MySQL中如何使用LPAD()和RPAD()函数

lpad()/rpad()

lpad(str,len,padstr)

rpad(str,len,padstr)

SELECT LPAD(123, 6, '0') AS str1, LPAD(123, 2, '0') AS str2,
       RPAD(123, 6, '0') AS str1, RPAD(123, 2, '0') AS str1;
str1  |str2|str1  |str1|
------+----+------+----+
000123|12  |123000|12  |

当字符串 str 的长度大于 len 时，相当于从右侧截断字符串。

另外，

REPEAT(str,count)

SELECT REPEAT('?', 5) AS str;
str       |
----------+
?????|