局部变量的声明语法如下: DECLAREvariable_name datatype[DEFAULTvalue]; 1. 下面是一个声明局部变量的例子: DELIMITER//CREATEPROCEDUREexample_procedure()BEGINDECLAREmyVarINTDEFAULT0;SETmyVar=myVar+5;SELECTmyVar;END//DELIMITER; 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 在这段代码中,我们创建了一个...
SELECTmyvariable; 1. 上述代码将显示变量myvariable的值。 结论 通过上述步骤,你已经学会了如何在MySQL 8中声明变量。使用DECLARE语句声明变量,使用SET语句将值赋给变量,使用SELECT语句显示变量的值。变量在存储过程或函数中非常有用,可以存储中间计算结果、临时数据等。祝你在MySQL开发中取得成功! 引用形式的描述信息:...
The scope of a local variable is theBEGIN ... ENDblock within which it is declared. The variable can be referred to in blocks nested within the declaring block, except those blocks that declare a variable with the same name. For examples of variable declarations, seeSection 15.6.4.2, “Loc...
Error Code: 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 'DECLARE @@count int' at line 2 What do I need to do here to declare and use this variable?
DECLARE variable_name [,variable_name...] datatype [DEFAULT value]; 其中,datatype为mysql的数据类型,如:INT, FLOAT, DATE, VARCHAR(length) 例: DECLARE l_int INT unsigned default 4000000; DECLARE l_numeric NUMERIC(8,2) DEFAULT 9.95;
--declare语句专门用于定义局部变量,可以使用default来说明默认值--DECLARE 变量名 [,variable_name...] 数据类型 [DEFAULT value];declareageintdefault0;--局部变量的赋值方式一--SET 变量名 = 表达式值 [,variable_name = expression ...]setage=18;--局部变量的赋值方式二selectStuAgeintoagefromdemo.student...
1mysql> delimiter 2mysql> CREATE PROCEDUREtest.my_test(OUT aa VARCHAR(5),OUT bb INT) 3 -> BEGIN 4 -> DECLARE a VARCHAR(5); 5 -> DECLARE b INT DEFAULT 22; 6 -> SET aa = a; 7 -> SET bb = b; 8 -> END$ 9Query OK, 0 rows affected (0.07 sec) 10mysql> delimiter ; ...
declare 变量名 类型 [default 值]，如果没有写default初始值为null 变量赋值：set 变量名=值set 变量...
declare v1 INT default 0; b)、declare变量使用 声明后变量一般是在存储过程或者自定义里的,所以是写在begin和end关键字之间的,外面的不能直接定义,然后调用,所以declare也被称之为局部变量 二、session会话变量 session会话变量用的比较少,不过有个特性是和@临时变量是一致的,就是关闭会话,或者说关闭数据库连接...
Declare variable Posted by:Ratul Sen Date: January 11, 2014 04:02AM I am new to mysql development, i facing some problem on workbench, i want to declare variable but it show an 1064 error... my code --- bellow. use brainware; //database show...