具有多个查询的 php/mysql [英] php/mysql with multiple queries

问题描述

<?php

$query1 = "CREATE VIEW current_rankings AS SELECT * FROM main_table WHERE date = X";

$query2 = "CREATE VIEW previous_rankings AS SELECT rank FROM main_table WHERE date = date_sub('X', INTERVAL 1 MONTH)";

$query3 = "CREATE VIEW final_output AS SELECT current_rankings.player, current_rankings.rank as current_rank LEFT JOIN previous_rankings.rank as prev_rank
             ON (current_rankings.player = previous_rankings.player)";

$query4 = "SELECT *, @rank_change = prev_rank - current_rank as rank_change from final_output";

$result = mysql_query($query4) or die(mysql_error()); 

while($row = mysql_fetch_array($result)) {
echo $row['player']. $row['current_rank']. $row['prev_rank']. $row['rank_change'];
}

?>

所有查询都独立工作，但我真的很难将所有部分放在一个结果中，以便我可以将它与 mysql_fetch_array 一起使用.

All the queries work independently but am really struggling putting all the pieces together in one single result so I can use it with mysql_fetch_array.

我尝试创建视图和临时表，但每次它要么说表不存在，要么返回一个空的获取数组循环......逻辑存在但语法混乱，我认为这是第一次我不得不处理需要合并在一起的多个查询.期待一些支持.非常感谢.

I've tried to create views as well as temporary tables but each time it either says table does not exist or return an empty fetch array loop...logic is there but syntax is messed up I think as it's the 1st time I had to deal with multiple queries I need to merge all together. Looking forward to some support. Many thanks.

推荐答案

感谢 php.net 我想出了一个解决方案:你必须使用 (mysqli_multi_query($link, $query))运行多个串联查询.

Thanks to php.net I've come up with a solution : you have to use (mysqli_multi_query($link, $query)) to run multiple concatenated queries.

 /* create sql connection*/
$link = mysqli_connect("server", "user", "password", "database");

$query = "SQL STATEMENTS;"; /*  first query : Notice the 2 semicolons at the end ! */
$query .= "SQL STATEMENTS;"; /* Notice the dot before = and the 2 semicolons at the end ! */
$query .= "SQL STATEMENTS;"; /* Notice the dot before = and the 2 semicolons at the end ! */
$query .= "SQL STATEMENTS"; /* last query : Notice the dot before = at the end ! */

/* Execute queries */

if (mysqli_multi_query($link, $query)) {
do {
    /* store first result set */
    if ($result = mysqli_store_result($link)) {
        while ($row = mysqli_fetch_array($result)) 

/* print your results */    
{
echo $row['column1'];
echo $row['column2'];
}
mysqli_free_result($result);
}   
} while (mysqli_next_result($link));
}

编辑 - 如果您确实想要执行一个大查询，则上述解决方案有效，但也可以执行任意数量的查询并分别执行.

EDIT - The solution above works if you really want to do one big query but it's also possible to execute as many queries as you wish and execute them separately.

$query1 = "Create temporary table A select c1 from t1"; 
$result1 = mysqli_query($link, $query1) or die(mysqli_error());

$query2 = "select c1 from A"; 
$result2 = mysqli_query($link, $query2) or die(mysqli_error());

while($row = mysqli_fetch_array($result2)) {

echo $row['c1'];
    }  

这篇关于具有多个查询的 php/mysql的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！