缘由:
有列数据本身应为小写,但是错误写入了大写
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;