Php regex: remove order by from query string

问题

I have a php method, which should remove all occurences of an "order by" mysql statement from a mysql query string.

Example 1:

STRING: SELECT * FROM table ORDER BY name

RESULT: SELECT * FROM table

Example 2:

STRING: SELECT a.* FROM (SELECT * FROM table ORDER BY name, creation_date) AS a ORDER BY a.name

Result: SELECT a.* FROM (SELECT * FROM table) AS a

My question now is: How to achive this.

I have tried the following:

if (stripos($sql, 'ORDER BY') !== false) {
    $sql = preg_replace('/\sORDER\ BY.+/i', '', $sql);
}

But this would work for example 1, but not for example 2

回答1:

Regex you can use is ORDER BY.*?(?=\s*LIMIT|\)|$).

Sample code:

$re = "/ORDER BY.*?(?=\\s*LIMIT|\\)|$)/mi"; 
$str = "SELECT * FROM table ORDER BY name\n\nSELECT a.* FROM (SELECT * FROM table ORDER BY name, created_at) AS a ORDER BY a.name\n\nSELECT t0.* FROM table t0 WHERE t0.created_at IS NOT NULL ORDER BY t0.name, t0.created_at, t0.status LIMIT 10 OFFSET 10"; 
$result = preg_replace($re, "", $str);

Demo

回答2:

ORDER BY.*?(?=\)|$)

Try this.Replace by empty space.See demo.

https://regex101.com/r/tJ2mW5/22

$re = "/ORDER BY.*?(?=\\)|$)/mi";
$str = "SELECT * FROM table ORDER BY name\nSELECT a.* FROM (SELECT * FROM table ORDER BY name, creation_date) AS a ORDER BY a.name";
$subst = "";

$result = preg_replace($re, $subst, $str);

来源：https://stackoverflow.com/questions/29231433/php-regex-remove-order-by-from-query-string

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regex