| 2 | 20 |
| 3 | 500,200 |
+------+---------------------------------------+
3 rows in set (0.00 sec)
4、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) |
+----------------+
+----------------+
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)