【MySQL】查出列值为大写字母的记录

原因：

有列数据自己应为小写，可是错误写入了大写

5

You can use Ascii() function. It returns the numeric value of the leftmost character of the input string.

For lowercase first character: ASCII code of a is 97 and z is 122. So, the ASCII code of the first character should be Between 97 and 122.

SELECT word 
FROM en_dictionary 
WHERE CHAR_LENGTH(word) > 8 
  AND ASCII(word) BETWEEN 97 AND 122
ORDER BY RAND() LIMIT 10
For uppercase first character: ASCII code of A is 65 and Z is 90. So, the ASCII code of the first character should be Between 65 and 90.

SELECT word 
FROM en_dictionary 
WHERE CHAR_LENGTH(word) > 8 
  AND ASCII(word) BETWEEN 65 AND 90
ORDER BY RAND() LIMIT 10

修改

update tag_instance set tag_name = lcase(tag_name) where ASCII(tag_name) BETWEEN 65 AND 90;