Python中使用SQLAlchemy连接Mysql数据库2（多表连接操作）
mysql
python
sqlalchemy
사용
연결하다
http://blog.csdn.net/u011573853/article/details/51355113 在上面我们已经说了单表的一些操作，现在我们说一下多表的连接 from sqlalchemy import distinct from sqlalchemy.orm import aliased Astu = aliased(Stu, 'Astu' ) Acla = aliased(Cla, 'Acla'
http://blog.csdn.net/u011573853/article/details/51355113
在上面我们已经说了单表的一些操作，现在我们说一下多表的连接
<code class=" hljs python"><span class="hljs-prompt">>>> </span><span class="hljs-keyword">from</span> sqlalchemy <span class="hljs-keyword">import</span> distinct <span class="hljs-prompt">>>> </span><span class="hljs-keyword">from</span> sqlalchemy.orm <span class="hljs-keyword">import</span> aliased <span class="hljs-prompt">>>> </span>Astu = aliased(Stu,<span class="hljs-string">'Astu'</span>) <span class="hljs-prompt">>>> </span>Acla = aliased(Cla,<span class="hljs-string">'Acla'</span>) <span class="hljs-prompt">>>> </span>Agrade = aliased(Grade,<span class="hljs-string">'Agrade'</span>)</code>
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在这里先用函数aliased（）给表起一个别名以备使用
<code class=" hljs r"><span class="hljs-comment">#查询所有有成绩的学号</span> >>> query = session.query(Stu).join(Grade,Stu.id==Grade.uid).all() SELECT stu.id AS stu_id, stu.name AS stu_name FROM stu INNER JOIN grade ON stu.id = grade.uid <span class="hljs-number">2016</span>-<span class="hljs-number">05</span>-<span class="hljs-number">10</span> <span class="hljs-number">15</span>:<span class="hljs-number">02</span>:<span class="hljs-number">36</span>,<span class="hljs-number">476</span> INFO sqlalchemy.engine.base.Engine () >>> <span class="hljs-keyword">for</span> re <span class="hljs-keyword">in</span> query: <span class="hljs-keyword">...</span> print re.id <span class="hljs-keyword">...</span> <span class="hljs-number">1</span> <span class="hljs-number">2</span> <span class="hljs-number">3</span> <span class="hljs-number">4</span> <span class="hljs-number">5</span> >>> </code>
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<code class=" hljs cpp"><span class="hljs-preprocessor">#查找有成绩的同学的学号好成绩</span> >>> print session.query(Grade.uid,Grade.gre).join(Stu,Grade.uid==Stu.id).all() SELECT grade.uid AS grade_uid, grade.gre AS grade_gre FROM grade INNER JOIN stu ON grade.uid = stu.id <span class="hljs-number">2016</span>-<span class="hljs-number">05</span>-<span class="hljs-number">10</span> <span class="hljs-number">15</span>:<span class="hljs-number">15</span>:<span class="hljs-number">22</span>,<span class="hljs-number">208</span> INFO sqlalchemy.engine.base.Engine () [(<span class="hljs-number">1L</span>, <span class="hljs-number">76L</span>), (<span class="hljs-number">1L</span>, <span class="hljs-number">76L</span>), (<span class="hljs-number">2L</span>, <span class="hljs-number">66L</span>), (<span class="hljs-number">2L</span>, <span class="hljs-number">76L</span>), (<span class="hljs-number">2L</span>, <span class="hljs-number">50L</span>), (<span class="hljs-number">3L</span>, <span class="hljs-number">96L</span>), (<span class="hljs-number">3L</span>, <span class="hljs-number">76L</span>), (<span class="hljs-number">3L</span>, <span class="hljs-number">60L</span>), (<span class="hljs-number">4L</span>, <span class="hljs-number">76L</span>), (<span class="hljs-number">4L</span>, <span class="hljs-number">76L</span>), (<span class="hljs-number">4L</span>, <span class="hljs-number">76L</span>), (<span class="hljs-number">5L</span>, <span class="hljs-number">66L</span>), (<span class="hljs-number">5L</span>, <span class="hljs-number">96L</span>), (<span class="hljs-number">5L</span>, <span class="hljs-number">96L</span>)] >>> </code>
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<code class=" hljs oxygene">#查找有成绩同学的学好成绩和课程名 >>>print session.query(Grade.uid,Grade.gre,Cla.cname).<span class="hljs-keyword">join</span>(Stu,Grade.uid==Stuid).<span class="hljs-keyword">join</span>(Cla,Grade.cid==Cla.id).all() <span class="hljs-keyword">SELECT</span> grade.uid <span class="hljs-keyword">AS</span> grade_uid, grade.gre <span class="hljs-keyword">AS</span> grade_gre, cla.cname <span class="hljs-keyword">AS</span> cla_cname <span class="hljs-keyword">FROM</span> grade INNER <span class="hljs-keyword">JOIN</span> stu <span class="hljs-keyword">ON</span> grade.uid = stu.id INNER <span class="hljs-keyword">JOIN</span> cla <span class="hljs-keyword">ON</span> grade.cid = cla.id <span class="hljs-number">2016</span>-<span class="hljs-number">05</span>-<span class="hljs-number">10</span> <span class="hljs-number">15</span>:<span class="hljs-number">21</span>:<span class="hljs-number">29</span>,<span class="hljs-number">402</span> INFO sqlalchemy.engine.base.Engine () [(<span class="hljs-number">2</span>L, <span class="hljs-number">66</span>L, <span class="hljs-string">'yuwen'</span>), (<span class="hljs-number">5</span>L, <span class="hljs-number">66</span>L, <span class="hljs-string">'yuwen'</span>), (<span class="hljs-number">3</span>L, <span class="hljs-number">96</span>L, <span class="hljs-string">'shuxue'</span>), (<span class="hljs-number">2</span>L, <span class="hljs-number">50</span>L, <span class="hljs-string">'yingyu'</span>), (<span class="hljs-number">3</span>L, <span class="hljs-number">60</span>L, <span class="hljs-string">'yingyu'</span>), (<span class="hljs-number">4</span>L, <span class="hljs-number">76</span>L, <span class="hljs-string">'yingyu'</span>), (<span class="hljs-number">5</span>L, <span class="hljs-number">96</span>L, <span class="hljs-string">'yingyu'</span>), (<span class="hljs-number">1</span>L, <span class="hljs-number">76</span>L, <span class="hljs-string">'wuli'</span>), (<span class="hljs-number">3</span>L, <span class="hljs-number">76</span>L, <span class="hljs-string">'wuli'</span>), (<span class="hljs-number">4</span>L, <span class="hljs-number">76</span>L, <span class="hljs-string">'wuli'</span>), (<span class="hljs-number">1</span>L, <span class="hljs-number">76</span>L, <span class="hljs-string">'huaxue'</span>), (<span class="hljs-number">2</span>L, <span class="hljs-number">76</span>L, <span class="hljs-string">'huaxue'</span>), (<span class="hljs-number">4</span>L, <span class="hljs-number">76</span>L, <span class="hljs-string">'huaxue'</span>), (<span class="hljs-number">5</span>L, <span class="hljs-number">96</span>L, <span class="hljs-string">'huaxue'</span>)] >>> </code>
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<code class=" hljs oxygene">#查找有成绩同学的学好成绩和课程名，并进行排序 >>> print session.query(Grade.uid,Grade.gre,Cla.cname).<span class="hljs-keyword">join</span>(Stu,Grade.uid==Stud).<span class="hljs-keyword">join</span>(Cla,Grade.cid==Cla.id).order_by(Grade.uid,Grade.gre.<span class="hljs-keyword">desc</span>()).all() <span class="hljs-keyword">SELECT</span> grade.uid <span class="hljs-keyword">AS</span> grade_uid, grade.gre <span class="hljs-keyword">AS</span> grade_gre, cla.cname <span class="hljs-keyword">AS</span> cla_cname <span class="hljs-keyword">FROM</span> grade INNER <span class="hljs-keyword">JOIN</span> stu <span class="hljs-keyword">ON</span> grade.uid = stu.id INNER <span class="hljs-keyword">JOIN</span> cla <span class="hljs-keyword">ON</span> grade.cid = cla.id <span class="hljs-keyword">ORDER</span> <span class="hljs-keyword">BY</span> grade.uid, grade.gre <span class="hljs-keyword">DESC</span> <span class="hljs-number">2016</span>-<span class="hljs-number">05</span>-<span class="hljs-number">10</span> <span class="hljs-number">15</span>:<span class="hljs-number">34</span>:<span class="hljs-number">17</span>,<span class="hljs-number">902</span> INFO sqlalchemy.engine.base.Engine () [(<span class="hljs-number">1</span>L, <span class="hljs-number">76</span>L, <span class="hljs-string">'wuli'</span>), (<span class="hljs-number">1</span>L, <span class="hljs-number">76</span>L, <span class="hljs-string">'huaxue'</span>), (<span class="hljs-number">2</span>L, <span class="hljs-number">76</span>L, <span class="hljs-string">'huaxue'</span>), (<span class="hljs-number">2</span>L, <span class="hljs-number">66</span>L, <span class="hljs-string">'yuwen'</span>), (<span class="hljs-number">2</span>L, <span class="hljs-number">50</span>L, <span class="hljs-string">'yingyu'</span>), (<span class="hljs-number">3</span>L, <span class="hljs-number">96</span>L, <span class="hljs-string">'shuxue'</span>), (<span class="hljs-number">3</span>L, <span class="hljs-number">76</span>L, <span class="hljs-string">'wuli'</span>), (<span class="hljs-number">3</span>L, <span class="hljs-number">60</span>L, <span class="hljs-string">'yingyu'</span>), (<span class="hljs-number">4</span>L, <span class="hljs-number">76</span>L, <span class="hljs-string">'yingyu'</span>), (<span class="hljs-number">4</span>L, <span class="hljs-number">76</span>L, <span class="hljs-string">'huaxue'</span>), (<span class="hljs-number">4</span>L, <span class="hljs-number">76</span>L, <span class="hljs-string">'wuli'</span>), (<span class="hljs-number">5</span>L, <span class="hljs-number">96</span>L, <span class="hljs-string">'yingyu'</span>), (<span class="hljs-number">5</span>L, <span class="hljs-number">96</span>L, <span class="hljs-string">'huaxue'</span>), (<span class="hljs-number">5</span>L, <span class="hljs-number">66</span>L, <span class="hljs-string">'yuwen'</span>)] >>> </code>
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或
<code class=" hljs avrasm">>>> query2=session<span class="hljs-preprocessor">.query</span>(Grade<span class="hljs-preprocessor">.uid</span>,Grade<span class="hljs-preprocessor">.gre</span>,Cla<span class="hljs-preprocessor">.cname</span>)<span class="hljs-preprocessor">.join</span>(Stu,Grade<span class="hljs-preprocessor">.uid</span>==Stid)<span class="hljs-preprocessor">.join</span>(Cla,Grade<span class="hljs-preprocessor">.cid</span>==Cla<span class="hljs-preprocessor">.id</span>)<span class="hljs-preprocessor">.order</span>_by(Grade<span class="hljs-preprocessor">.uid</span>,Grade<span class="hljs-preprocessor">.gre</span><span class="hljs-preprocessor">.desc</span>())<span class="hljs-preprocessor">.all</span>() SELECT grade<span class="hljs-preprocessor">.uid</span> AS grade_uid, grade<span class="hljs-preprocessor">.gre</span> AS grade_gre, cla<span class="hljs-preprocessor">.cname</span> AS cla_cname FROM grade INNER JOIN stu ON grade<span class="hljs-preprocessor">.uid</span> = stu<span class="hljs-preprocessor">.id</span> INNER JOIN cla ON grade<span class="hljs-preprocessor">.cid</span> = cla<span class="hljs-preprocessor">.id</span> ORDER BY grade<span class="hljs-preprocessor">.uid</span>, grade<span class="hljs-preprocessor">.gre</span> DESC <span class="hljs-number">2016</span>-<span class="hljs-number">05</span>-<span class="hljs-number">10</span> <span class="hljs-number">15</span>:<span class="hljs-number">37</span>:<span class="hljs-number">33</span>,<span class="hljs-number">628</span> INFO sqlalchemy<span class="hljs-preprocessor">.engine</span><span class="hljs-preprocessor">.base</span><span class="hljs-preprocessor">.Engine</span> () >>> for re <span class="hljs-keyword">in</span> query2: ... print re<span class="hljs-preprocessor">.uid</span>,re<span class="hljs-preprocessor">.gre</span>,re<span class="hljs-preprocessor">.cname</span> ... <span class="hljs-number">1</span> <span class="hljs-number">76</span> wuli <span class="hljs-number">1</span> <span class="hljs-number">76</span> huaxue <span class="hljs-number">2</span> <span class="hljs-number">76</span> huaxue <span class="hljs-number">2</span> <span class="hljs-number">66</span> yuwen <span class="hljs-number">2</span> <span class="hljs-number">50</span> yingyu <span class="hljs-number">3</span> <span class="hljs-number">96</span> shuxue <span class="hljs-number">3</span> <span class="hljs-number">76</span> wuli <span class="hljs-number">3</span> <span class="hljs-number">60</span> yingyu <span class="hljs-number">4</span> <span class="hljs-number">76</span> yingyu <span class="hljs-number">4</span> <span class="hljs-number">76</span> huaxue <span class="hljs-number">4</span> <span class="hljs-number">76</span> wuli <span class="hljs-number">5</span> <span class="hljs-number">96</span> yingyu <span class="hljs-number">5</span> <span class="hljs-number">96</span> huaxue <span class="hljs-number">5</span> <span class="hljs-number">66</span> yuwen >>> </code>
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只需要把你要查的字段写在query()中就好了
<code class=" hljs oxygene">#查找成绩小于等于<span class="hljs-number">70</span>同学的学好成绩和课程名，并进行排序 >>>print session.query(Grade.uid,Grade.gre,Cla.cname).<span class="hljs-keyword">join</span>(Stu,Grade.uid==Stu.id).jn(Cla,Grade.cid==Cla.id).filter(Grade.gre<=<span class="hljs-number">70</span>).order_by(Grade.uid,Grade.gre.de()).all() <span class="hljs-keyword">SELECT</span> grade.uid <span class="hljs-keyword">AS</span> grade_uid, grade.gre <span class="hljs-keyword">AS</span> grade_gre, cla.cname <span class="hljs-keyword">AS</span> cla_cname <span class="hljs-keyword">FROM</span> grade INNER <span class="hljs-keyword">JOIN</span> stu <span class="hljs-keyword">ON</span> grade.uid = stu.id INNER <span class="hljs-keyword">JOIN</span> cla <span class="hljs-keyword">ON</span> grade.cid = cla.id <span class="hljs-keyword">WHERE</span> grade.gre <= %s <span class="hljs-keyword">ORDER</span> <span class="hljs-keyword">BY</span> grade.uid, grade.gre <span class="hljs-keyword">DESC</span> <span class="hljs-number">2016</span>-<span class="hljs-number">05</span>-<span class="hljs-number">10</span> <span class="hljs-number">15</span>:<span class="hljs-number">42</span>:<span class="hljs-number">06</span>,<span class="hljs-number">742</span> INFO sqlalchemy.engine.base.Engine (<span class="hljs-number">70</span>,) [(<span class="hljs-number">2</span>L, <span class="hljs-number">66</span>L, <span class="hljs-string">'yuwen'</span>), (<span class="hljs-number">2</span>L, <span class="hljs-number">50</span>L, <span class="hljs-string">'yingyu'</span>), (<span class="hljs-number">3</span>L, <span class="hljs-number">60</span>L, <span class="hljs-string">'yingyu'</span>), (<span class="hljs-number">5</span>L, <span class="hljs-number">66</span>L, <span class="hljs-string">'yuwen'</span>)] >>> </code>
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或
<code class=" hljs r"><span class="hljs-comment">#用SQL语言来查询</span> >>> query = session.execute(<span class="hljs-string">"select uid from grade where cid = (select id fromla where cname='yuwen')"</span>) select uid from grade where cid = (select id from cla where cname=<span class="hljs-string">'yuwen'</span>) <span class="hljs-number">2016</span>-<span class="hljs-number">05</span>-<span class="hljs-number">10</span> <span class="hljs-number">17</span>:<span class="hljs-number">12</span>:<span class="hljs-number">57</span>,<span class="hljs-number">395</span> INFO sqlalchemy.engine.base.Engine () >>> <span class="hljs-keyword">for</span> re <span class="hljs-keyword">in</span> query: <span class="hljs-keyword">...</span> print re.uid <span class="hljs-keyword">...</span> <span class="hljs-number">2</span> <span class="hljs-number">5</span> >>> </code>
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<code class=" hljs avrasm"><span class="hljs-preprocessor">#把学好为2成绩为100的学生成绩改为99</span>
>>> query5 = session<span class="hljs-preprocessor">.query</span>(Grade)
>>> query5<span class="hljs-preprocessor">.filter</span>(Grade<span class="hljs-preprocessor">.uid</span>==<span class="hljs-number">2</span>,Grade<span class="hljs-preprocessor">.gre</span>==<span class="hljs-number">100</span>)<span class="hljs-preprocessor">.update</span>({Grade<span class="hljs-preprocessor">.gre</span>:<span class="hljs-number">99</span>})
<span class="hljs-number">2016</span>-<span class="hljs-number">05</span>-<span class="hljs-number">10</span> <span class="hljs-number">16</span>:<span class="hljs-number">28</span>:<span class="hljs-number">46</span>,<span class="hljs-number">485</span> INFO sqlalchemy<span class="hljs-preprocessor">.engine</span><span class="hljs-preprocessor">.base</span><span class="hljs-preprocessor">.Engine</span> UPDATE grade <span class="hljs-keyword">SET</span> gre=%s WHERE grade<span class="hljs-preprocessor">.uid</span> = %s <span class="hljs-keyword">AND</span> grade<span class="hljs-preprocessor">.gre</span> = %s
<span class="hljs-number">2016</span>-<span class="hljs-number">05</span>-<span class="hljs-number">10</span> <span class="hljs-number">16</span>:<span class="hljs-number">28</span>:<span class="hljs-number">46</span>,<span class="hljs-number">486</span> INFO sqlalchemy<span class="hljs-preprocessor">.engine</span><span class="hljs-preprocessor">.base</span><span class="hljs-preprocessor">.Engine</span> (<span class="hljs-number">99</span>, <span class="hljs-number">2</span>, <span class="hljs-number">100</span>)
<span class="hljs-number">1</span>L</code>로그인 후 복사
此时没有提交还没有正在的改变
<code class=" hljs asciidoc"><span class="hljs-header">mysql> select * from grade where gre=100;
+----+------+------+------+</span>
<span class="hljs-header">| id | uid | cid | gre |
+----+------+------+------+</span>
<span class="hljs-header">| 15 | 2 | 3 | 100 |
+----+------+------+------+</span>
1 row in set (0.00 sec)
>>> session.commit()
mysql> select * from grade where gre=100;
Empty set (0.00 sec)
也可以这样搞
>>> session.query(Grade).filter(Grade.gre==99).update({Grade.gre:50})
</code>로그인 후 복사
update里面使用的是字典类型
或这样搞
<code class=" hljs asciidoc">#用SQL语句把学语文的成绩都改为110
>>> session.execute("update grade set gre=110 where cid = (select id from cla ere cname=<span class="hljs-emphasis">'yuwen'</span>)")
<span class="hljs-code"> update grade set gre=110 where cid = (select id from cla where cname='yuwen')</span>
2016-05-10 17:15:59,383 INFO sqlalchemy.engine.base.Engine ()
<sqlalchemy.engine.result.ResultProxy object at 0xb5c895cc>
<span class="hljs-header">mysql> select * from grade where cid =(select id from cla where cname='yuwen');
+----+------+------+------+</span>
<span class="hljs-header">| id | uid | cid | gre |
+----+------+------+------+</span>
| 2 | 2 | 1 | 66 |
<span class="hljs-header">| 3 | 5 | 1 | 66 |
+----+------+------+------+</span>
2 rows in set (0.00 sec)
#提交后
>>> session.commit()
2016-05-10 17:16:18,223 INFO sqlalchemy.engine.base.Engine COMMIT
>>>
<span class="hljs-header">mysql> select * from grade where cid =(select id from cla where cname='yuwen');
+----+------+------+------+</span>
<span class="hljs-header">| id | uid | cid | gre |
+----+------+------+------+</span>
| 2 | 2 | 1 | 110 |
<span class="hljs-header">| 3 | 5 | 1 | 110 |
+----+------+------+------+</span>
2 rows in set (0.00 sec)</code>로그인 후 복사
<code class=" hljs avrasm"><span class="hljs-preprocessor">#删除成绩为50的成绩记录</span> >>> session<span class="hljs-preprocessor">.query</span>(Grade)<span class="hljs-preprocessor">.filter</span>(Grade<span class="hljs-preprocessor">.gre</span>==<span class="hljs-number">50</span>)<span class="hljs-preprocessor">.delete</span>()</code>
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<code class=" hljs asciidoc">#删除选修英语的所有成绩记录，用SQL进行 >>> session.execute( "delete from grade where cid =(select id from cla where cme=<span class="hljs-emphasis">'yingyu'</span>)") 2016-05-10 16:55:55,472 INFO sqlalchemy.engine.base.Engine delete from grade where cid =(select id from cla where cname=<span class="hljs-emphasis">'yingyu'</span>) 2016-05-10 16:55:55,472 INFO sqlalchemy.engine.base.Engine () mysql> select * from grade where cid = (select id from cla where cname=<span class="hljs-emphasis">'yingyu'</span>) <span class="hljs-header"> -> ; +----+------+------+------+</span> <span class="hljs-header">| id | uid | cid | gre | +----+------+------+------+</span> | 5 | 5 | 3 | 96 | | 9 | 4 | 3 | 76 | <span class="hljs-header">| 14 | 3 | 3 | 60 | +----+------+------+------+</span> 3 rows in set (0.00 sec) >>> session.commit() 2016-05-10 16:56:33,075 INFO sqlalchemy.engine.base.Engine COMMIT >>> mysql> select * from grade where cid = (select id from cla where cname=<span class="hljs-emphasis">'yingyu'</span>) <span class="hljs-code"> -> ;</span> Empty set (0.00 sec)</code>
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级联删除：在relationship关联时要加上passive_deletes=True外键要加上ondelete=’CASCADE’,否则sqlalchemy不能级联删除
这些是多表连接的操作
单表的操作请看http://blog.csdn.net/u011573853/article/details/51355113
一些细节会在下面进行说明（事务，加锁，编码等）
http://blog.csdn.net/u011573853/article/details/51366124
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R.E.P.O. 파일 저장 위치 : 어디에 있고 그것을 보호하는 방법은 무엇입니까?
3 몇 주 전
By DDD
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한 데이터 프레임의 전체 열을 Python의 다른 구조를 가진 다른 데이터 프레임에 효율적으로 복사하는 방법은 무엇입니까?
Apr 01, 2025 pm 11:15 PM
Python의 Pandas 라이브러리를 사용할 때는 구조가 다른 두 데이터 프레임 사이에서 전체 열을 복사하는 방법이 일반적인 문제입니다. 두 개의 dats가 있다고 가정 해
파이썬 매개 변수 주석이 문자열을 사용할 수 있습니까?
Apr 01, 2025 pm 08:39 PM
파이썬 프로그래밍에서 Python 매개 변수 주석의 대체 사용법, 매개 변수 주석은 개발자가 기능을 더 잘 이해하고 사용하는 데 도움이되는 매우 유용한 기능입니다 ...
Python 스크립트는 특정 위치에서 Cursor 위치로 출력을 어떻게 제거합니까?
Apr 01, 2025 pm 11:30 PM
Python 스크립트는 특정 위치에서 Cursor 위치로 출력을 어떻게 제거합니까? Python 스크립트를 작성할 때 이전 출력을 커서 위치로 지우는 것이 일반적입니다 ...
내 코드가 API에 의해 데이터를 반환 할 수없는 이유는 무엇입니까? 이 문제를 해결하는 방법?
Apr 01, 2025 pm 08:09 PM
내 코드가 API에 의해 데이터를 반환 할 수없는 이유는 무엇입니까? 프로그래밍에서 우리는 종종 API가 호출 될 때 NULL 값을 반환하는 문제를 겪는 경우가 종종 있습니다.
Uvicorn은 Serving_forever ()없이 HTTP 요청을 어떻게 지속적으로 듣습니까?
Apr 01, 2025 pm 10:51 PM
Uvicorn은 HTTP 요청을 어떻게 지속적으로 듣습니까? Uvicorn은 ASGI를 기반으로 한 가벼운 웹 서버입니다. 핵심 기능 중 하나는 HTTP 요청을 듣고 진행하는 것입니다 ...
Django와 MySQL을 사용하여 수십만에서 2 백만에서 2 백만 건의 데이터를 처리 할 때, 4 코어 8G 메모리 서버는 어떤 종류의 캐시 솔루션을 선택해야합니까?
Apr 01, 2025 pm 11:36 PM
Django 및 MySQL을 사용하여 Django 및 MySQL 데이터베이스를 사용할 때 큰 데이터 볼륨을 처리합니다. 데이터 볼륨이 수십만에서 2 백만에 도달하면 ...
파이썬 모래시 그래프 그리기 : 가변적 인 정의되지 않은 오류를 피하는 방법?
Apr 01, 2025 pm 06:27 PM
Python : 모래 시계 그래픽 도면 및 입력 검증을 시작 하기이 기사는 모래 시계 그래픽 드로잉 프로그램에서 Python 초보자가 발생하는 변수 정의 문제를 해결합니다. 암호...
파이썬에서 대형 제품 데이터 세트를 효율적으로 계산하고 정렬하는 방법은 무엇입니까?
Apr 01, 2025 pm 08:03 PM
데이터 변환 및 통계 : 대규모 데이터 세트의 효율적인 처리이 기사는 제품 정보가 포함 된 데이터 목록을 다른 사람으로 변환하는 방법을 자세히 소개합니다 ...
