工作中遇到一个问题:要更新一个数据表。
这个表是我自己创建的,有7个字段,id、name、package等等
创建的时候,因为我把name、package的信息分别存在两个文本文件中,
所以我就用Insert方法,一次性将所有的name插入数据库中。
name全部导入数据库中了,但是我的package没有导入,这时我仍然想用insert的方法插入,但是不行。
这时候应该利用update的方法。一次更新多条信息的思路如下:
UPDATE table_name SET field_name = CASE other_field WHEN 1 THEN 'value' WHEN 2 THEN 'value' WHEN 3 THEN 'value' END WHERE id IN (1,2,3)测试代码如下:<?php /* *function: insert app's apk ,logo_url, document_title,app_desc,package_name * into talbe atable use database db . */ //connect database catx. $server='localhost';
$user='root';
$passwd='root';
$port='3306';
$dbname='catx';
$link=mysql_connect($server,$user,$passwd);
if (!$link) {
die('Could not connect: ' . mysql_error());
}
else echo "Connected successfullyn";
mysql_select_db("db",$link);
//set init variable and start time $st=microtime_float();
$table="pydot_g";
$path = "txt";
$fname_package_name = "package_name.txt";
// $handle= @fopen($path."/".$fname_package_name, "r");
$i=1;
$sql = "UPDATE pydot_g SET package_name = CASE id ";
$ids="";
while(($buf[$i]=fgets($handle,512))!==false){
$sql .= sprintf("WHEN %d THEN '%s' ", $i, $buf[$i]);
// 拼接SQL语句 $ids .= sprintf("%d,",$i);
$i++;
}
//$ids=implode(',',$ids);
$ids.=$i;
$sql .= "END WHERE id IN ($ids)";
echo $sql;
mysql_query($sql);
fclose($handle);
mysql_close($link);
//echo the results and total time used $et=microtime_float();
$t=$et-$st;
echo "rninsert into talbe ",$table," ",$i,"times;
rn";
echo "Total time $t seconds.rn";
//function calculate time ,return a float number function microtime_float(){
list($usec, $sec) = explode(" ", microtime());
return ((float)$usec + (float)$sec);
}
?>