描述错了，是字段值，比如：
mysql> select * from t where name = ‘A’;
±—±-----±----+
| id | name | age |
±—±-----±----+
| 1 | a | 10 |
| 2 | A | 11 |
±—±-----±----+
2 rows in set (0.01 sec)
mysql> select * from t where name = ‘a’;
±—±-----±----+
| id | name | age |
±—±-----±----+
| 1 | a | 10 |
| 2 | A | 11 |
±—±-----±----+
2 rows in set (0.02 sec)
要变成以下结果：
mysql> select * from t where name = ‘a’;
±—±-----±----+
| id | name | age |
±—±-----±----+
| 1 | a | 10 |
±—±-----±----+
1 row in set (0.00 sec)
mysql> select * from t where name = ‘A’;
±—±-----±----+
| id | name | age |
±—±-----±----+
| 2 | A | 11 |
±—±-----±----+
1 row in set (0.01 sec)