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">:</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"bob"</span><span class="pun" style="color:rgb(147,161,161)">,</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"age"</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">:</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="lit" style="color:rgb(25,95,145)">1</span><span class="pun" style="color:rgb(147,161,161)">,</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"status"</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">:</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"done"</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">}</span></code><code class="language-js" style="margin:8px 0px; font-family:Consolas,'Liberation Mono',Menlo,Courier,monospace; word-wrap:break-word"><span class="pun" style="color:rgb(147,161,161)">{</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"_id"</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">:</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="typ" style="color:teal">ObjectId</span><span class="pun" style="color:rgb(147,161,161)">(</span><span class="str" style="color:rgb(221,17,68)">"573c88fe017c5eb7d08aed6e"</span><span class="pun" style="color:rgb(147,161,161)">),</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"name"</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">:</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"tom"</span><span class="pun" style="color:rgb(147,161,161)">,</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"age"</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">:</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="lit" style="color:rgb(25,95,145)">10</span><span class="pun" style="color:rgb(147,161,161)">,</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"status"</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">:</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"done"</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">}</span></code><code class="language-js" style="margin:8px 0px; font-family:Consolas,'Liberation Mono',Menlo,Courier,monospace; word-wrap:break-word"><span class="pun" style="color:rgb(147,161,161)">{</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"_id"</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">:</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="typ" style="color:teal">ObjectId</span><span class="pun" style="color:rgb(147,161,161)">(</span><span class="str" style="color:rgb(221,17,68)">"573c8bd3323f7f2e2ccb0e18"</span><span class="pun" style="color:rgb(147,161,161)">),</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"name"</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">:</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"brent"</span><span class="pun" style="color:rgb(147,161,161)">,</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"age"</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">:</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="lit" style="color:rgb(25,95,145)">30</span><span class="pun" style="color:rgb(147,161,161)">,</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"status"</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">:</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"done"</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">}</span></code>Nach dem Login kopieren
<code class="language-js" style="margin:8px 0px; font-family:Consolas,'Liberation Mono',Menlo,Courier,monospace; word-wrap:break-word"><span class="pun" style="color:rgb(147,161,161)">></span><span class="pln" style="color:rgb(72,72,76)"> db</span><span class="pun" style="color:rgb(147,161,161)">.</span><span class="pln" style="color:rgb(72,72,76)">test</span><span class="pun" style="color:rgb(147,161,161)">.</span><span class="pln" style="color:rgb(72,72,76)">find</span><span class="pun" style="color:rgb(147,161,161)">({</span><span class="str" style="color:rgb(221,17,68)">"name"</span><span class="pun" style="color:rgb(147,161,161)">:</span><span class="str" style="color:rgb(221,17,68)">"brent"</span><span class="pun" style="color:rgb(147,161,161)">})</span></code><code class="language-js" style="margin:8px 0px; font-family:Consolas,'Liberation Mono',Menlo,Courier,monospace; word-wrap:break-word"><span class="pun" style="color:rgb(147,161,161)">{</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"_id"</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">:</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="typ" style="color:teal">ObjectId</span><span class="pun" style="color:rgb(147,161,161)">(</span><span class="str" style="color:rgb(221,17,68)">"573c858c323f7f2e2ccb0e17"</span><span class="pun" style="color:rgb(147,161,161)">),</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"name"</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">:</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"brent"</span><span class="pun" style="color:rgb(147,161,161)">,</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"age"</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">:</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="lit" style="color:rgb(25,95,145)">43</span><span class="pun" style="color:rgb(147,161,161)">,</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"status"</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">:</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"done"</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">}</span></code><code class="language-js" style="margin:8px 0px; font-family:Consolas,'Liberation Mono',Menlo,Courier,monospace; word-wrap:break-word"><span class="pun" style="color:rgb(147,161,161)">{</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"_id"</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">:</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="typ" style="color:teal">ObjectId</span><span class="pun" style="color:rgb(147,161,161)">(</span><span class="str" style="color:rgb(221,17,68)">"573c8bd3323f7f2e2ccb0e18"</span><span class="pun" style="color:rgb(147,161,161)">),</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"name"</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">:</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"brent"</span><span class="pun" style="color:rgb(147,161,161)">,</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"age"</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">:</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="lit" style="color:rgb(25,95,145)">30</span><span class="pun" style="color:rgb(147,161,161)">,</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"status"</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">:</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"done"</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">}</span></code>Nach dem Login kopieren
<code class="language-js" style="margin:8px 0px; font-family:Consolas,'Liberation Mono',Menlo,Courier,monospace; word-wrap:break-word"><span class="pun" style="color:rgb(147,161,161)">></span><span class="pln" style="color:rgb(72,72,76)"> db</span><span class="pun" style="color:rgb(147,161,161)">.</span><span class="pln" style="color:rgb(72,72,76)">test</span><span class="pun" style="color:rgb(147,161,161)">.</span><span class="pln" style="color:rgb(72,72,76)">find</span><span class="pun" style="color:rgb(147,161,161)">({</span><span class="str" style="color:rgb(221,17,68)">"name"</span><span class="pun" style="color:rgb(147,161,161)">:</span><span class="str" style="color:rgb(221,17,68)">"brent"</span><span class="pun" style="color:rgb(147,161,161)">,</span><span class="str" style="color:rgb(221,17,68)">"age"</span><span class="pun" style="color:rgb(147,161,161)">:</span><span class="lit" style="color:rgb(25,95,145)">43</span><span class="pun" style="color:rgb(147,161,161)">})</span></code><code class="language-js" style="margin:8px 0px; font-family:Consolas,'Liberation Mono',Menlo,Courier,monospace; word-wrap:break-word"><span class="pun" style="color:rgb(147,161,161)">{</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"_id"</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">:</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="typ" style="color:teal">ObjectId</span><span class="pun" style="color:rgb(147,161,161)">(</span><span class="str" style="color:rgb(221,17,68)">"573c858c323f7f2e2ccb0e17"</span><span class="pun" style="color:rgb(147,161,161)">),</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"name"</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">:</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"brent"</span><span class="pun" style="color:rgb(147,161,161)">,</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"age"</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">:</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="lit" style="color:rgb(25,95,145)">43</span><span class="pun" style="color:rgb(147,161,161)">,</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"status"</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">:</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"done"</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">}</span></code>Nach dem Login kopieren
指定返回的键
有时并不是需要返回所有的键,这时可以通过指定find或者findOne的第二个参数来指定想要的键,例如只想查询"name"为"brent"的name和age键: > db.test.find({"name":"brent"},{"name":1,"age":1})<code class="language-js" style="margin:8px 0px; font-family:Consolas,'Liberation Mono',Menlo,Courier,monospace; word-wrap:break-word"><span class="pun" style="color:rgb(147,161,161)">{</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"_id"</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">:</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="typ" style="color:teal">ObjectId</span><span class="pun" style="color:rgb(147,161,161)">(</span><span class="str" style="color:rgb(221,17,68)">"573c858c323f7f2e2ccb0e17"</span><span class="pun" style="color:rgb(147,161,161)">),</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"name"</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">:</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"brent"</span><span class="pun" style="color:rgb(147,161,161)">,</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"age"</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">:</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="lit" style="color:rgb(25,95,145)">43</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">}</span></code><code class="language-js" style="margin:8px 0px; font-family:Consolas,'Liberation Mono',Menlo,Courier,monospace; word-wrap:break-word"><span class="pun" style="color:rgb(147,161,161)">{</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"_id"</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">:</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="typ" style="color:teal">ObjectId</span><span class="pun" style="color:rgb(147,161,161)">(</span><span class="str" style="color:rgb(221,17,68)">"573c8bd3323f7f2e2ccb0e18"</span><span class="pun" style="color:rgb(147,161,161)">),</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"name"</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">:</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"brent"</span><span class="pun" style="color:rgb(147,161,161)">,</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"age"</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">:</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="lit" style="color:rgb(25,95,145)">30</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">}</span></code>Nach dem Login kopieren
<span class="pun" style="color:rgb(147,161,161)">></span><span class="pln" style="color:rgb(72,72,76)"> db</span><span class="pun" style="color:rgb(147,161,161)">.</span><span class="pln" style="color:rgb(72,72,76)">test</span><span class="pun" style="color:rgb(147,161,161)">.</span><span class="pln" style="color:rgb(72,72,76)">find</span><span class="pun" style="color:rgb(147,161,161)">({</span><span class="str" style="color:rgb(221,17,68)">"name"</span><span class="pun" style="color:rgb(147,161,161)">:</span><span class="str" style="color:rgb(221,17,68)">"brent"</span><span class="pun" style="color:rgb(147,161,161)">},{</span><span class="str" style="color:rgb(221,17,68)">"<strong>status</strong>"</span><span class="pun" style="color:rgb(147,161,161)">:</span><span class="lit" style="color:rgb(25,95,145)"><strong>0</strong></span><span class="pun" style="color:rgb(147,161,161)">})</span><code class="language-js" style="margin:8px 0px; font-family:Consolas,'Liberation Mono',Menlo,Courier,monospace; word-wrap:break-word"><span class="pun" style="color:rgb(147,161,161)">{</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"_id"</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">:</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="typ" style="color:teal">ObjectId</span><span class="pun" style="color:rgb(147,161,161)">(</span><span class="str" style="color:rgb(221,17,68)">"573c858c323f7f2e2ccb0e17"</span><span class="pun" style="color:rgb(147,161,161)">),</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"name"</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">:</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"brent"</span><span class="pun" style="color:rgb(147,161,161)">,</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"age"</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">:</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="lit" style="color:rgb(25,95,145)">43</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">}</span></code><code class="language-js" style="margin:8px 0px; font-family:Consolas,'Liberation Mono',Menlo,Courier,monospace; word-wrap:break-word"><span class="pun" style="color:rgb(147,161,161)">{</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"_id"</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">:</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="typ" style="color:teal">ObjectId</span><span class="pun" style="color:rgb(147,161,161)">(</span><span class="str" style="color:rgb(221,17,68)">"573c8bd3323f7f2e2ccb0e18"</span><span class="pun" style="color:rgb(147,161,161)">),</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"name"</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">:</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"brent"</span><span class="pun" style="color:rgb(147,161,161)">,</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"age"</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">:</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="lit" style="color:rgb(25,95,145)">30</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">}</span></code>Nach dem Login kopieren
<code class="language-js" style="margin:8px 0px; font-family:Consolas,'Liberation Mono',Menlo,Courier,monospace; word-wrap:break-word"><span class="pun" style="color:rgb(147,161,161)">></span><span class="pln" style="color:rgb(72,72,76)"> db</span><span class="pun" style="color:rgb(147,161,161)">.</span><span class="pln" style="color:rgb(72,72,76)">test</span><span class="pun" style="color:rgb(147,161,161)">.</span><span class="pln" style="color:rgb(72,72,76)">find</span><span class="pun" style="color:rgb(147,161,161)">({</span><span class="str" style="color:rgb(221,17,68)">"name"</span><span class="pun" style="color:rgb(147,161,161)">:</span><span class="str" style="color:rgb(221,17,68)">"brent"</span><span class="pun" style="color:rgb(147,161,161)">},{</span><span class="str" style="color:rgb(221,17,68)">"status"</span><span class="pun" style="color:rgb(147,161,161)">:</span><span class="lit" style="color:rgb(25,95,145)">0</span><span class="pun" style="color:rgb(147,161,161)">,</span><span class="str" style="color:rgb(221,17,68)">"_id"</span><span class="pun" style="color:rgb(147,161,161)">:</span><span class="lit" style="color:rgb(25,95,145)">0</span><span class="pun" style="color:rgb(147,161,161)">})</span></code><code class="language-js" style="margin:8px 0px; font-family:Consolas,'Liberation Mono',Menlo,Courier,monospace; word-wrap:break-word"><span class="pun" style="color:rgb(147,161,161)">{</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"name"</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">:</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"brent"</span><span class="pun" style="color:rgb(147,161,161)">,</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"age"</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">:</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="lit" style="color:rgb(25,95,145)">43</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">}</span></code><code class="language-js" style="margin:8px 0px; font-family:Consolas,'Liberation Mono',Menlo,Courier,monospace; word-wrap:break-word"><span class="pun" style="color:rgb(147,161,161)">{</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"name"</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">:</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"brent"</span><span class="pun" style="color:rgb(147,161,161)">,</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"age"</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">:</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="lit" style="color:rgb(25,95,145)">30</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">}</span></code>Nach dem Login kopieren
限制
查询传递的参数必须是常量,例如如果想查询一个文档中的某两个列相等的情况是不行的.2.查询条件
查询除了上面简单介绍的精确匹配,还有更加复杂的查询,比如范围查询,or,and,取反等等查询条件
"$lt","$lte","$gt","$gte"就是全部的比较操作符.分别对应着<,<=,>和>=,可以将这些组合起来以便查找一个范围的值. 例如下面的例子查找age大于20小于30的文档:<code class="language-js" style="margin:8px 0px; font-family:Consolas,'Liberation Mono',Menlo,Courier,monospace; word-wrap:break-word"><span class="pun" style="color:rgb(147,161,161)">></span><span class="pln" style="color:rgb(72,72,76)"> db</span><span class="pun" style="color:rgb(147,161,161)">.</span><span class="pln" style="color:rgb(72,72,76)">test2</span><span class="pun" style="color:rgb(147,161,161)">.</span><span class="pln" style="color:rgb(72,72,76)">find</span><span class="pun" style="color:rgb(147,161,161)">()</span></code><code class="language-js" style="margin:8px 0px; font-family:Consolas,'Liberation Mono',Menlo,Courier,monospace; word-wrap:break-word"><span class="pun" style="color:rgb(147,161,161)">{</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"_id"</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">:</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="typ" style="color:teal">ObjectId</span><span class="pun" style="color:rgb(147,161,161)">(</span><span class="str" style="color:rgb(221,17,68)">"573e72449e178b5475b29d89"</span><span class="pun" style="color:rgb(147,161,161)">),</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"name"</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">:</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"brent"</span><span class="pun" style="color:rgb(147,161,161)">,</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"age"</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">:</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="lit" style="color:rgb(25,95,145)">28</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">}</span></code><code class="language-js" style="margin:8px 0px; font-family:Consolas,'Liberation Mono',Menlo,Courier,monospace; word-wrap:break-word"><span class="pun" style="color:rgb(147,161,161)">{</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"_id"</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">:</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="typ" style="color:teal">ObjectId</span><span class="pun" style="color:rgb(147,161,161)">(</span><span class="str" style="color:rgb(221,17,68)">"573e73149e178b5475b29d8a"</span><span class="pun" style="color:rgb(147,161,161)">),</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"name"</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">:</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"brent"</span><span class="pun" style="color:rgb(147,161,161)">,</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"age"</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">:</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="lit" style="color:rgb(25,95,145)">10</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">}</span></code><code class="language-js" style="margin:8px 0px; font-family:Consolas,'Liberation Mono',Menlo,Courier,monospace; word-wrap:break-word"><span class="pun" style="color:rgb(147,161,161)">{</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"_id"</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">:</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="typ" style="color:teal">ObjectId</span><span class="pun" style="color:rgb(147,161,161)">(</span><span class="str" style="color:rgb(221,17,68)">"573e73ae9e178b5475b29d8b"</span><span class="pun" style="color:rgb(147,161,161)">),</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"name"</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">:</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"bob"</span><span class="pun" style="color:rgb(147,161,161)">,</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"age"</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">:</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="lit" style="color:rgb(25,95,145)">14</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">}</span></code>Nach dem Login kopieren
<code class="language-js" style="margin:8px 0px; font-family:Consolas,'Liberation Mono',Menlo,Courier,monospace; word-wrap:break-word"><span class="pun" style="color:rgb(147,161,161)">></span><span class="pln" style="color:rgb(72,72,76)"> db</span><span class="pun" style="color:rgb(147,161,161)">.</span><span class="pln" style="color:rgb(72,72,76)">test2</span><span class="pun" style="color:rgb(147,161,161)">.</span><span class="pln" style="color:rgb(72,72,76)">find</span><span class="pun" style="color:rgb(147,161,161)">({</span><span class="str" style="color:rgb(221,17,68)">"age"</span><span class="pun" style="color:rgb(147,161,161)">:{</span><span class="str" style="color:rgb(221,17,68)">"$gt"</span><span class="pun" style="color:rgb(147,161,161)">:</span><span class="lit" style="color:rgb(25,95,145)">20</span><span class="pun" style="color:rgb(147,161,161)">,</span><span class="str" style="color:rgb(221,17,68)">"$lt"</span><span class="pun" style="color:rgb(147,161,161)">:</span><span class="lit" style="color:rgb(25,95,145)">30</span><span class="pun" style="color:rgb(147,161,161)">}})</span></code><code class="language-js" style="margin:8px 0px; font-family:Consolas,'Liberation Mono',Menlo,Courier,monospace; word-wrap:break-word"><span class="pun" style="color:rgb(147,161,161)">{</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"_id"</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">:</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="typ" style="color:teal">ObjectId</span><span class="pun" style="color:rgb(147,161,161)">(</span><span class="str" style="color:rgb(221,17,68)">"573e72449e178b5475b29d89"</span><span class="pun" style="color:rgb(147,161,161)">),</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"name"</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">:</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"brent"</span><span class="pun" style="color:rgb(147,161,161)">,</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"age"</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">:</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="lit" style="color:rgb(25,95,145)">28</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">}</span></code>Nach dem Login kopieren
<code class="language-js" style="margin:8px 0px; font-family:Consolas,'Liberation Mono',Menlo,Courier,monospace; word-wrap:break-word"><span class="pun" style="color:rgb(147,161,161)">></span><span class="pln" style="color:rgb(72,72,76)"> db</span><span class="pun" style="color:rgb(147,161,161)">.</span><span class="pln" style="color:rgb(72,72,76)">test2</span><span class="pun" style="color:rgb(147,161,161)">.</span><span class="pln" style="color:rgb(72,72,76)">find</span><span class="pun" style="color:rgb(147,161,161)">({</span><span class="str" style="color:rgb(221,17,68)">"name"</span><span class="pun" style="color:rgb(147,161,161)">:{</span><span class="str" style="color:rgb(221,17,68)">"$ne"</span><span class="pun" style="color:rgb(147,161,161)">:</span><span class="str" style="color:rgb(221,17,68)">"brent"</span><span class="pun" style="color:rgb(147,161,161)">}})</span></code><code class="language-js" style="margin:8px 0px; font-family:Consolas,'Liberation Mono',Menlo,Courier,monospace; word-wrap:break-word"><span class="pun" style="color:rgb(147,161,161)">{</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"_id"</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">:</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="typ" style="color:teal">ObjectId</span><span class="pun" style="color:rgb(147,161,161)">(</span><span class="str" style="color:rgb(221,17,68)">"573e73ae9e178b5475b29d8b"</span><span class="pun" style="color:rgb(147,161,161)">),</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"name"</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">:</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"bob"</span><span class="pun" style="color:rgb(147,161,161)">,</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"age"</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">:</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="lit" style="color:rgb(25,95,145)">14</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">}</span></code>Nach dem Login kopieren
OR查询
有两种方式进行OR查询:"$in"可以用来查询一个键的多个值,"$or"可以在多个键中查询任意给定的值. 例如下面要查询age为10,14的文档:<code class="language-js" style="margin:8px 0px; font-family:Consolas,'Liberation Mono',Menlo,Courier,monospace; word-wrap:break-word"><span class="pun" style="color:rgb(147,161,161)">></span><span class="pln" style="color:rgb(72,72,76)"> db</span><span class="pun" style="color:rgb(147,161,161)">.</span><span class="pln" style="color:rgb(72,72,76)">test2</span><span class="pun" style="color:rgb(147,161,161)">.</span><span class="pln" style="color:rgb(72,72,76)">find</span><span class="pun" style="color:rgb(147,161,161)">({</span><span class="str" style="color:rgb(221,17,68)">"age"</span><span class="pun" style="color:rgb(147,161,161)">:{</span><span class="str" style="color:rgb(221,17,68)">"$in"</span><span class="pun" style="color:rgb(147,161,161)">:[</span><span class="lit" style="color:rgb(25,95,145)">10</span><span class="pun" style="color:rgb(147,161,161)">,</span><span class="lit" style="color:rgb(25,95,145)">14</span><span class="pun" style="color:rgb(147,161,161)">]}})</span></code><code class="language-js" style="margin:8px 0px; font-family:Consolas,'Liberation Mono',Menlo,Courier,monospace; word-wrap:break-word"><span class="pun" style="color:rgb(147,161,161)">{</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"_id"</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">:</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="typ" style="color:teal">ObjectId</span><span class="pun" style="color:rgb(147,161,161)">(</span><span class="str" style="color:rgb(221,17,68)">"573e73149e178b5475b29d8a"</span><span class="pun" style="color:rgb(147,161,161)">),</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"name"</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">:</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"brent"</span><span class="pun" style="color:rgb(147,161,161)">,</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"age"</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">:</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="lit" style="color:rgb(25,95,145)">10</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">}</span></code><code class="language-js" style="margin:8px 0px; font-family:Consolas,'Liberation Mono',Menlo,Courier,monospace; word-wrap:break-word"><span class="pun" style="color:rgb(147,161,161)">{</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"_id"</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">:</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="typ" style="color:teal">ObjectId</span><span class="pun" style="color:rgb(147,161,161)">(</span><span class="str" style="color:rgb(221,17,68)">"573e73ae9e178b5475b29d8b"</span><span class="pun" style="color:rgb(147,161,161)">),</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"name"</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">:</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"bob"</span><span class="pun" style="color:rgb(147,161,161)">,</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"age"</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">:</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="lit" style="color:rgb(25,95,145)">14</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">}</span></code>Nach dem Login kopieren
<code class="language-js" style="margin:8px 0px; font-family:Consolas,'Liberation Mono',Menlo,Courier,monospace; word-wrap:break-word"><span class="pun" style="color:rgb(147,161,161)">></span><span class="pln" style="color:rgb(72,72,76)"> db</span><span class="pun" style="color:rgb(147,161,161)">.</span><span class="pln" style="color:rgb(72,72,76)">test2</span><span class="pun" style="color:rgb(147,161,161)">.</span><span class="pln" style="color:rgb(72,72,76)">find</span><span class="pun" style="color:rgb(147,161,161)">({</span><span class="str" style="color:rgb(221,17,68)">"age"</span><span class="pun" style="color:rgb(147,161,161)">:{</span><span class="str" style="color:rgb(221,17,68)">"$nin"</span><span class="pun" style="color:rgb(147,161,161)">:[</span><span class="lit" style="color:rgb(25,95,145)">10</span><span class="pun" style="color:rgb(147,161,161)">,</span><span class="lit" style="color:rgb(25,95,145)">14</span><span class="pun" style="color:rgb(147,161,161)">]}})</span></code><code class="language-js" style="margin:8px 0px; font-family:Consolas,'Liberation Mono',Menlo,Courier,monospace; word-wrap:break-word"><span class="pun" style="color:rgb(147,161,161)">{</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"_id"</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">:</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="typ" style="color:teal">ObjectId</span><span class="pun" style="color:rgb(147,161,161)">(</span><span class="str" style="color:rgb(221,17,68)">"573e72449e178b5475b29d89"</span><span class="pun" style="color:rgb(147,161,161)">),</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"name"</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">:</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"brent"</span><span class="pun" style="color:rgb(147,161,161)">,</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"age"</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">:</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="lit" style="color:rgb(25,95,145)">28</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">}</span></code>Nach dem Login kopieren
<code class="language-js" style="margin:8px 0px; font-family:Consolas,'Liberation Mono',Menlo,Courier,monospace; word-wrap:break-word"><span class="pun" style="color:rgb(147,161,161)">></span><span class="pln" style="color:rgb(72,72,76)"> db</span><span class="pun" style="color:rgb(147,161,161)">.</span><span class="pln" style="color:rgb(72,72,76)">test2</span><span class="pun" style="color:rgb(147,161,161)">.</span><span class="pln" style="color:rgb(72,72,76)">find</span><span class="pun" style="color:rgb(147,161,161)">({</span><span class="str" style="color:rgb(221,17,68)">"$or"</span><span class="pun" style="color:rgb(147,161,161)">:[{</span><span class="str" style="color:rgb(221,17,68)">"name"</span><span class="pun" style="color:rgb(147,161,161)">:</span><span class="str" style="color:rgb(221,17,68)">"bob"</span><span class="pun" style="color:rgb(147,161,161)">},{</span><span class="str" style="color:rgb(221,17,68)">"age"</span><span class="pun" style="color:rgb(147,161,161)">:</span><span class="lit" style="color:rgb(25,95,145)">10</span><span class="pun" style="color:rgb(147,161,161)">}]})</span></code><code class="language-js" style="margin:8px 0px; font-family:Consolas,'Liberation Mono',Menlo,Courier,monospace; word-wrap:break-word"><span class="pun" style="color:rgb(147,161,161)">{</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"_id"</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">:</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="typ" style="color:teal">ObjectId</span><span class="pun" style="color:rgb(147,161,161)">(</span><span class="str" style="color:rgb(221,17,68)">"573e73149e178b5475b29d8a"</span><span class="pun" style="color:rgb(147,161,161)">),</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"name"</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">:</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"brent"</span><span class="pun" style="color:rgb(147,161,161)">,</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"age"</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">:</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="lit" style="color:rgb(25,95,145)">10</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">}</span></code><code class="language-js" style="margin:8px 0px; font-family:Consolas,'Liberation Mono',Menlo,Courier,monospace; word-wrap:break-word"><span class="pun" style="color:rgb(147,161,161)">{</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"_id"</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">:</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="typ" style="color:teal">ObjectId</span><span class="pun" style="color:rgb(147,161,161)">(</span><span class="str" style="color:rgb(221,17,68)">"573e73ae9e178b5475b29d8b"</span><span class="pun" style="color:rgb(147,161,161)">),</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"name"</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">:</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"bob"</span><span class="pun" style="color:rgb(147,161,161)">,</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"age"</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">:</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="lit" style="color:rgb(25,95,145)">14</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">}</span></code>Nach dem Login kopieren
<code class="language-js" style="margin:8px 0px; font-family:Consolas,'Liberation Mono',Menlo,Courier,monospace; word-wrap:break-word"><span class="pun" style="color:rgb(147,161,161)">></span><span class="pln" style="color:rgb(72,72,76)"> db</span><span class="pun" style="color:rgb(147,161,161)">.</span><span class="pln" style="color:rgb(72,72,76)">test2</span><span class="pun" style="color:rgb(147,161,161)">.</span><span class="pln" style="color:rgb(72,72,76)">find</span><span class="pun" style="color:rgb(147,161,161)">({</span><span class="str" style="color:rgb(221,17,68)">"$or"</span><span class="pun" style="color:rgb(147,161,161)">:[{</span><span class="str" style="color:rgb(221,17,68)">"age"</span><span class="pun" style="color:rgb(147,161,161)">:{</span><span class="str" style="color:rgb(221,17,68)">"$in"</span><span class="pun" style="color:rgb(147,161,161)">:[</span><span class="lit" style="color:rgb(25,95,145)">10</span><span class="pun" style="color:rgb(147,161,161)">,</span><span class="lit" style="color:rgb(25,95,145)">28</span><span class="pun" style="color:rgb(147,161,161)">]}},{</span><span class="str" style="color:rgb(221,17,68)">"name"</span><span class="pun" style="color:rgb(147,161,161)">:</span><span class="str" style="color:rgb(221,17,68)">"bob"</span><span class="pun" style="color:rgb(147,161,161)">}]})</span></code><code class="language-js" style="margin:8px 0px; font-family:Consolas,'Liberation Mono',Menlo,Courier,monospace; word-wrap:break-word"><span class="pun" style="color:rgb(147,161,161)">{</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"_id"</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">:</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="typ" style="color:teal">ObjectId</span><span class="pun" style="color:rgb(147,161,161)">(</span><span class="str" style="color:rgb(221,17,68)">"573e72449e178b5475b29d89"</span><span class="pun" style="color:rgb(147,161,161)">),</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"name"</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">:</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"brent"</span><span class="pun" style="color:rgb(147,161,161)">,</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"age"</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">:</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="lit" style="color:rgb(25,95,145)">28</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">}</span></code><code class="language-js" style="margin:8px 0px; font-family:Consolas,'Liberation Mono',Menlo,Courier,monospace; word-wrap:break-word"><span class="pun" style="color:rgb(147,161,161)">{</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"_id"</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">:</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="typ" style="color:teal">ObjectId</span><span class="pun" style="color:rgb(147,161,161)">(</span><span class="str" style="color:rgb(221,17,68)">"573e73149e178b5475b29d8a"</span><span class="pun" style="color:rgb(147,161,161)">),</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"name"</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">:</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"brent"</span><span class="pun" style="color:rgb(147,161,161)">,</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"age"</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">:</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="lit" style="color:rgb(25,95,145)">10</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">}</span></code><code class="language-js" style="margin:8px 0px; font-family:Consolas,'Liberation Mono',Menlo,Courier,monospace; word-wrap:break-word"><span class="pun" style="color:rgb(147,161,161)">{</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"_id"</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">:</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="typ" style="color:teal">ObjectId</span><span class="pun" style="color:rgb(147,161,161)">(</span><span class="str" style="color:rgb(221,17,68)">"573e73ae9e178b5475b29d8b"</span><span class="pun" style="color:rgb(147,161,161)">),</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"name"</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="pun" style="color:rgb(147,161,161)">:</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"bob"</span><span class="pun" style="color:rgb(147,161,161)">,</span><span class="pln" style="color:rgb(72,72,76)"> </span><span class="str" style="color:rgb(221,17,68)">"age"</span><span class="pln" style="color:rgb(72"></span></code>Nach dem Login kopieren
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Der Unterschied zwischen NodeJS und VueJS
Apr 21, 2024 am 04:17 AM
Node.js ist eine serverseitige JavaScript-Laufzeitumgebung, während Vue.js ein clientseitiges JavaScript-Framework zum Erstellen interaktiver Benutzeroberflächen ist. Node.js wird für die serverseitige Entwicklung verwendet, beispielsweise für die Entwicklung von Back-End-Service-APIs und die Datenverarbeitung, während Vue.js für die clientseitige Entwicklung verwendet wird, beispielsweise für Single-Page-Anwendungen und reaktionsfähige Benutzeroberflächen.
Wo wird die von mongodb erstellte Datenbank erstellt?
Apr 07, 2024 pm 05:39 PM
Die Daten der MongoDB-Datenbank werden im angegebenen Datenverzeichnis gespeichert, das sich im lokalen Dateisystem, Netzwerkdateisystem oder Cloud-Speicher befinden kann. Der spezifische Speicherort ist wie folgt: Lokales Dateisystem: Der Standardpfad ist Linux/macOS: /data/db, Windows: C:\data\db. Netzwerkdateisystem: Der Pfad hängt vom Dateisystem ab. Cloud-Speicher: Der Pfad wird vom Cloud-Speicheranbieter bestimmt.
Was sind die Vorteile der Mongodb-Datenbank?
Apr 07, 2024 pm 05:21 PM
Die MongoDB-Datenbank ist für ihre Flexibilität, Skalierbarkeit und hohe Leistung bekannt. Zu seinen Vorteilen gehört: ein Dokumentdatenmodell, das eine flexible und unstrukturierte Speicherung von Daten ermöglicht. Horizontale Skalierbarkeit auf mehrere Server über Sharding. Abfrageflexibilität, Unterstützung komplexer Abfragen und Aggregationsvorgänge. Datenreplikation und Fehlertoleranz sorgen für Datenredundanz und hohe Verfügbarkeit. JSON-Unterstützung für einfache Integration mit Front-End-Anwendungen. Hohe Leistung für schnelle Reaktion auch bei der Verarbeitung großer Datenmengen. Open Source, anpassbar und kostenlos nutzbar.
Was bedeutet Mongodb?
Apr 07, 2024 pm 05:57 PM
MongoDB ist ein dokumentenorientiertes, verteiltes Datenbanksystem zur Speicherung und Verwaltung großer Mengen strukturierter und unstrukturierter Daten. Zu den Kernkonzepten gehören die Speicherung und Verteilung von Dokumenten und zu den Hauptfunktionen gehören dynamische Schemata, Indizierung, Aggregation, Kartenreduzierung und Replikation. Es wird häufig in Content-Management-Systemen, E-Commerce-Plattformen, Social-Media-Websites, IoT-Anwendungen und der Entwicklung mobiler Anwendungen eingesetzt.
So öffnen Sie Mongodb
Apr 07, 2024 pm 06:15 PM
Unter Linux/macOS: Erstellen Sie das Datenverzeichnis und starten Sie den Dienst „mongod“. Unter Windows: Erstellen Sie das Datenverzeichnis und starten Sie den MongoDB-Dienst über den Service Manager. In Docker: Führen Sie den Befehl „docker run“ aus. Auf anderen Plattformen: Bitte konsultieren Sie die MongoDB-Dokumentation. Überprüfungsmethode: Führen Sie den Befehl „mongo“ aus, um eine Verbindung herzustellen und die Serverversion anzuzeigen.
Wo sind die Mongodb-Datenbankdateien?
Apr 07, 2024 pm 05:42 PM
Die MongoDB-Datenbankdatei befindet sich im MongoDB-Datenverzeichnis, das standardmäßig /data/db ist und .bson (Dokumentdaten), ns (Sammlungsinformationen), Journal (Schreibvorgangsdatensätze) und wiredTiger (Daten bei Verwendung von WiredTiger) enthält Speicher-Engine) und config (Datenbankkonfigurationsinformationen) und andere Dateien.
Detaillierte Einführung in die Funktionen des Samsung S24ai
Jun 24, 2024 am 11:18 AM
2024 ist das erste Jahr der KI-Mobiltelefone. Dank der intelligenten KI-Technologie können unsere Mobiltelefone effizienter und bequemer genutzt werden. Kürzlich hat die zu Beginn des Jahres erschienene Galaxy S24-Serie ihr generatives KI-Erlebnis noch einmal verbessert. Werfen wir einen Blick auf die detaillierte Funktionseinführung unten. 1. Umfassende Stärkung der generativen KI. Die Samsung Galaxy S24-Serie hat durch die Stärkung der Galaxy AI viele intelligente Anwendungen hervorgebracht. Diese Funktionen sind tief in Samsung One UI6.1 integriert, sodass Benutzer jederzeit ein komfortables intelligentes Erlebnis erhalten Verbesserung der Leistung von Mobiltelefonen. Zu den Highlights der Galaxy S24-Serie gehört die Sofortsuchfunktion, die Nutzer einfach gedrückt halten müssen
