在sql语句中加入�变量。 declare @local_variable data_type 声明时须要指定变量的类型, 能够使用set和select对变量进行赋值, 在sql语句中就能够使用@local_variable来调用变量 声明中能够提供值,否则声明之后全部变量将初始化为NULL。 比如:declare @id int declare @id int = 3 set @id=2 select id select ...
DECLARE @Variable1 AS int, @Variable2 AS int /* 使用 SELECT */ SELECT @Variable1 = 1 /* 使用 SET */ SET @Variable2 = 2 select f1 into v1 from tab1 select f1,f2,f3 into v1,v2,v3 from tab1 说明: 1.SELECT可以在一条语句里对多个变量同时赋值,而SET只能一次对一个变量赋值 SELECT ...
本文翻译自:How to declare a variable inMySQL?How to declare a variable inmysql, so that my second query can use it? 如何在mysql中声明变量,以便第二个查询可以使用它?I would like to write something like: 我想写一些像:SET start = 1; ...
-- 运行完整的示例DECLARE@CityNVARCHAR(100);SET@City='Shanghai';SELECT*FROMCustomersWHERECity=@City; 1. 2. 3. 4. 5. 6. 状态图 接下来,我们用状态图示意整个使用局部变量定义查询条件的流程。使用mermaid语法中的 stateDiagram 来展示: Declare_VariableSet_ValueUse_Variable_In_QueryExecute_Query 总结 ...
(4)Example of CALL调用的例子mysql> CALL p10() //+---+| s1 * a |+---+| 25 || 25 |+---+2 rows in set (0.00 sec)Query OK, 0 rows affected (0.00 sec)结果显示了过程能正常工作(5) Scope作用域CREATE PROCEDURE p11 ()BEGINDECLARE x1 CHAR(5) DEFAULT 'outer';BEGIN...
-- Create a variable with a default > DECLARE VARIABLE myvar INT DEFAULT 5; > VALUES (myvar); 5 -- Setting a variable > SET VAR myvar = (SELECT sum(c1) FROM VALUES(1), (2) AS T(c1); > VALUES (myvar); 3 -- Variables are the outermost scope. > SELECT myvar, t.myvar, sessi...
KillQueryNotificationSubscriptionStatement KillStatement KillStatsJobStatement LabelStatement LedgerOption LedgerTableOption LedgerViewOption LeftFunctionCall LikePredicate LineNoStatement ListenerIPEndpointProtocolOption ListTypeCopyOption 文本 LiteralAtomicBlockOption ...
Transact-SQL 变量的值(DiscountPrice)。sql:variable()方法用于将此值绑定到 XML。 XMLProductModelName类型列中的值()使查询更有趣。 以下是查询语句: SQL DECLARE@price moneySET@price=2500.00SELECTProductID, Production.ProductModel.ProductModelID,CatalogDescription.query(' declare namespace pd="https://sc...
DECLARE@MyTableVarTABLE( EmpIDINTNOTNULL, PRIMARYKEYCLUSTERED (EmpID),UNIQUENONCLUSTERED (EmpID),INDEXCustomNonClusteredIndex NONCLUSTERED (EmpID) ); GO The following query returns information about the indexes created in the previous query.
String empno = '7369'; String query_sql = 'select ename from t_emp where empno = 7369 '; stmt = con.prepareStatement( query_sql ); stmt.executeQuery(); 1 2 3 4 使用绑定变量的写法: String empno = 'xxxxx'; String query_sql = 'select ename from t_emp where empno = ? '; //嵌...