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SQL里变量的声明以及常用函数举例
知识点：
①声明变量：DECLARE 关键字
②循环语句：WHILE ...
BEGIN ...
END
③数据类型转换：CAST()函数
应用举例：
初始化脚本：
CREATE TABLE [dbo].[TEST]( [ID] [int] IDENTITY(1,1) NOT NULL, [TID] [int] NULL, [Discription] [nvarchar](200) NULL ) --测试数据 DELETE FROM TEST INSERT INTO TEST (TID,Discription)VALUES (1,'记录1-1') INSERT INTO TEST (TID,Discription)VALUES (1,'记录1-2') INSERT INTO TEST (TID,Discription)VALUES (1,'记录1-3') INSERT INTO TEST (TID,Discription)VALUES (1,'记录1-4') INSERT INTO TEST (TID,Discription)VALUES (1,'记录1-5') INSERT INTO TEST (TID,Discription)VALUES (2,'记录2-1') INSERT INTO TEST (TID,Discription)VALUES (2,'记录2-2') INSERT INTO TEST (TID,Discription)VALUES (2,'记录2-3') SELECT * FROM TEST
演练脚本：
DECLARE @startIndex INT,@endIndex INT,@discription NVARCHAR(100);
SELECT @startIndex= MIN(ID)FROM TEST;--最小记录ID
SELECT @endIndex= MAX(ID)FROM TEST;--最大记录ID
WHILE @startIndex <@endIndex
BEGIN
Select @discription=('第'+CAST(ID as NVARCHAR(100))+'行记录：'+CAST(TID as NVARCHAR(100))+'.'+Discription) FROM TEST WHERE ID=@startIndex;
PRINT(@discription);
SELECT @startIndex=@startIndex+1--当前记录加1
END
最后更新：2017-04-02 06:52:22