一、日期函数
mysql> select current_date();
+----------------+
| current_date() |
+----------------+
| 2026-03-09 |
+----------------+
1 row in set (0.00 sec)
mysql> select current_time();
+----------------+
| current_time() |
+----------------+
| 20:29:22 |
+----------------+
1 row in set (0.00 sec)
mysql> select current_timestamp();
+---------------------+
| current_timestamp() |
+---------------------+
| 2026-03-09 20:29:36 |
+---------------------+
1 row in set (0.00 sec)
mysql> select current_now();
ERROR 1305 (42000): FUNCTION bit_index.current_now does not exist
mysql> select now();+---------------------+
| now() |
+---------------------+
| 2026-03-09 20:29:57 |
+---------------------+
1 row in set (0.00 sec)
mysql> select date(now());
+-------------+
| date(now()) |
+-------------+
| 2026-03-09 |
+-------------+
1 row in set (0.00 sec)
二、字符串函数
mysql> select length('ABSF23afji');
+----------------------+
| length('ABSF23afji') |
+----------------------+
| 10 |
+----------------------+
1 row in set (0.00 sec)
三、数学函数
四、其他函数
