动态游标 SQL 服务器

Question

我有一个由这样的字符串创建的全局游标，但是在执行时，我收到此错误消息：

A cursor with the name 'crsDTO' does not exist.

代码：

DECLARE @Cursor NVARCHAR(MAX); 

SET @Cursor = 'DECLARE crsDTO CURSOR FOR SELECT p.ID, p.Price, p.Count FROM Business.Products'; 

exec sp_executesql @Cursor; 

OPEN crsDTO; -- fails here <<<<<<<<

BEGIN TRY
    FETCH NEXT FROM crsDTO INTO @ID, @Price, @Count;

    WHILE 0 = @@fetch_status
    BEGIN
        PRINT(@ID)

        FETCH NEXT FROM crsDTO INTO @ID, @Price, @Count;
    END;

    CLOSE crsDTO;
    DEALLOCATE crsDTO;
END TRY
BEGIN CATCH
    CLOSE crsDTO;
    DEALLOCATE crsDTO;
END CATCH

我环顾四周一切看起来都很好..但我找不到为什么它不起作用。

更新

此 SP 将批量更新价格或库存或两者。我可能是错的，可能有比这更好的替代方法，我愿意接受所有更正。但是，此游标将根据用户意见进行过滤。它可以根据过滤器更改 stock/prices（百分比金额或基本金额）。因此，例如，用户只想批量更改特定 brandId 或 BrandId/CategoryId 和 SupplierId 的组合或它们的 none（这意味着每个产品）的价格。

CREATE procedure [Business].[Product_BulkUpdate]
(   
    @PO_Error             int OUTPUT,
    @PO_ErrorMessage      Nvarchar(Max) OUTPUT,
    @PO_Step              int OUTPUT,
    @CallerUserId         uniqueidentifier,
    @CategoryId           uniqueidentifier = null,
    @BrandId              uniqueidentifier = null,
    @SupplierId           uniqueidentifier = null,
    @ProductName          nvarchar(max) = null,
    @Amount               float = null,
    @AmountPercentage     float = null,
    @IsInStock            bit = null
)
as


DECLARE @ID Uniqueidentifier;
DECLARE @Price int;
DECLARE @Count int;
DECLARE @KW nvarchar(max);
DECLARE @Cursor nvarchar(max);
DECLARE @WhereClause nvarchar(max);

    set @WhereClause = ' 1=1 ';
    if (@ProductName is not null)
        set @WhereClause =@WhereClause + ' And p.Name like N'''+'%'+cast(@ProductName as nvarchar(4000))+'%'+''' ';
    if (@CategoryId is not null)
        set @WhereClause =@WhereClause + ' And c.ID in (SELECT cf.id FROM Business.GetCategoryChilds('''+CAST(@CategoryId as nvarchar(50)) +''') cf) ';
    if(@SupplierId is not null)
        set @WhereClause = @WhereClause + ' AND p.SupplierId in (' + CAST(@SupplierId as nvarchar(50)) + ') ';
    IF(@BrandId is not null)
        set @WhereClause = @WhereClause + ' AND bb.ID in (' + CAST(@BrandId as nvarchar(50)) + ')'; 

    SET @Cursor = ' DECLARE crsDTO cursor for
        SELECT p.ID, p.Price, p.Count FROM Business.Products p
        INNER JOIN Kernel.BaseEntity b on b.ID = p.ID AND b.IsDelete = 0
        LEFT JOIN Business.Brand bb on bb.ID = p.BrandId
        LEFT JOIN Business.Category c on c.ID = p.CategoryId
        LEFT JOIN MarketPlace.Supplier s on s.SupplierId = p.SupplierId

        WHERE '+@WhereClause+' AND c.CategoryTypeId = 10700';   

begin 
    --- Auto generated procedure
    SET NOCOUNT ON;
    SET @PO_Error = 0;
    SET @PO_Step = 0;
    SET @PO_ErrorMessage = '';
    BEGIN TRY  
            exec sp_executesql @Cursor;
            SET @PO_Step = 1;
            OPEN crsDTO;
            BEGIN TRY
                FETCH NEXT FROM crsDTO INTO @ID, @Price, @Count;
                while 0 = @@fetch_status
                BEGIN
                    IF(@IsInStock = 0) BEGIN
                        IF(@Amount is not null and @AmountPercentage is null) BEGIN
                            IF EXISTS (SELECT ID FROM Business.Products WHERE ID = @ID) BEGIN
                                UPDATE Business.Products SET                            
                                    Price = @Price + @Amount
                                WHERE ID = @ID                  
                            END
                        END else IF(@AmountPercentage is not null and @Amount is null) BEGIN
                            IF EXISTS (SELECT ID FROM Business.Products WHERE ID = @ID) BEGIN
                                UPDATE Business.Products SET                            
                                    Price = (@Price * (@AmountPercentage / 100))
                                WHERE ID = @ID              
                            END
                        END
                    END ELSE IF(@IsInStock = 1) BEGIN
                        IF(@Amount is not null and @AmountPercentage is null) BEGIN
                            IF EXISTS (SELECT ID FROM Business.Products WHERE ID = @ID) BEGIN
                                UPDATE Business.Products SET                            
                                    Price = @Price + @Amount,
                                    Count = 0
                                WHERE ID = @ID                  
                            END
                        END else IF(@AmountPercentage is not null and @Amount is null) BEGIN
                            IF EXISTS (SELECT ID FROM Business.Products WHERE ID = @ID) BEGIN
                                UPDATE Business.Products SET                            
                                    Price = (@Price * (@AmountPercentage / 100)),
                                    Count = 0
                                WHERE ID = @ID              
                            END
                        END ELSE IF(@Amount is null and @AmountPercentage is null) BEGIN
                            IF EXISTS (SELECT ID FROM Business.Products WHERE ID = @ID) BEGIN
                                UPDATE Business.Products SET
                                    Count = 0
                                WHERE ID = @ID
                            END
                        END
                    END
                    SET @PO_Step = 2;
                FETCH NEXT FROM crsDTO INTO @ID, @Price, @Count;
                END;
                CLOSE crsDTO;
                DEALLOCATE crsDTO;
            END TRY
            BEGIN CATCH
                CLOSE crsDTO;
                DEALLOCATE crsDTO;
                SET @PO_Error = ERROR_NUMBER();
                SET @PO_ErrorMessage = ERROR_MESSAGE();
            END CATCH   
        END TRY
    BEGIN CATCH
        SET @PO_Error = ERROR_NUMBER();
        SET @PO_ErrorMessage = ERROR_MESSAGE();
    END CATCH
END;

Answer 1

我会添加检查光标是否存在：

-- ....
BEGIN CATCH
    IF CURSOR_STATUS('global','crsDTO')>=-1
    BEGIN
        CLOSE crsDTO;
        DEALLOCATE crsDTO;
    END   
END CATCH

db<>fiddle demo

使用全局 cursor/row-by-row 方法似乎不是最佳解决方案。

动态游标 SQL 服务器

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tsql

sql-server

sql-server-2017