mysql count() 函数，对结果统计计数

mysql> select * from table1 where minute(order_date)=;
+----------+------------+-----+---------------------+
| name_new | transactor | pid | order_date          |
+----------+------------+-----+---------------------+
| 3hahha   | 3xiaohong  |    | -- :: |
| 4hahha   | 4xiaohong  |    | -- :: |
| 3hahha   | bob        |    | -- :: |
| 3hahha   | lee        |    | -- :: |
+----------+------------+-----+---------------------+
 rows in set (0.00 sec)

mysql> select count(*) as num from table1 where minute(order_date)=;
+-----+
| num |
+-----+
|    |
+-----+
 row in set (0.00 sec)