Must declare the variable ’@DimCustomer_test’. 如果我们对上面的查询进行更改,对查询使用别名(并且找开IO): —–in the follow script,we used the table alias. DECLARE @DimCustomer_test TABLE ( [CustomerKey] [int] , [FirstName] [nvarchar](50) ,[MiddleName] [nvarchar](50) ,[LastName] [...
sp_executesql 支持独立于 Transact-SQL 字符串设置参数值,如以下示例所示。 DECLARE @IntVariable int; DECLARE @SQLString nvarchar(500); DECLARE @ParmDefinition nvarchar(500); /* Build the SQL string one time.*/ SET @SQLString = N'SELECT BusinessEntityID, NationalIDNumber, JobTitle, LoginID FRO...
servers = relationship('Server',secondary='servergroup',backref='groups') classServer(Base): __tablename__ ='server' id= Column(Integer,primary_key=True,autoincrement=True)# 设置主键自增 hostname = Column(String(64),unique=True,nullable=False)# 非空约束,唯一约束 classServerGroup(Base): __...
var_name是被临时修改的会话变量名,value是会话变量的取值 greatsql>SELECT@@unique_checks;SELECT/*+ SET_VAR(unique_checks=OFF) */@@unique_checks;SELECT@@unique_checks; SELECT/*+ SET_VAR(sort_buffer_size = 16M) */nameFROMpeopleORDERBYname; INSERT/*+ SET_VAR(foreign_key_checks=OFF) */INTO...
sql_context <context_variable>; USE DEFAULT 表示使用默认的全局的上下文,直到下一个 CONTEXT USE 使用后才会切换上下文。 EXEC SQL ENABLE THREADS 该语句用来初始化多线程环境,必须是应用的第一条可执行的嵌入 SQL 语句。 EXEC SQL CONTEXT ALLOCATE 该语句用来初始化 CONTEXT 变量内存 EXEC SQL CONTEXT USE...
4 使用数据类型Nameperson修改数据库表数据类型 (1) 单击屏幕上方 “工具栏”菜单中的“新建查询”按钮,打开“查询编辑器”窗口,并在“查询编辑器”窗口中输入以下T-SQL语句: USE jxsk GO ALTER TABLE STUDENT ALTER COLUMN SN NAMEPERSON GO ALTER TABLE TEACHER ALTER COLUMN TN NAMEPERSON GO (2) 单击 “...
USEAdventureWorks2022; GOCREATETABLEAdventureWorks2022.dbo.VariableTest (Col1NVARCHAR(50)); GO 在Col1(包含值dbo.VariableTest)的$(tablename)中插入一行。 SQL INSERTINTOAdventureWorks2022.dbo.VariableTest (Col1)VALUES('$(tablename)'); GO 在sqlcmd提示符下,如果没有将任何变量设置为$(tablename),则以...
EXEC (@string_variable); 在以下示例中,我们声明名为 @sqlstring VARCHAR 的变量,然后向其分配一个字符串。 SQL DECLARE@sqlstringASVARCHAR(1000);SET@sqlstring='SELECT customerid, companyname, firstname, lastname FROM SalesLT.Customer;'EXEC(@sqlstring); GO ...
I have a query that may use one of multiple table names. Instead of wrting the query multiple times I'd like to use a variable that holds the table name like in the following code example: string tablename = sometablename // based on some prior conditions ...
USEAdventureWorks2022; GODECLARE@SQLStringASNVARCHAR(500);DECLARE@ParmDefinitionASNVARCHAR(500);DECLARE@SalesOrderNumberASNVARCHAR(25);DECLARE@IntVariableASINT;SET@SQLString = N'SELECT @SalesOrderOUT = MAX(SalesOrderNumber) FROM Sales.SalesOrderHeader WHERE CustomerID = @CustomerID';SET@ParmDefinition =...