我正在使用以下查询来拆分列值。它适用于不区分大小写的情况,但我希望它能够区分大小写。
例如,在字符串 'Oil is a product Ingredients are' 中,如果我的搜索关键字是 'ingredients',它应该返回 false
并且应该只返回 true
如果搜索关键字是“成分”。 mysql 中是否有任何函数允许这样做?
SELECT
SUBSTRING_INDEX(description, 'Ingredients', 1),
if(LOCATE('Ingredients', description)>0, SUBSTRING_INDEX(description, 'Ingredients', -1), '')
FROM `product`
最佳答案
来自mysql的文档LOCATE 功能:
This function is multibyte safe, and is case-sensitive only if at least one argument is a binary string.
也就是说,您需要cast
/convert
您的参数以执行区分大小写的匹配。
例如:如果您的第一条记录是Oil is a product Ingredients are...
,您的第二条记录是Oil is a product ingredients are.. .
然后是以下查询:
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 |
参见 DEMO .
关于mysql - 区分大小写的字符串出现,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/49371591/