使用 mysql、php 和 pdo 选择不区分大小写 [英] Select case insensitive using mysql, php and pdo

问题描述

我正在尝试从 mysql 表中选择一些数据，但我无法将 Where 比较设为不区分大小写，我尝试使用 LOWER:

I'm trying to select some data from a mysql table but I cannot get the Where comparison to be case insensitive, I tried using LOWER:

$wildcard = $_GET['q'];
        $query = "SELECT id, name, departamento FROM gestionDoc_cargos WHERE (LOWER(name) LIKE '%' LOWER(:wildcard) '%' OR LOWER(departamento) LIKE '%' LOWER(:wildcard) '%')";

        try{
            $result = DB::getInstance()->prepare($query);
            $result->bindParam(':wildcard', $wildcard, PDO::PARAM_STR);
            $result->execute();
            $result = $result->fetchAll(PDO::FETCH_ASSOC);
        }catch(PDOException $e){
            die($e->getMessage());
        }
        print_r($result);
        echo json_encode(array_values($result));

但我收到以下错误:

SQLSTATE[42000]: Syntax error or access violation: 1064 You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'LOWER('C') '%' OR LOWER(departamento) LIKE '%' LOWER('C') '%')' at line 1

如果我从查询中删除 LOWER，我会得到一个区分大小写的选择.

and if I remove the LOWER from the query I get a case sensitive select.

推荐答案

这个

...snip... ) LIKE '%' LOWER(:wildcard) '%' OR ...snip

不正确.您有一个字符串 ('%') 后跟一个函数调用 (LOWER()) 后跟另一个字符串，它们只是坐在那里 - 没有连接逻辑，没有串联，等等等等.

is incorrect. You've got a string ('%') followed by a function call (LOWER()) followed by another string, and they're just sitting there - no connecting logic, no concatenation, blah blah blah .

应该是

... LIKE CONCAT('%', LOWER(:wildcard), '%') OR ...

默认情况下，mysql 比较不区分大小写，除非您强制进行 binary 比较，或者您在 db/table 上使用区分大小写的排序规则.

And by default, mysql comparisons ARE case insensitive, unless you force a binary comparison, or you're using a case sensitive collation on your db/table.

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