我正在使用以下查询拆分列值。它适用于不区分大小写的场景,但我希望它适用于区分大小写的场景。
例如,在字符串“Oil is a product angites are”中,如果我的搜索关键字是“angites”,则返回false
,如果搜索关键字是“angites”,则只返回true
。mysql中有什么函数允许这样做吗?
SELECT
SUBSTRING_INDEX(description, 'Ingredients', 1),
if(LOCATE('Ingredients', description)>0, SUBSTRING_INDEX(description, 'Ingredients', -1), '')
FROM `product`
最佳答案
从mysql的LOCATE函数的文档中:
此函数是多字节安全的,并且只有在
至少有一个参数是二进制字符串。
也就是说,您需要cast
/convert
参数来执行区分大小写的匹配。
例如:如果第一条记录是Oil is a product Ingredients are...
,而第二条记录是Oil is a product ingredients are...
,则以下查询:
SELECT
LOCATE('ingredients', description) AS match_both_1,
LOCATE('Ingredients', description) AS match_both_2,
LOCATE(CAST('ingredients' AS BINARY), CAST(description AS BINARY)) AS match_second,
LOCATE(CAST('Ingredients' AS BINARY), CAST(description AS BINARY)) AS match_first
FROM product
会给你预期的结果:
| match_both_1 | match_both_2 | match_second | match_first |
| 18 | 18 | 0 | 18 |
| 18 | 18 | 18 | 0 |
见DEMO。