DECLARE@MyVariableTINYINT;IF300BETWEEN0AND255BEGINSET@MyVariable=300;-- 先检查再赋值ENDELSEBEGINPRINT'值超出范围。';END 1. 2. 3. 4. 5. 6. 7. 8. 9. 3. 语法检查 确保SQL 语句的语法正确,能够正常执行。达到这一点的方法包括使用 SQL Server 提供的管理工具或查看错误提示信息。 示例代码 为了...
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 @VAR1=’Y’,@VAR2=’N’ SET @VAR1=’Y’;SET @VAR2=’N’; 2.表达式返回多个值时,用SET将会出错,而SE...
Finally, let's look at how to declare an INT variable in SQL Server and assign an inital value. For example: DECLARE @site_value INT = 10; This variable declaration example would declare a variable called@site_valuethat is an INT datatype. It would then set the value of the@techonthe...
在所有的這些陳述式中,如果參考的資料指標變數存在,但目前未向其配置資料指標,SQL Server 便會引發錯誤。 如果所參考的資料指標變數不存在,SQL Server 便會產生針對其他類型的未宣告變數所產生的相同錯誤。資料指標變數:可以是資料指標類型或另一個資料指標變數的目標。 如需詳細資訊,請參閱SET @loc...
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 @id = column_id from table where column_user = ‘ABC’...
Production.Product vWHEREpv.ProductID = v.ProductIDANDpv.VendorID = @vendor_id-- Variable value from the outer cursorOPENproduct_cursorFETCHNEXTFROMproduct_cursorINTO@productIF@@FETCH_STATUS <>0PRINT' <<None>>'WHILE@@FETCH_STATUS =0BEGINSELECT@message =' '+ @product PRINT @messageFETCHNEXTFR...
DECLARE product_cursor CURSOR FOR SELECT v.Name FROM Purchasing.ProductVendor pv, Production.Product v WHERE pv.ProductID = v.ProductID AND pv.VendorID = @vendor_id -- Variable value from the outer cursor OPEN product_cursor FETCH NEXT FROM product_cursor INTO @product IF @@FETCH_...
DECLARE { { @local_variable [AS] data_type } [ = value [ COLLATE <collation_name> ] ] } [ ,...n ] Note To view Transact-SQL syntax for SQL Server 2014 (12.x) and earlier versions, see Previous versions documentation.Arguments@local_variableThe...
Transact-SQL-SyntaxkonventionenSyntaxDie folgende Syntax gilt für SQL Server und Azure SQL-Datenbank:syntaxsql Kopie DECLARE { { @local_variable [AS] data_type [ = value ] } | { @cursor_variable_name CURSOR } } [ ,...n ] | { @table_variable_name [AS] } ::= TABLE ( { <...
DECLARE product_cursor CURSOR FOR SELECT v.Name FROM Purchasing.ProductVendor pv, Production.Product v WHERE pv.ProductID = v.ProductID AND pv.VendorID = @vendor_id -- Variable value from the outer cursor OPEN product_cursor FETCH NEXT FROM product_cursor INTO @product IF @@FETCH_STATUS <...