SQL：动态 SQL 问题答案

【问题标题】：SQL: Dynamic SQL issueSQL：动态 SQL 问题
【发布时间】：2020-01-23 03:15:39
【问题描述】：

我不确定为什么这不起作用。如果成功保存，我将其设置为返回 1 的结果，但我一直得到 0。这是有效的，但我最近增加了查询的难度。现在它不工作了：

SQL 查询：

DECLARE
    @Email AS NVARCHAR(500) = 'uokgames@gmail.com',
    @Update AS NVARCHAR(MAX) = 'SET Tile_332 = 1,Tile_216 = 1,Tile_296 = 1,Tile_303 = 1,Tile_313 = 1,Tile_274 = 1,Tile_261 = 1,Tile_311 = 1,Tile_320 = 1,Tile_204 = 1,Tile_304 = 1,Tile_187 = 1,Tile_291 = 1',
    @Board AS NVARCHAR(100) = 'Templo_Mayor',
    @Difficulty AS INT = 0
--AS
BEGIN
    DECLARE @sql AS NVARCHAR(MAX),
            @Response AS BIT  = 0

    BEGIN TRY
        SET @sql = 'UPDATE [dbo].[Game_Board] ' +  @Update + ' WHERE [Email] =''' + @Email + ''' AND [Board_Name] = ''' + @Board + ''' AND [Difficulty] = ' + @Difficulty
        EXECUTE sp_executesql @sql  

        SET @Response = 1;
    END TRY
    BEGIN CATCH
        SET @Response = 0;
    END CATCH

    SELECT @Response
END

【问题讨论】：

标签： sql .net

【解决方案1】：

在这里你只需要将难度转换为 varchar(1) 就可以了。

DECLARE
@Email AS NVARCHAR(500) = 'uokgames@gmail.com',
@Update AS NVARCHAR(MAX) = 'SET Tile_332 = 1,Tile_216 = 1,Tile_296 = 1,Tile_303 = 1,Tile_313 = 1,Tile_274 = 1,Tile_261 = 1,Tile_311 = 1,Tile_320 = 1,Tile_204 = 1,Tile_304 = 1,Tile_187 = 1,Tile_291 = 1',
@Board AS NVARCHAR(100) = 'Templo_Mayor',
@Difficulty AS varchar(1) = '0'
--AS
BEGIN
    DECLARE @sql AS NVARCHAR(MAX),
            @Response AS BIT  = 0

    BEGIN TRY
        SET @sql = 'UPDATE [dbo].[Game_Board] ' +  @Update + ' WHERE [Email] =''' + @Email + ''' AND [Board_Name] = ''' + @Board + ''' AND [Difficulty] = ' + @Difficulty
        EXECUTE sp_executesql @sql  

        SET @Response = 1;
    END TRY
    BEGIN CATCH
        SET @Response = 0;
    END CATCH

    SELECT @Response
END

你需要删除 try catch 的东西，这样你才会得到真正的错误：

Msg 245, Level 16, State 1, Line 12
Conversion failed when converting the nvarchar value 'UPDATE [dbo].[Game_Board] SET Tile_332 = 1,Tile_216 = 1,Tile_296 = 1,Tile_303 = 1,Tile_313 = 1,Tile_274 = 1,Tile_261 = 1,Tile_311 = 1,Tile_320 = 1,Tile_204 = 1,Tile_304 = 1,Tile_187 = 1,Tile_291 = 1 WHERE [Email] ='uokgames@gmail.com' AND [Board_Name] = 'Templo_Mayor' AND [Difficulty] = ' to data type int.

【讨论】：

【解决方案2】：

使用参数！

BEGIN TRY
    SET @sql = 'UPDATE [dbo].[Game_Board] ' +  @Update + ' WHERE [Email] = @Email AND [Board_Name] = @Board AND [Difficulty] = @Difficulty';

    EXECUTE sp_executesql @sql,
            N'@Email NVARCHAR(500), @Board NVARCHAR(100), @Difficulty INT,
            @Email=@Email, @Board=@Board, @Difficulty=@Difficulty  

    SET @Response = 1;
END TRY
BEGIN CATCH
    SET @Response = 0;
END CATCH

【讨论】：