简体中文(ZH-CN) English(EN) 繁体中文(ZH-TW) 日本語(JA) 한국어(KO) Melayu(MS) Français(FR) Deutsch(DE)
Home > php教程 > php手册 > body text

php查询数据集的几种方式（mysql

WBOY
Release： 2016-06-06 19:46:40
Original
1425 people have browsed it

php操作数据集几种方式 一、 mysql_unbuffered_query() 一边查询一边给出结果，不缓存在页面当中，适合大数据处理,使用完成后，就自动销毁数据集. 不能再使用mysql_data_set($result,count)重新定位数据集中游标的启示位置。 mysql_unbuffered_query查询的结

php操作数据集几种方式

一、        mysql_unbuffered_query()

一边查询一边给出结果，不缓存在页面当中，适合大数据处理,使用完成后，就自动销毁数据集.

  1. 不能再使用mysql_data_set($result,count)重新定位数据集中游标的启示位置。
  2. mysql_unbuffered_query查询的结果集中，类似mysql_fetch_array处理过程中，不可以使用mysql_num_rows获取结果集行数。
  3. mysql_unbuffered_query查询的结果集中，类似mysql_fetch_array处理过程完成后，可以使用mysql_num_rows获取结果集行数。
  4. 之后再次操作使用类似mysql_fetch_array的函数操作数据集，将没有数据集行数为0，将不输出。

二、        mysql_query()

查询结果出来全部放在缓存里面，实用于数据量小的方便操作。

  1. 类似mysql_fetch_array的函数在操作过程中还是操作完成后，mysql_num_rows都可以获得正确的数据行数。
  2. mysql_data_set($result,count)可以在任意位置操作数据集的下表。
  3. mysqli_free_result($result);清除内存中的查询集后，同mysql_unbuffered_query()。

demo:

列子：标红部分为关键比较代码

<span>  1</span> <span>php
</span><span>  2</span> 
<span>  3</span>  
<span>  4</span> 
<span>  5</span> <span>/*</span>
<span>  6</span> 
<span>  7</span> <span> * 连接数据库
</span><span>  8</span> 
<span>  9</span> <span> * 固定不变的量，就直接用变量例如$mysql_host,变化的量例如$this->$mysql_dbname，表示当前调用者的dbname
</span><span> 10</span> 
<span> 11</span>  <span>*/</span>
<span> 12</span> 
<span> 13</span>  
<span> 14</span> 
<span> 15</span> <span>header</span>("Content-Type:text/html;charset=utf-8"<span>);
</span><span> 16</span> 
<span> 17</span>  
<span> 18</span> 
<span> 19</span>  <span>class</span><span> DbConn{
</span><span> 20</span> 
<span> 21</span>    
<span> 22</span> 
<span> 23</span>     <span>private</span> <span>$mysql_host</span>;<span>//</span><span>连接的主机</span>
<span> 24</span> 
<span> 25</span>     <span>private</span> <span>$mysql_user</span><span>;
</span><span> 26</span> 
<span> 27</span>     <span>public</span> <span>$mysql_pwd</span><span>;
</span><span> 28</span> 
<span> 29</span>     <span>private</span> <span>$mysql_language</span>;<span>//</span><span>数据库编码语言</span>
<span> 30</span> 
<span> 31</span>     <span>private</span> <span>$mysql_conn</span>;<span>//</span><span>Mysql连接对象</span>
<span> 32</span> 
<span> 33</span>     <span>private</span> <span>$db_select</span>; <span>//</span><span>选择的数据库对象</span>
<span> 34</span> 
<span> 35</span>    
<span> 36</span> 
<span> 37</span>     <span>public</span> <span>$mysql_dbname</span>;<span>//</span><span>选择要连接的数据库</span>
<span> 38</span> 
<span> 39</span>     <span>public</span> <span>$sqlstr</span>;<span>//</span><span>sql语句</span>
<span> 40</span> 
<span> 41</span>     <span>public</span> <span>$error</span>;<span>//</span><span>错误信息提示</span>
<span> 42</span> 
<span> 43</span>    
<span> 44</span> 
<span> 45</span>     <span>function</span><span> DbConn(){
</span><span> 46</span> 
<span> 47</span>         <span>$this</span>->mysql_host ="localhost"<span>;
</span><span> 48</span> 
<span> 49</span>         <span>$this</span>->mysql_user="root"<span>;
</span><span> 50</span> 
<span> 51</span>         <span>$this</span>->mysql_pwd="sasa"<span>;
</span><span> 52</span> 
<span> 53</span>         <span>$this</span>->mysql_language="UTF8"<span>;
</span><span> 54</span> 
<span> 55</span>         <span>$this</span>->mysql_conn=<span>NULL</span><span>;
</span><span> 56</span> 
<span> 57</span>         <span>$this</span>->db_select=<span>NULL</span><span>;
</span><span> 58</span> 
<span> 59</span>         <span>$this</span>->sqlstr=""<span>;
</span><span> 60</span> 
<span> 61</span>       
<span> 62</span> 
<span> 63</span> <span>    }
</span><span> 64</span> 
<span> 65</span>    
<span> 66</span> 
<span> 67</span>     <span>//</span><span>设置错误信息</span>
<span> 68</span> 
<span> 69</span>     <span>private</span>  <span>function</span> SetError(<span>$errormsg</span><span>)
</span><span> 70</span> 
<span> 71</span> <span>    {
</span><span> 72</span> 
<span> 73</span>         <span>$this</span>->error+=""+<span>$errormsg</span><span>;
</span><span> 74</span> 
<span> 75</span> <span>    }
</span><span> 76</span> 
<span> 77</span>    
<span> 78</span> 
<span> 79</span>     <span>public</span>  <span>function</span><span> ShowError()
</span><span> 80</span> 
<span> 81</span> <span>    {
</span><span> 82</span> 
<span> 83</span>         <span>return</span> <span>$this</span>-><span>error;
</span><span> 84</span> 
<span> 85</span> <span>    }
</span><span> 86</span> 
<span> 87</span>  
<span> 88</span> 
<span> 89</span>  
<span> 90</span> 
<span> 91</span>     <span>//</span><span>连接mysql</span>
<span> 92</span> 
<span> 93</span>     <span>public</span> <span>function</span><span> Connect()
</span><span> 94</span> 
<span> 95</span> <span>    {
</span><span> 96</span> 
<span> 97</span>         <span>$this</span>->mysql_conn = <span>mysql_connect</span>(<span>$this</span>->mysql_host, <span>$this</span>->mysql_user,<span>$this</span>->mysql_pwd) or <span>die</span>("mysql连接错误"); <span>//</span><span>mysql连接</span>
<span> 98</span> 
<span> 99</span>         <span>$this</span>->SetError(<span>mysql_error</span><span>());
</span><span>100</span> 
<span>101</span>         <span>//</span><span>选择连接的数据库名</span>
<span>102</span> 
<span>103</span>         <span>$this</span>->db_select = <span>mysql_select_db</span>(<span>$this</span>-><span>mysql_dbname</span>) or <span>die</span>("数据库无权限或数据库选择错误"<span>);
</span><span>104</span> 
<span>105</span>         <span>$this</span>->SetError(<span>mysql_error</span><span>());
</span><span>106</span> 
<span>107</span>         <span>mysql_query</span>("set names 'utf8'"); <span>//</span><span>编码转化</span>
<span>108</span> 
<span>109</span> <span>    }
</span><span>110</span> 
<span>111</span>  
<span>112</span> 
<span>113</span>     <span>//</span><span>关闭连接</span>
<span>114</span> 
<span>115</span>     <span>public</span> <span>function</span><span> CloseCon()
</span><span>116</span> 
<span>117</span> <span>    {
</span><span>118</span> 
<span>119</span>         <span>mysql_close</span>(<span>$this</span>-><span>mysql_conn);
</span><span>120</span> 
<span>121</span> <span>    }
</span><span>122</span> 
<span>123</span>    
<span>124</span> 
<span>125</span>     <span>//</span><span>查询方法</span>
<span>126</span> 
<span>127</span>     <span>public</span> <span>function</span><span> SelectAll()
</span><span>128</span> 
<span>129</span> <span>    {
</span><span>130</span> 
<span>131</span>          <span>$result</span> = <span>mysql_query</span>(<span>$this</span>->sqlstr,<span>$this</span>-><span>mysql_conn);
</span><span>132</span> 
<span>133</span>         <span>if</span>(<span>$result</span><span>)
</span><span>134</span> 
<span>135</span> <span>        {
</span><span>136</span> 
<span>137</span>         <span>//</span><span> $result_row = mysqli_fetch_array($result);
</span><span>138</span> 
<span>139</span> <span>        // mysql_fetch_row() 将返回结果集中的下一行，如果没有更多行则返回 FALSE。
</span><span>140</span> 
<span>141</span> <span>        // mysql_fetch_array() 将返回结果集中的键值或者数组，如果没有更多行则返回 FALSE。</span>
<span>142</span> 
<span>143</span>             <span>while</span>(<span>$result_row</span>= <span>mysql_fetch_array</span>(<span>$result</span><span>))
</span><span>144</span> 
<span>145</span> <span>            {
</span><span>146</span> 
<span>147</span>                 <span>$userid</span>=<span>$result_row</span>["userid"<span>];
</span><span>148</span> 
<span>149</span>                 <span>$username</span>=<span>$result_row</span>["username"<span>];
</span><span>150</span> 
<span>151</span>                 <span>$userpwd</span>=<span>$result_row</span>["userpwd"<span>];
</span><span>152</span> 
<span>153</span>                 <span>$useremail</span>=<span>$result_row</span>["useremail"<span>];
</span><span>154</span> 
<span>155</span>      
<span>156</span> 
<span>157</span>                 <span>echo</span> "<tr>"<span>;
</span><span>158</span> 
<span>159</span>                 <span>echo</span> "<td>用户名id：</td>
<td><span>$userid</span></td>"<span>;
</span><span>160</span> 
<span>161</span>                 <span>echo</span> "<td>用户名：</td>
<td><span>$username</span></td>"<span>;
</span><span>162</span> 
<span>163</span>                 <span>echo</span> "<td>密码：</td>
<td><span>$userpwd</span></td>"<span>;
</span><span>164</span> 
<span>165</span>                 <span>echo</span> "<td>邮箱：</td>
<td><span>$useremail</span></td>"<span>;
</span><span>166</span> 
<span>167</span>                 <span>echo</span> "</tr>"<span>;
</span><span>168</span> 
<span>169</span>                 <span>echo</span> ""<span>;
</span><span>170</span> 
<span>171</span>                
<span>172</span> 
<span>173</span>                 <span>//</span><span>mysqli_free_result($result);清除内存中的查询集</span>
<span>174</span> 
<span>175</span> <span>            }
</span><span>176</span> 
<span>177</span> <span>        }
</span><span>178</span> 
<span>179</span> <span>    }
</span><span>180</span> 
<span>181</span>    
<span>182</span> 
<span>183</span>     <span>//</span><span>大数据查询验证两种查询数据集的区别</span>
<span>184</span> 
<span>185</span>     <span>public</span> <span>function</span><span> Select()
</span><span>186</span> 
<span>187</span> <span>    {
</span><span>188</span> 
<span>189</span>         <span>//</span><span>分别取消 mysql_unbuffered_query和mysql_query查看效果</span>
<span>190</span> 
<span>191</span>       <span>$result</span> = <span>mysql_unbuffered_query</span>(<span>$this</span>->sqlstr,  <span>$this</span>-><span>mysql_conn);
</span><span>192</span> 
<span>193</span>         <span>//</span><span>$result = mysql_query($this->sqlstr,  $this->mysql_conn);</span>
<span>194</span> 
<span>195</span>        
<span>196</span> 
<span>197</span>          <span>if</span>(<span>$result</span><span>)
</span><span>198</span> 
<span>199</span> <span>        {
</span><span>200</span> 
<span>201</span>         <span>//</span><span> $result_row = mysqli_fetch_array($result);
</span><span>202</span> 
<span>203</span> <span>        // mysql_fetch_row() 将返回结果集中的下一行，如果没有更多行则返回 FALSE。
</span><span>204</span> 
<span>205</span> <span>        // mysql_fetch_array() 将返回结果集中的键值或者数组，如果没有更多行则返回 FALSE。</span>
<span>206</span> 
<span>207</span>             <span>while</span>(<span>$result_row</span>= <span>mysql_fetch_array</span>(<span>$result</span><span>))
</span><span>208</span> 
<span>209</span> <span>            {
</span><span>210</span> 
<span>211</span>                 <span>$userid</span>=<span>$result_row</span>["userid"<span>];
</span><span>212</span> 
<span>213</span>                 <span>$username</span>=<span>$result_row</span>["username"<span>];
</span><span>214</span> 
<span>215</span>                 <span>$userpwd</span>=<span>$result_row</span>["userpwd"<span>];
</span><span>216</span> 
<span>217</span>                 <span>$useremail</span>=<span>$result_row</span>["useremail"<span>];
</span><span>218</span> 
<span>219</span>      
<span>220</span> 
<span>221</span>                 <span>echo</span> "<tr>"<span>;
</span><span>222</span> 
<span>223</span>                 <span>echo</span> "<td>用户名id：</td>
<td><span>$userid</span></td>"<span>;
</span><span>224</span> 
<span>225</span>                 <span>echo</span> "<td>用户名：</td>
<td><span>$username</span></td>"<span>;
</span><span>226</span> 
<span>227</span>                 <span>echo</span> "<td>密码：</td>
<td><span>$userpwd</span></td>"<span>;
</span><span>228</span> 
<span>229</span>                 <span>echo</span> "<td>邮箱：</td>
<td><span>$useremail</span></td>"<span>;
</span><span>230</span> 
<span>231</span>                 <span>echo</span> "</tr>"<span>;
</span><span>232</span> 
<span>233</span>                 <span>echo</span> ""<span>;
</span><span>234</span> 
<span>235</span>                 <span>echo</span> "处理过程中数据集总行数获取:"<span>;
</span><span>236</span> 
<span>237</span>                 <span>//</span><span>mysql_unbuffered_query查询的结果集中，mysql_fetch_array处理过程中，不可以使用mysql_num_rows获取结果集行数</span>
<span>238</span> 
<span>239</span>                  <span>echo</span> <span>mysql_num_rows</span>(<span>$result</span><span>);
</span><span>240</span> 
<span>241</span>                  <span>echo</span> ""<span>;
</span><span>242</span> 
<span>243</span>               
<span>244</span> 
<span>245</span> <span>            }
</span><span>246</span> 
<span>247</span>             <span>mysql_data_seek</span>(<span>$result</span>,1);<span>//</span><span>把指针指向数据集最开始
</span><span>248</span> 
<span>249</span> <span>            //mysql_unbuffered_query查询的结果集中，mysql_fetch_array处理过程完成后，可以使用mysql_num_rows获取结果集行数</span>
<span>250</span> 
<span>251</span>             <span>echo</span> "处理完成后,数据集总行数获取："<span>;
</span><span>252</span> 
<span>253</span>             <span>echo</span> <span>mysql_num_rows</span>(<span>$result</span><span>);
</span><span>254</span> 
<span>255</span>             <span>echo</span> ""<span>;
</span><span>256</span> 
<span>257</span>            
<span>258</span> 
<span>259</span>            
<span>260</span> 
<span>261</span>             <span>//</span><span>再次操作mysql_unbuffered_query查询的结果集，数据集为空不输出</span>
<span>262</span> 
<span>263</span>              <span>while</span>(<span>$result_row</span>= <span>mysql_fetch_array</span>(<span>$result</span><span>))
</span><span>264</span> 
<span>265</span> <span>            {
</span><span>266</span> 
<span>267</span>                 <span>$userid</span>=<span>$result_row</span>["userid"<span>];
</span><span>268</span> 
<span>269</span>                 <span>$username</span>=<span>$result_row</span>["username"<span>];
</span><span>270</span> 
<span>271</span>                 <span>$userpwd</span>=<span>$result_row</span>["userpwd"<span>];
</span><span>272</span> 
<span>273</span>                 <span>$useremail</span>=<span>$result_row</span>["useremail"<span>];
</span><span>274</span> 
<span>275</span>               
<span>276</span> 
<span>277</span>                 <span>echo</span> "<tr>"<span>;
</span><span>278</span> 
<span>279</span>                 <span>echo</span> "<td>用户名id：</td>
<td><span>$userid</span></td>"<span>;
</span><span>280</span> 
<span>281</span>                 <span>echo</span> "<td>用户名：</td>
<td><span>$username</span></td>"<span>;
</span><span>282</span> 
<span>283</span>                 <span>echo</span> "<td>密码：</td>
<td><span>$userpwd</span></td>"<span>;
</span><span>284</span> 
<span>285</span>                 <span>echo</span> "<td>邮箱：</td>
<td><span>$useremail</span></td>"<span>;
</span><span>286</span> 
<span>287</span>                 <span>echo</span> "</tr>"<span>;
</span><span>288</span> 
<span>289</span>                 <span>echo</span> ""<span>;
</span><span>290</span> 
<span>291</span>                
<span>292</span> 
<span>293</span>                 <span>//</span><span>mysqli_free_result($result);清除内存中的查询集</span>
<span>294</span> 
<span>295</span> <span>            }
</span><span>296</span> 
<span>297</span>              <span>echo</span> "再次处理后行数为："<span>;
</span><span>298</span> 
<span>299</span>               <span>echo</span> <span>mysql_num_rows</span>(<span>$result</span><span>);
</span><span>300</span> 
<span>301</span>                <span>mysql_free_result</span>(<span>$result</span><span>);
</span><span>302</span> 
<span>303</span>          
<span>304</span> 
<span>305</span>         }<br>306　　　　}<br>307　　　}
Copy after login

第一次写博客，希望大家多批评指正，另求php操作数据库的优秀框架，我刚从.net转为php很多不懂的，希望能得到更多的信息

Related labels：
mysql php several kinds operate number data Way Inquire
source：php.cn
Previous article：PHP字符串函数库 Next article：php的cURL库介绍
Statement of this Website
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn
Latest Articles by Author
Latest Issues
PHP arrays obtained from URL parameters do not behave as expected I have a URL parameter that contains the category ID and I want to treat it as an array li...
From 2024-04-06 22:09:02
0
1
1428
Where should I place CustomLog directive in apache I'm using php:7.2-apachedocker. I need to disable health check url login access log. Based...
From 2024-04-06 22:03:59
0
1
990
What is the format of the variables in the return value? I am a new learner of php. I found a piece of code: if($x<time()){return[false,'error']...
From 2024-04-06 21:55:20
0
1
778
Problems encountered when using opentbs to generate odt files: values ​​of the same key are displayed in the same row instead of separate columns. I'm using a library called OpenTbs to create odt using PHP, I'm using it because columns a...
From 2024-04-06 20:18:18
0
1
483
Group MySQL results by ID for looping over I have a table with flight data in mysql. I'm writing a php code that will group and displ...
From 2024-04-06 17:27:56
0
1
406
Related Topics
More>
Popular Recommendations
Popular Tutorials
More>
Related Tutorials
Popular Recommendations
Latest courses
Latest Downloads
More>
Web Effects
Website Source Code
Website Materials
Front End Template
About us Disclaimer Sitemap
php.cn：Public welfare online PHP training，Help PHP learners grow quickly！