Question

我正在使用Table-Valued Parameter来使用以下代码构建dyNamic查询

AlTER PROCEDURE [dbo].[ABC]  
     @tblName Varchar(1000), 
     @Details ABC_TYPE Readonly


AS 

   BEGIN

   Declare @PK as nvarchar(1000)
   Declare @SyncFlag as nvarchar(1) ='S'
   Declare @SelectCommand as nvarchar(1200)
   Declare @tblName2 as nvarchar(1000) ='@Details_N'    


  Set @PK = 'PK'


  Declare @Details_N as table (Pk int)
  Insert into @Details_N(Pk) 
  select PK from @Details

  set @SelectCommand =   'Update A ' + ' set A.Sync_Flag ='''+ @SyncFlag + ''' From '+ @tblName + ' A, '  + @tblName2 + ' B ' +
  ' where A.' + @PK +'='+  'B.PK' 

  EXEC sp_executesql @SelectCommand;

这给了我错误

必须声明表变量“@Details_N”

找不到我的错误

Answer 1

表变量的范围是针对特定批处理（相同的上下文），而临时表是针对SPID的。 EXEC命令在不同的上下文中运行。改为使用临时表：

Declare @tblName2 as nvarchar(1000) ='#Details_N'  

CREATE TABLE  #Details_N (Pk int)
Insert into #Details_N(Pk) 
select PK from @Details

Answer 2

在动态查询内部，您不能使用外部声明的表变量。请改用临时表。你也有点复杂，这里是一个更清洁的版本

  String query_coinDetailTable = "CREATE TABLE " + COIN_DETAILS_TABLE + "("+ UID + " INTEGER PRIMARY KEY AUTOINCREMENT,"
                + CAP_24HR_CAHNGE + " TEXT," + LONG + " TEXT," + MK_CAP + " TEXT," + PERC + " TEXT," + PRICE + " TEXT,"
                + SHAPESHIFT + " TEXT," + SHORT + " TEXT," + SUPPLY + " TEXT," + USD_VOLUME + " TEXT," + VOLUME + " TEXT,"
                + VWAP_DATA + " TEXT," + VWAP_DATA_BTC + " TEXT," + FAB + " INTEGER DEFAULT 0" + ")";

开始使用DECLARE @SyncFlag AS NVARCHAR(1) ='S' DECLARE @SelectCommand AS NVARCHAR(1200) CREATE TABLE #Details_N(Pk INT) INSERT INTO #Details_N(Pk) SELECT PK FROM @Details SET @SelectCommand = 'Update A ' + ' set A.Sync_Flag = @SyncFlag From '+ Quotename(@tblName) + ' A inner join #Details_N B '+ 'on A.PK =' + 'B.PK' EXEC Sp_executesql @SelectCommand, N'@SyncFlag NVARCHAR(1)', @SyncFlag语法，旧式逗号分隔连接已弃用

如何使用表-Valued参数与动态qry

2 个答案: