Varchar değerini hatalı giriş durumunda bir istisna atmadan dönüştürmek

Question

Sql Server işlevlerinin bir istisna atmadan Dönüştür/Dönüştür işlevini çağırmanın bir yolu var mı?

Temel olarak, alfanümerik veri içeren bir sütuna sahibim ve değerleri alandan alıyorum ve verileri tamsayı değeri olarak görüntülemek istiyorum. Bazen ayıklanan veriler bir sayı değildir ve bu durumlarda Sql Server'ın bu satırı atlamasını istiyorum (null veya 0 döndür).

Şu anda Sql select deyimi, bir "nvarchar değeri dönüştürürken Dönüşüm başarısız veri türü int 'xxxxx' ile başarısız olur. Benim istediğim C# 'ın int.TryParse benzer bir şey

olduğunu.

Öneriler SQL Server?

Answer 1

select case when isnumeric(YourColumn + '.0e0') = 1 
      then cast(YourColumn as int) 
      else NULL 
     end /* case */ 
    from YourTable 

Answer 2

2012 işlevleri bu

try_cast
012 için vardırtry_convert
try_parse

Answer 3

Kontrol bunun bir tamsayı olduğundan emin olmak için sizin burada fıkra Ardından aşağıdakileri yapın işlevi

/****** Object: UserDefinedFunction [dbo].[IsInteger] Script Date: 04/10/2013 09:46:19 ******/ 
SET ANSI_NULLS ON 
GO 

SET QUOTED_IDENTIFIER ON 
GO 

CREATE Function [dbo].[IsInteger](@Value VarChar(50)) 
Returns Bit 
As 
Begin 

DECLARE @is_int bit 
SELECT @is_int = CASE 
    WHEN @Value IS NULL THEN 0 
    WHEN @Value = ' ' THEN 0 
    WHEN ISNUMERIC(@Value + '.0e0') = 0  THEN 0 
    WHEN @Value LIKE '%\[^-+ 0-9\]%' THEN 0 
    WHEN CAST(@Value AS NUMERIC(38, 0)) 
     NOT BETWEEN -2147483648. AND 2147483647. THEN 0 
    ELSE 1 
    END 

return @is_int 

End 
GO 

kullanarak döküm önce NEREDE dbo.IsInteger (yourstring) bununla

Answer 4

deneyin oluşturduğum işlev

Resmi bağlantı:Şimdilik

SELECT dbo.TRY_CAST(YourColumn, 'INT', NULL) 

yalnızca veri tipleri INT, TARİH, NUMERIC, BIT destekler ve size yararlı bulacağını umuyorum

FLOAT:https://gist.github.com/jotapardo/800881eba8c5072eb8d99ce6eb74c8bb

DECLARE @strSQL NVARCHAR(1000) 
IF NOT EXISTS (SELECT * FROM dbo.sysobjects WHERE id = OBJECT_ID(N'[dbo].[TRY_CAST]')) 
    BEGIN 
     SET @strSQL = 'CREATE FUNCTION [dbo].[TRY_CAST]() RETURNS INT AS BEGIN RETURN 0 END' 
     EXEC sys.sp_executesql @strSQL 
    END 

SET ANSI_NULLS ON 
GO 
SET QUOTED_IDENTIFIER ON 
GO 

/* 
------------------------------------------------------------------------------------------------------------------------ 
    Description:  
        Syntax 
        --------------- 
        dbo.TRY_CAST(Expression, Data_Type, ReturnValueIfErrorCast) 

        +---------------------------+-----------------------+ 
        | Expression    | VARCHAR(8000)  | 
        +---------------------------+-----------------------+ 
        | Data_Type    | VARCHAR(8000)  | 
        +---------------------------+-----------------------+ 
        | ReturnValueIfErrorCast | SQL_VARIANT = NULL | 
        +---------------------------+-----------------------+ 


        Arguments 
        --------------- 
        expression 
        The value to be cast. Any valid expression. 

        Data_Type 
        The data type into which to cast expression. 

        ReturnValueIfErrorCast 
        Value returned if cast fails or is not supported. Required. Set the DEFAULT value by default. 


        Return Type 
        ---------------- 
        Returns value cast to SQL_VARIANT type if the cast succeeds; otherwise, returns null if the parameter @pReturnValueIfErrorCast is set to DEFAULT, 
        or that the user indicates. 


        Remarks 
        ---------------- 
        dbo.TRY_CAST function simulates the TRY_CAST function reserved of SQL SERVER 2012 for using in SQL SERVER 2008. 
        dbo.TRY_CAST function takes the value passed to it and tries to convert it to the specified Data_Type. 
        If the cast succeeds, dbo.TRY_CAST returns the value as SQL_VARIANT type; if the cast doesn´t succees, null is returned if the parameter @pReturnValueIfErrorCast is set to DEFAULT. 
        If the Data_Type is unsupported will return @pReturnValueIfErrorCast. 
        dbo.TRY_CAST function requires user make an explicit CAST or CONVERT in ANY statements. 
        This version of dbo.TRY_CAST only supports CAST for INT, DATE, NUMERIC and BIT types. 


        Examples 
        ==================================================================================================== 

        --A. Test TRY_CAST function returns null 

         SELECT 
          CASE WHEN dbo.TRY_CAST('6666666166666212', 'INT', DEFAULT) IS NULL 
          THEN 'Cast failed' 
          ELSE 'Cast succeeded' 
         END AS Result; 

        GO 

        --B. Error Cast With User Value 

         SELECT 
          dbo.TRY_CAST('2147483648', 'INT', DEFAULT) AS [Error Cast With DEFAULT], 
          dbo.TRY_CAST('2147483648', 'INT', -1) AS [Error Cast With User Value], 
          dbo.TRY_CAST('2147483648', 'INT', NULL) AS [Error Cast With User NULL Value]; 

         GO 

        --C. Additional CAST or CONVERT required in any assignment statement 

         DECLARE @IntegerVariable AS INT 

         SET @IntegerVariable = CAST(dbo.TRY_CAST(123, 'INT', DEFAULT) AS INT) 

         SELECT @IntegerVariable 

         GO 

         IF OBJECT_ID('tempdb..#temp') IS NOT NULL 
          DROP TABLE #temp 

         CREATE TABLE #temp (
          Id INT IDENTITY 
          , FieldNumeric NUMERIC(3, 1) 
          ) 

         INSERT INTO dbo.#temp (FieldNumeric) 
         SELECT CAST(dbo.TRY_CAST(12.3, 'NUMERIC(3,1)', 0) AS NUMERIC(3, 1));--Need explicit CAST on INSERT statements 

         SELECT * 
         FROM #temp 

         DROP TABLE #temp 

         GO 

        --D. Supports CAST for INT, DATE, NUMERIC and BIT types. 

         SELECT dbo.TRY_CAST(2147483648, 'INT', 0) AS [Cast failed] 
          , dbo.TRY_CAST(2147483647, 'INT', 0) AS [Cast succeeded] 
          , SQL_VARIANT_PROPERTY(dbo.TRY_CAST(212, 'INT', 0), 'BaseType') AS [BaseType]; 

         SELECT dbo.TRY_CAST('AAAA0101', 'DATE', DEFAULT) AS [Cast failed] 
          , dbo.TRY_CAST('20160101', 'DATE', DEFAULT) AS [Cast succeeded] 
          , SQL_VARIANT_PROPERTY(dbo.TRY_CAST('2016-01-01', 'DATE', DEFAULT), 'BaseType') AS [BaseType]; 

         SELECT dbo.TRY_CAST(1.23, 'NUMERIC(3,1)', DEFAULT) AS [Cast failed] 
          , dbo.TRY_CAST(12.3, 'NUMERIC(3,1)', DEFAULT) AS [Cast succeeded] 
          , SQL_VARIANT_PROPERTY(dbo.TRY_CAST(12.3, 'NUMERIC(3,1)', DEFAULT), 'BaseType') AS [BaseType]; 

         SELECT dbo.TRY_CAST('A', 'BIT', DEFAULT) AS [Cast failed] 
          , dbo.TRY_CAST(1, 'BIT', DEFAULT) AS [Cast succeeded] 
          , SQL_VARIANT_PROPERTY(dbo.TRY_CAST('123', 'BIT', DEFAULT), 'BaseType') AS [BaseType]; 

         GO 

        --E. B. TRY_CAST return NULL on unsupported data_types 

         SELECT dbo.TRY_CAST(4, 'xml', DEFAULT) AS [unsupported]; 

         GO 

        ==================================================================================================== 

    Responsible: Javier Pardo 
    Date:   diciembre 29/2016 
    WB tests:  Javier Pardo 

------------------------------------------------------------------------------------------------------------------------ 
*/ 

ALTER FUNCTION dbo.TRY_CAST 
(
    @pExpression AS VARCHAR(8000), 
    @pData_Type AS VARCHAR(8000), 
    @pReturnValueIfErrorCast AS SQL_VARIANT = NULL 
) 
RETURNS SQL_VARIANT 
AS 
BEGIN 
    -------------------------------------------------------------------------------- 
    -- INT 
    -------------------------------------------------------------------------------- 

    IF @pData_Type = 'INT' 
    BEGIN 
     IF ISNUMERIC(@pExpression) = 1 
     BEGIN 
      DECLARE @pExpressionINT AS FLOAT = CAST(@pExpression AS FLOAT) 

      IF @pExpressionINT BETWEEN - 2147483648.0 AND 2147483647.0 
      BEGIN 
       RETURN CAST(@pExpressionINT as INT) 
      END 
      ELSE 
      BEGIN 
       RETURN @pReturnValueIfErrorCast 
      END --FIN IF @pExpressionINT BETWEEN - 2147483648.0 AND 2147483647.0 
     END 
     ELSE 
     BEGIN 
      RETURN @pReturnValueIfErrorCast 
     END -- FIN IF ISNUMERIC(@pExpression) = 1 
    END -- FIN IF @pData_Type = 'INT' 

    -------------------------------------------------------------------------------- 
    -- DATE  
    -------------------------------------------------------------------------------- 

    IF @pData_Type = 'DATE' 
    BEGIN 
     IF ISDATE(@pExpression) = 1 
     BEGIN 
      DECLARE @pExpressionDATE AS DATE = cast(@pExpression AS DATE) 

      RETURN cast(@pExpressionDATE as DATE) 
     END 
     ELSE 
     BEGIN 
      RETURN @pReturnValueIfErrorCast 
     END --FIN IF ISDATE(@pExpression) = 1 
    END --FIN IF @pData_Type = 'DATE' 

    -------------------------------------------------------------------------------- 
    -- NUMERIC 
    -------------------------------------------------------------------------------- 

    IF @pData_Type LIKE 'NUMERIC%' 
    BEGIN 

     IF ISNUMERIC(@pExpression) = 1 
     BEGIN 

      DECLARE @TotalDigitsOfType AS INT = SUBSTRING(@pData_Type,CHARINDEX('(',@pData_Type)+1, CHARINDEX(',',@pData_Type) - CHARINDEX('(',@pData_Type) - 1) 
       , @TotalDecimalsOfType AS INT = SUBSTRING(@pData_Type,CHARINDEX(',',@pData_Type)+1, CHARINDEX(')',@pData_Type) - CHARINDEX(',',@pData_Type) - 1) 
       , @TotalDigitsOfValue AS INT 
       , @TotalDecimalsOfValue AS INT 
       , @TotalWholeDigitsOfType AS INT 
       , @TotalWholeDigitsOfValue AS INT 

      SET @pExpression = REPLACE(@pExpression, ',','.') 

      SET @TotalDigitsOfValue = LEN(REPLACE(@pExpression, '.','')) 
      SET @TotalDecimalsOfValue = CASE Charindex('.', @pExpression) 
             WHEN 0 
              THEN 0 
             ELSE Len(Cast(Cast(Reverse(CONVERT(VARCHAR(50), @pExpression, 128)) AS FLOAT) AS BIGINT)) 
             END 
      SET @TotalWholeDigitsOfType = @TotalDigitsOfType - @TotalDecimalsOfType 
      SET @TotalWholeDigitsOfValue = @TotalDigitsOfValue - @TotalDecimalsOfValue 

      -- The total digits can not be greater than the p part of NUMERIC (p, s) 
      -- The total of decimals can not be greater than the part s of NUMERIC (p, s) 
      -- The total digits of the whole part can not be greater than the subtraction between p and s 
      IF (@TotalDigitsOfValue <= @TotalDigitsOfType) AND (@TotalDecimalsOfValue <= @TotalDecimalsOfType) AND (@TotalWholeDigitsOfValue <= @TotalWholeDigitsOfType) 
      BEGIN 
       DECLARE @pExpressionNUMERIC AS FLOAT 
       SET @pExpressionNUMERIC = CAST (ROUND(@pExpression, @TotalDecimalsOfValue) AS FLOAT) 

       RETURN @pExpressionNUMERIC --Returns type FLOAT 
      END 
      else 
      BEGIN 
       RETURN @pReturnValueIfErrorCast 
      END-- FIN IF (@TotalDigitisOfValue <= @TotalDigits) AND (@TotalDecimalsOfValue <= @TotalDecimals) 

     END 
     ELSE 
     BEGIN 
      RETURN @pReturnValueIfErrorCast 
     END --FIN IF ISNUMERIC(@pExpression) = 1 
    END --IF @pData_Type LIKE 'NUMERIC%' 

    -------------------------------------------------------------------------------- 
    -- BIT 
    -------------------------------------------------------------------------------- 

    IF @pData_Type LIKE 'BIT' 
    BEGIN 
     IF ISNUMERIC(@pExpression) = 1 
     BEGIN 
      RETURN CAST(@pExpression AS BIT) 
     END 
     ELSE 
     BEGIN 
      RETURN @pReturnValueIfErrorCast 
     END --FIN IF ISNUMERIC(@pExpression) = 1 
    END --IF @pData_Type LIKE 'BIT' 


    -------------------------------------------------------------------------------- 
    -- FLOAT 
    -------------------------------------------------------------------------------- 

    IF @pData_Type LIKE 'FLOAT' 
    BEGIN 
     IF ISNUMERIC(REPLACE(REPLACE(@pExpression, CHAR(13), ''), CHAR(10), '')) = 1 
     BEGIN 

      RETURN CAST(@pExpression AS FLOAT) 
     END 
     ELSE 
     BEGIN 

      IF REPLACE(@pExpression, CHAR(13), '') = '' --Only white spaces are replaced, not new lines 
      BEGIN 
       RETURN 0 
      END 
      ELSE 
      BEGIN 
       RETURN @pReturnValueIfErrorCast 
      END --IF REPLACE(@pExpression, CHAR(13), '') = '' 

     END --FIN IF ISNUMERIC(@pExpression) = 1 
    END --IF @pData_Type LIKE 'FLOAT' 

    -------------------------------------------------------------------------------- 
    -- Any other unsupported data type will return NULL or the value assigned by the user to @pReturnValueIfErrorCast 
    -------------------------------------------------------------------------------- 

    RETURN @pReturnValueIfErrorCast 

END 

Ve bu deneyin .