MySQL CREATE FUNCTION 语法
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MySQL CREATE FUNCTION Syntax
提问by Mel
I am trying to create a function in MySQL:
我正在尝试在 MySQL 中创建一个函数：
Here is the SQL code:
这是SQL代码：
CREATE FUNCTION F_Dist3D (x1 decimal, y1 decimal)
RETURNS decimal
DETERMINISTIC
BEGIN
DECLARE dist decimal;
SET dist = SQRT(x1 - y1);
RETURN dist;
END;
I am getting the following error:
我收到以下错误：
#1064 - You have an error in your SQL syntax;
check the manual that corresponds to your MySQL
server version for the right syntax to use near '' at line 10
I am running this create statement in phpMyAdmin. What is wrong with this function?
我在 phpMyAdmin 中运行这个 create 语句。这个功能有什么问题？
回答by james_bond
You have to override your ;delimiter with something like $$to avoid this kind of error.
你必须;用类似的东西覆盖你的分隔符，$$以避免这种错误。
After your function definition, you can set the delimiter back to ;.
在函数定义之后，您可以将分隔符设置回;.
This should work:
这应该有效：
DELIMITER $$
CREATE FUNCTION F_Dist3D (x1 decimal, y1 decimal)
RETURNS decimal
DETERMINISTIC
BEGIN
DECLARE dist decimal;
SET dist = SQRT(x1 - y1);
RETURN dist;
END$$
DELIMITER ;
回答by biswarupadhikari
MySQL create function syntax:
MySQL 创建函数语法：
DELIMITER //
CREATE FUNCTION GETFULLNAME(fname CHAR(250),lname CHAR(250))
RETURNS CHAR(250)
BEGIN
DECLARE fullname CHAR(250);
SET fullname=CONCAT(fname,' ',lname);
RETURN fullname;
END //
DELIMITER ;
Use This Function In Your Query
在您的查询中使用此函数
SELECT a.*,GETFULLNAME(a.fname,a.lname) FROM namedbtbl as a
SELECT GETFULLNAME("Biswarup","Adhikari") as myname;
Watch this Video how to create mysql function and how to use in your query
观看此视频，了解如何创建 mysql 函数以及如何在查询中使用
