mysql自定义函数怎么写？

mysql>CREATE FUNCTION HelloWorld4()

->RETURNS VARCHAR(20)

->BEGIN

->  RETURN 'Hello World!'

->END

->//

Query OK, 0 rows affected (0.00 sec)

mysql>select HelloWorld4() //

+---------------+

| HelloWorld4() |

+---------------+

| Hello World!  |

+---------------+

1 row in set (0.00 sec) ...展开mysql>CREATE FUNCTION HelloWorld4()

->RETURNS VARCHAR(20)

->BEGIN

->  RETURN 'Hello World!'

->END

->//

Query OK, 0 rows affected (0.00 sec)

mysql>select HelloWorld4() //

+---------------+

| HelloWorld4() |

+---------------+

| Hello World!  |

+---------------+

1 row in set (0.00 sec)

mysql>CREATE FUNCTION HelloWorld4()

->RETURNS VARCHAR(20)

->BEGIN

->RETURN 'Hello World!'

->END

->//

Query OK, 0 rows affected (0.00 sec)

mysql>select HelloWorld4() //

+---------------+

| HelloWorld4() |

+---------------+

| Hello World! |

+---------------+

1 row in set (0.00 sec)

如果你会其它数据库的话， 那么看看那个 SQL 存储过程编写 参考手册 对你会有些帮助。

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