存储过程:把表名变成表变量 [英] Stored Procedure: turn Table name into Table Variable

问题描述

有很多类似的问题，但是我并没有完全找到我想要的.由于在存储过程中使用动态 SQL 会很快变得麻烦，我想将表名 (Varchar) 传递给存储过程，将该表名转换为表变量，然后在该过程的其余部分使用该表变量.我无法弄清楚这个代码.

There are quite a few similar Questions, however i didn't quite find what i was looking for. Since using dynamic SQL in a stored procedure can quickly get cumbersome, I want to pass a table name (Varchar) to a stored procedure, turn that Tablename into a Tablevariable and afterwards work with this Tablevariable for the rest of the procedure. I can't figure out the code for this.

我在 SQL Server 2008R2 上使用 SSMS.目前我的代码看起来与此类似.我滞后中间部分从@TableName Varchar 变量创建@Table 表变量

I'm working in SSMS on a SQL Server 2008R2. Currently my code looks similar to this. I lag the middle part to create the @Table Table Variable from the @TableName Varchar Variable

CREATE Procedure [dbo].StoredProc(@Tablename Varchar)
AS
Begin
Declare @Table Table (ColA Varchar, ColB Float)
Declare @result float

-- Something like Insert @Table Select * From @Tablename using Dynamic sql or sth. similar

Select @result = Select sum(ColB) From @Table
End

推荐答案

您可以通过以下方式组合动态 SQL 和临时表存储:

You can combine dynamic SQL and Temporary table storage the following way:

CREATE Procedure [dbo].StoredProc(@Tablename Varchar(100))
    AS
    Begin
    create table #TempTbl (ColA Varchar(100), ColB Float);
    Declare @result float

    declare @dynSQL varchar(max);
    select @dynSQL = 'insert into #TempTbl select 
      cast(val1 as varchar(100)) as ColA, 
      cast(val2 as float) as ColB from ' + COALESCE( @Tablename, 'NULL');
    -- Tablename should contain schema name, 'dbo.' for example
    exec( @dynSQL );
    Select @result = sum(ColB) From #TempTbl
    drop table #TempTbl;
    return @Result;
    End

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