mysql的repeat()函数

用来复制字符串,如下'ab'表示要复制的字符串，2表示复制的份数

       mysql> select repeat('ab',2);
       +----------------+
       | repeat('ab',2) |
       +----------------+
       | abab           |
       +----------------+
       1 row in set (0.00 sec)
   
  

又如

       mysql> select repeat('a',2);
       +---------------+
       | repeat('a',2) |
       +---------------+
       | aa            |
       +---------------+
       1 row in set (0.00 sec)