TA貢獻2019條經驗 獲得超9個贊
SELECT * FROM test WHERE texte LIKE '%something%' LIMIT 1
mysql_num_rows()
(更快)
SELECT count(*) as count FROM test WHERE text LIKE '%something%
SELECT EXISTS(SELECT 1 FROM test WHERE text LIKE '%something%')
SELECT EXISTS(SELECT 1 FROM test WHERE text LIKE '%something%'
LIMIT 1)
SELECT * FROM test2 WHERE id ='321321' LIMIT 1
mysql_num_rows()
SELECT count(*) as count FROM test2 WHERE id ='321321'
SELECT EXISTS(SELECT 1 FROM test2 WHERE id ='321321')
SELECT EXISTS(SELECT 1 FROM test2 WHERE id ='321321' LIMIT 1)
(更快)
TA貢獻1807條經驗 獲得超9個贊
例子：
mysql> SELECT * FROM table_1;
+----+--------+
| id | col1 |
+----+--------+
| 1 | foo |
| 2 | bar |
| 3 | foobar |
+----+--------+
3 rows in set (0.00 sec)
mysql> SELECT EXISTS(SELECT 1 FROM table_1 WHERE id = 1);
+--------------------------------------------+
| EXISTS(SELECT 1 FROM table_1 WHERE id = 1) |
+--------------------------------------------+
| 1 |
+--------------------------------------------+
1 row in set (0.00 sec)
mysql> SELECT EXISTS(SELECT 1 FROM table_1 WHERE id = 9);
+--------------------------------------------+
| EXISTS(SELECT 1 FROM table_1 WHERE id = 9) |
+--------------------------------------------+
| 0 |
+--------------------------------------------+
1 row in set (0.00 sec)
使用別名：
mysql> SELECT EXISTS(SELECT 1 FROM table_1 WHERE id = 1) AS mycheck;
+---------+
| mycheck |
+---------+
| 1 |
+---------+
1 row in set (0.00 sec)
舉報