我写了一个有用的存储过程来帮助识别和解决使用INSERT SELECT语句时的文本截断问题(字符串或二进制数据将被截断)。它只比较字段CHAR, VARCHAR, NCHAR和NVARCHAR，并在可能导致错误的情况下逐字段返回一个评估字段。

EXEC dbo.GetFieldStringTruncate SourceTableName, TargetTableName

这个存储过程针对的是在执行INSERT SELECT语句时的文本截断问题。 此存储过程的操作取决于用户之前是否识别出有问题的INSERT语句。然后将源数据插入到全局临时表中。建议使用SELECT INTO语句。 必须在SELECT语句的每个字段的别名中使用目标表字段的相同名称。

函数代码:

DECLARE @strSQL nvarchar(1000)
IF NOT EXISTS (SELECT * FROM dbo.sysobjects where id = OBJECT_ID(N'[dbo].[GetFieldStringTruncate]'))
    BEGIN
        SET @strSQL = 'CREATE PROCEDURE [dbo].[GetFieldStringTruncate] AS RETURN'
        EXEC sys.sp_executesql @strSQL
    END

GO

SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO

/*
------------------------------------------------------------------------------------------------------------------------
    Description:    
                    Syntax 
                    ---------------
                    dbo.GetFieldStringTruncate(SourceTable, TargetTable)
                    +---------------------------+-----------------------+
                    |   SourceTableName         |   VARCHAR(255)        |
                    +---------------------------+-----------------------+
                    |   TargetTableName         |   VARCHAR(255)        |
                    +---------------------------+-----------------------+

                    Arguments
                    ---------------
                    SourceTableName
                    The name of the source table. It should be a temporary table using double charp '##'. E.g. '##temp'

                    TargetTableName
                    The name of the target table. It is the table that receives the data used in the INSERT INTO stament.

                    Return Type
                    ----------------
                    Returns a table with a list of all the fields with the type defined as text and performs an evaluation indicating which field would present the problem of string truncation.

                    Remarks
                    ----------------
                    This stored procedure is oriented to the problem of text truncation when an INSERT SELECT statement is made.
                    The operation of this stored procedure depends on the user previously identifying the INSERT statement with the problem. Then inserting the source data into a global temporary table. The SELECT INTO statement is recommended.
                    You must use the same name of the field of the destination table in the alias of each field of the SELECT statement.

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

                    --A. Test basic

                        IF EXISTS (SELECT * FROM sys.objects  WHERE OBJECT_ID = OBJECT_ID(N'[dbo].[tblDestino]') AND TYPE IN (N'U'))
                            DROP TABLE tblDestino

                        CREATE TABLE tblDestino
                        (
                            Id INT IDENTITY,
                            Field1 VARCHAR(10),
                            Field2 VARCHAR(12),
                            Field3 VARCHAR(11),
                            Field4 VARCHAR(16),
                            Field5 VARCHAR(5),
                            Field6 VARCHAR(1),
                            Field7 VARCHAR(1),
                            Field8 VARCHAR(6),
                            Field9 VARCHAR(6),
                            Field10 VARCHAR(50),
                            Field11 VARCHAR(50),
                            Field12 VARCHAR(50)
                        )

                        INSERT INTO dbo.tblDestino
                        (
                             Field1 ,
                             Field2 ,
                             Field3 ,
                             Field4 ,
                             Field5 ,
                             Field6 ,
                             Field7 ,
                             Field8 ,
                             Field9 ,
                             Field10 ,
                             Field11 ,
                             Field12
                            )
                        SELECT 
                             '123456789' , -- Field1 - varchar(10)
                             '123456789' , -- Field2 - varchar(12)
                             '123456789' , -- Field3 - varchar(11)
                             '123456789' , -- Field4 - varchar(16)
                             '123456789' , -- Field5 - varchar(5)
                             '123456789' , -- Field6 - varchar(1)
                             '123456789' , -- Field7 - varchar(1)
                             '123456789' , -- Field8 - varchar(6)
                             '123456789' , -- Field9 - varchar(6)
                             '123456789' , -- Field10 - varchar(50)
                             '123456789' , -- Field11 - varchar(50)
                             '123456789'  -- Field12 - varchar(50)
                        GO  

                    Result:
                        String or binary data would be truncated


                    *Here you get the truncation error. Then, we proceed to save the information in a global temporary table. 
                    *IMPORTANT REMINDER: You must use the same name of the field of the destination table in the alias of each field of the SELECT statement.


                    Process:

                        IF OBJECT_ID('tempdb..##TEMP') IS NOT NULL DROP TABLE ##TEMP
                        go
                        SELECT 
                             [Field1] = '123456789' ,
                             [Field2] = '123456789' ,
                             [Field3] = '123456789' ,
                             [Field4] = '123456789' ,
                             [Field5] = '123456789' ,
                             [Field6] = '123456789' ,
                             [Field7] = '123456789' ,
                             [Field8] = '123456789' ,
                             [Field9] = '123456789' ,
                             [Field10] = '123456789' ,
                             [Field11] = '123456789' ,
                             [Field12] = '123456789'  
                        INTO ##TEMP

                    Result:
                    (1 row(s) affected)

                    Test:
                        EXEC dbo.GetFieldStringTruncate @SourceTableName = '##TEMP', @TargetTableName = 'tblDestino'

                    Result:

                        (12 row(s) affected)
                        ORIGEN Nombre Campo        ORIGEN Maximo Largo  DESTINO Nombre Campo     DESTINO Tipo de campo   Evaluación
                        -------------------------- -------------------- ------------------------ ----------------------- -------------------------
                        Field1                     9                    02 - Field1              VARCHAR(10)             
                        Field2                     9                    03 - Field2              VARCHAR(12)             
                        Field3                     9                    04 - Field3              VARCHAR(11)             
                        Field4                     9                    05 - Field4              VARCHAR(16)             
                        Field5                     9                    06 - Field5              VARCHAR(5)              possible field with error
                        Field6                     9                    07 - Field6              VARCHAR(1)              possible field with error
                        Field7                     9                    08 - Field7              VARCHAR(1)              possible field with error
                        Field8                     9                    09 - Field8              VARCHAR(6)              possible field with error
                        Field9                     9                    10 - Field9              VARCHAR(6)              possible field with error
                        Field10                    9                    11 - Field10             VARCHAR(50)             
                        Field11                    9                    12 - Field11             VARCHAR(50)             
                        Field12                    9                    13 - Field12             VARCHAR(50)             

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

    ------------------------------------------------------------------------------------------------------------

    Responsible:    Javier Pardo 
    Date:           October 19/2018
    WB tests:       Javier Pardo 

    ------------------------------------------------------------------------------------------------------------

*/

ALTER PROCEDURE dbo.GetFieldStringTruncate
(
    @SourceTableName AS VARCHAR(255)
    , @TargetTableName AS VARCHAR(255)
)
AS
BEGIN
    BEGIN TRY

        DECLARE @colsUnpivot AS NVARCHAR(MAX),
            @colsUnpivotConverted AS NVARCHAR(MAX),
           @query  AS NVARCHAR(MAX)

        SELECT @colsUnpivot = stuff((
                    SELECT DISTINCT ',' + QUOTENAME(col.NAME)
                    FROM tempdb.sys.tables tab
                    INNER JOIN tempdb.sys.columns col
                        ON col.object_id = tab.object_id
                    INNER JOIN tempdb.sys.types typ
                        ON col.system_type_id = TYP.system_type_id
                    WHERE tab.NAME = @SourceTableName
                    FOR XML path('')
                    ), 1, 1, '')
                ,@colsUnpivotConverted = stuff((
                    SELECT DISTINCT ',' + 'CONVERT(VARCHAR(MAX),' + QUOTENAME(col.NAME) + ') AS ' + QUOTENAME(col.NAME)
                    FROM tempdb.sys.tables tab
                    INNER JOIN tempdb.sys.columns col
                        ON col.object_id = tab.object_id
                    INNER JOIN tempdb.sys.types typ
                        ON col.system_type_id = TYP.system_type_id
                    WHERE tab.NAME = @SourceTableName
                    FOR XML path('')
                    ), 1, 1, '')


        --https://stackoverflow.com/questions/11158017/column-conflicts-with-the-type-of-other-columns-in-the-unpivot-list
        IF OBJECT_ID('tempdb..##TablaConMaximos') IS NOT NULL DROP TABLE ##TablaConMaximos

        set @query 
          = 'SELECT u.d AS colname, MAX(LEN(u.data)) as [maximo_largo]
            INTO ##TablaConMaximos
            FROM 
            (
                SELECT ' + @colsUnpivotConverted + '
                FROM ' + @SourceTableName + '
            ) T
            UNPIVOT
             (
                data
                for d in ('+ @colsunpivot +')
             ) u
             GROUP BY u.d'

        PRINT @query

        exec sp_executesql @query;

        ------------------------------------------------------------------------------------------------------------
        SELECT --'Nombre de campo' = RIGHT('00' + ISNULL(CONVERT(VARCHAR,col.column_id),''),2) + ' - ' + col.name + ' '
            --, 'Tipo de campo' = ISNULL(CONVERT(VARCHAR,upper(typ.name)),'') + '(' + ISNULL(CONVERT(VARCHAR,col.max_length),'') + ')'
            [ORIGEN Nombre Campo] = tcm.colname
            , [ORIGEN Maximo Largo] = tcm.maximo_largo
            , [DESTINO Nombre Campo] = DESTINO.[Nombre de campo]
            , [DESTINO Tipo de campo] = DESTINO.[Tipo de campo]
            , [Evaluación] = CASE WHEN DESTINO.maximo_largo < tcm.maximo_largo THEN 'possible field with error' ELSE '' END
            --, * 
        FROM tempdb.sys.tables tab
            INNER JOIN tempdb.sys.columns col
                ON col.object_id = tab.object_id
            INNER JOIN tempdb.sys.types typ
                ON col.system_type_id = TYP.system_type_id
            RIGHT JOIN 
                (
                    SELECT column_id
                        , [Nombre de campo] = RIGHT('00' + ISNULL(CONVERT(VARCHAR,col.column_id),''),2) + ' - ' + col.name + ' '
                        , [Tipo de campo] = ISNULL(CONVERT(VARCHAR,upper(typ.name)),'') + '(' + ISNULL(CONVERT(VARCHAR,col.max_length),'') + ')'
                        , [maximo_largo] = col.max_length
                        , [colname] = col.name
                    FROM sys.tables tab
                        INNER JOIN sys.columns col
                            ON col.object_id = tab.object_id
                        INNER JOIN sys.types typ
                            ON col.system_type_id = TYP.system_type_id
                    WHERE tab.NAME = @TargetTableName
                ) AS DESTINO
                    ON col.name = DESTINO.colname
            INNER JOIN ##TablaConMaximos tcm
                ON tcm.colname = DESTINO.colname

        WHERE tab.NAME = @SourceTableName
            AND typ.name LIKE '%char%'
        ORDER BY col.column_id

    END TRY
    BEGIN CATCH
        SELECT 'Internal error ocurred' AS Message
    END CATCH   

END

目前只支持数据类型CHAR, VARCHAR, NCHAR和NVARCHAR。你可以在下面的链接中找到这段代码的最后一个versión，我们会互相帮助来改进它。GetFieldStringTruncate.sql

https://gist.github.com/jotapardo/210e85338f87507742701aa9d41cc51d

您需要发布源表和目标表的表定义，以便我们找出问题所在，但底线是源表中的一列比目标列大。这可能是您正在以一种您没有意识到的方式更改格式。要弄清楚这一点，您要使用的数据库模型也很重要。

问题很简单:源查询中的一个或多个列包含的数据超过了目标列的长度。一个简单的解决方案是使用源查询并在每一列上执行Max(Len(source col))。也就是说,

Select Max(Len(TextCol1))
    , Max(Len(TextCol2))
    , Max(Len(TextCol3))
    , ...
From ...

然后将这些长度与目标表中的数据类型长度进行比较。至少有一个超出了其目标列的长度。

如果你绝对肯定情况不应该是这样，也不关心是不是这样，那么另一个解决方案是强制强制转换源查询列到它们的目标长度(这将截断任何太长的数据):

Select Cast(TextCol1 As varchar(...))
    , Cast(TextCol2 As varchar(...))
    , Cast(TextCol3 As varchar(...))
    , ...
From ...

面对同样的问题。

日志含义源表中的列长度大于目标表中的列长度 源列长度- 50和 目标列长度- nvarchar(25)，并将其增加到nvarchar(50)，并且它工作

我构建了一个存储过程，它分析一个源表或查询，每个列都有几个特征，其中最小长度(min_len)和最大长度(max_len)。

CREATE PROCEDURE [dbo].[sp_analysetable] (
  @tableName varchar(8000),
  @deep bit = 0
) AS

/*
sp_analysetable 'company'
sp_analysetable 'select * from company where name is not null'
*/

DECLARE @intErrorCode INT, @errorMSG VARCHAR(500), @tmpQ NVARCHAR(2000), @column_name VARCHAR(50), @isQuery bit
SET @intErrorCode=0

IF OBJECT_ID('tempdb..##tmpTableToAnalyse') IS NOT NULL BEGIN
  DROP TABLE ##tmpTableToAnalyse
END
IF OBJECT_ID('tempdb..##tmpColumns') IS NOT NULL BEGIN
  DROP TABLE ##tmpColumns
END

if CHARINDEX('from', @tableName)>0
  set @isQuery=1

IF @intErrorCode=0 BEGIN
  if @isQuery=1 begin
    --set @tableName = 'USE '+@db+';'+replace(@tableName, 'from', 'into ##tmpTableToAnalyse from')
    --replace only first occurance. Now multiple froms may exists, but first from will be replaced with into .. from
    set @tableName=Stuff(@tableName, CharIndex('from', @tableName), Len('from'), 'into ##tmpTableToAnalyse from')
    exec(@tableName)
    IF OBJECT_ID('tempdb..##tmpTableToAnalyse') IS NULL BEGIN
      set @intErrorCode=1
      SET @errorMSG='Error generating temporary table from query.'
    end
    else begin
      set @tableName='##tmpTableToAnalyse'
    end
  end
end

IF @intErrorCode=0 BEGIN
  SET @tmpQ='USE '+DB_NAME()+';'+CHAR(13)+CHAR(10)+'
  select
    c.column_name as [column],
    cast(sp.value as varchar(1000)) as description,
    tc_fk.constraint_type,
    kcu_pk.table_name as fk_table,
    kcu_pk.column_name as fk_column,
    c.ordinal_position as pos,
    c.column_default as [default],
    c.is_nullable as [null],
    c.data_type,
    c.character_maximum_length as length,
    c.numeric_precision as [precision],
    c.numeric_precision_radix as radix,
    cast(null as bit) as [is_unique],
    cast(null as int) as min_len,
    cast(null as int) as max_len,
    cast(null as int) as nulls,
    cast(null as int) as blanks,
    cast(null as int) as numerics,
    cast(null as int) as distincts,
    cast(null as varchar(500)) as distinct_values,
    cast(null as varchar(50)) as remarks
  into ##tmpColumns'
  if @isQuery=1 begin
    SET @tmpQ=@tmpQ+' from tempdb.information_schema.columns c, (select null as value) sp'
  end
  else begin
    SET @tmpQ=@tmpQ+'
      from information_schema.columns c
      left join sysobjects so    on so.name=c.table_name  and so.xtype=''U''
      left join syscolumns sc    on sc.name=c.column_name and sc.id  =so.id 
      left join sys.extended_properties sp on sp.minor_id = sc.colid AND sp.major_id = sc.id and sp.name=''MS_Description''  
      left join information_schema.key_column_usage kcu_fk    on kcu_fk.table_name = c.table_name     and c.column_name = kcu_fk.column_name
      left join information_schema.table_constraints tc_fk    on kcu_fk.table_name = tc_fk.table_name and kcu_fk.constraint_name = tc_fk.constraint_name
      left join information_schema.referential_constraints rc on rc.constraint_name = kcu_fk.constraint_name
      left join information_schema.table_constraints tc_pk    on rc.unique_constraint_name = tc_pk.constraint_name
      left join information_schema.key_column_usage kcu_pk    on tc_pk.constraint_name = kcu_pk.constraint_name
 '
  end
  SET @tmpQ=@tmpQ+' where c.table_name = '''+@tableName+''''

  exec(@tmpQ)
end

IF @intErrorCode=0 AND @deep = 1 BEGIN
  DECLARE
    @count_rows int,
    @count_distinct int,
    @count_nulls int,
    @count_blanks int,
    @count_numerics int,
    @min_len int,
    @max_len int,
    @distinct_values varchar(500)
  DECLARE curTmp CURSOR LOCAL FAST_FORWARD FOR
    select [column] from ##tmpColumns;
  OPEN curTmp
  FETCH NEXT FROM curTmp INTO @column_name
  WHILE @@FETCH_STATUS = 0 and @intErrorCode=0 BEGIN
    set @tmpQ = 'USE '+DB_NAME()+'; SELECT'+
      '  @count_rows=count(0), '+char(13)+char(10)+
      '  @count_distinct=count(distinct ['+@column_name+']),'+char(13)+char(10)+
      '  @count_nulls=sum(case when ['+@column_name+'] is null then 1 else 0 end),'+char(13)+char(10)+
      '  @count_blanks=sum(case when ltrim(['+@column_name+'])='''' then 1 else 0 end),'+char(13)+char(10)+
      '  @count_numerics=sum(isnumeric(['+@column_name+'])),'+char(13)+char(10)+
      '  @min_len=min(len(['+@column_name+'])),'+char(13)+char(10)+
      '  @max_len=max(len(['+@column_name+']))'+char(13)+char(10)+
      ' from ['+@tableName+']'
    exec sp_executesql @tmpQ,
                       N'@count_rows int OUTPUT,
                         @count_distinct int OUTPUT,
                         @count_nulls int OUTPUT,
                         @count_blanks int OUTPUT,
                         @count_numerics int OUTPUT,
                         @min_len int OUTPUT,
                         @max_len int OUTPUT',
                       @count_rows     OUTPUT,
                       @count_distinct OUTPUT,
                       @count_nulls    OUTPUT,
                       @count_blanks    OUTPUT,
                       @count_numerics OUTPUT,
                       @min_len        OUTPUT,
                       @max_len        OUTPUT

    IF (@count_distinct>10) BEGIN
      SET @distinct_values='Many ('+cast(@count_distinct as varchar)+')'
    END ELSE BEGIN
      set @distinct_values=null
      set @tmpQ = N'USE '+DB_NAME()+';'+
        '  select @distinct_values=COALESCE(@distinct_values+'',''+cast(['+@column_name+'] as varchar),  cast(['+@column_name+'] as varchar))'+char(13)+char(10)+
        '  from ('+char(13)+char(10)+
        '    select distinct ['+@column_name+'] from ['+@tableName+'] where ['+@column_name+'] is not null) a'+char(13)+char(10)
      exec sp_executesql @tmpQ,
                         N'@distinct_values varchar(500) OUTPUT',
                         @distinct_values        OUTPUT
    END
    UPDATE ##tmpColumns SET
      is_unique      =case when @count_rows=@count_distinct then 1 else 0 end,
      distincts      =@count_distinct,
      nulls          =@count_nulls,
      blanks         =@count_blanks,
      numerics       =@count_numerics,
      min_len        =@min_len,
      max_len        =@max_len,
      distinct_values=@distinct_values,
      remarks       =
        case when @count_rows=@count_nulls then 'all null,' else '' end+
        case when @count_rows=@count_distinct then 'unique,' else '' end+
        case when @count_distinct=0 then 'empty,' else '' end+
        case when @min_len=@max_len then 'same length,' else '' end+
        case when @count_rows=@count_numerics then 'all numeric,' else '' end
    WHERE [column]=@column_name

    FETCH NEXT FROM curTmp INTO @column_name
  END
  CLOSE curTmp DEALLOCATE curTmp
END

IF @intErrorCode=0 BEGIN
  select * from ##tmpColumns order by pos
end

IF @intErrorCode=0 BEGIN --Clean up temporary tables
  IF OBJECT_ID('tempdb..##tmpTableToAnalyse') IS NOT NULL BEGIN
    DROP TABLE ##tmpTableToAnalyse
  END
  IF OBJECT_ID('tempdb..##tmpColumns') IS NOT NULL BEGIN
    DROP TABLE ##tmpColumns
  END
end

IF @intErrorCode<>0 BEGIN
  RAISERROR(@errorMSG, 12, 1)
END
RETURN @intErrorCode

我把这个过程存储在主数据库中，这样我就可以在每个数据库中使用它，就像这样:

sp_analysetable 'table_name', 1
// deep=1 for doing value analyses

输出为:

column description constraint_type fk_table fk_column pos default null data_type length precision radix is_unique min_len max_len nulls blanks numerics distincts distinct_values remarks id_individual NULL PRIMARY KEY NULL NULL 1 NULL NO int NULL 10 10 1 1 2 0 0 70 70 Many (70) unique,all numeric, id_brand NULL NULL NULL NULL 2 NULL NO int NULL 10 10 0 1 1 0 0 70 2 2,3 same length,all numeric, guid NULL NULL NULL NULL 3 (newid()) NO uniqueidentifier NULL NULL NULL 1 36 36 0 0 0 70 Many (70) unique,same length, customer_id NULL NULL NULL NULL 4 NULL YES varchar 50 NULL NULL 0 NULL NULL 70 0 0 0 NULL all null,empty, email NULL NULL NULL NULL 5 NULL YES varchar 100 NULL NULL 0 4 36 0 0 0 31 Many (31) mobile NULL NULL NULL NULL 6 NULL YES varchar 50 NULL NULL 0 NULL NULL 70 0 0 0 NULL all null,empty, initials NULL NULL NULL NULL 7 NULL YES varchar 50 NULL NULL 0 NULL NULL 70 0 0 0 NULL all null,empty, title_short NULL NULL NULL NULL 8 NULL YES varchar 50 NULL NULL 0 NULL NULL 70 0 0 0 NULL all null,empty, title_long NULL NULL NULL NULL 9 NULL YES varchar 50 NULL NULL 0 NULL NULL 70 0 0 0 NULL all null,empty, firstname NULL NULL NULL NULL 10 NULL YES varchar 50 NULL NULL 0 NULL NULL 70 0 0 0 NULL all null,empty, lastname NULL NULL NULL NULL 11 NULL YES varchar 50 NULL NULL 0 NULL NULL 70 0 0 0 NULL all null,empty, address NULL NULL NULL NULL 12 NULL YES varchar 100 NULL NULL 0 NULL NULL 70 0 0 0 NULL all null,empty, pc NULL NULL NULL NULL 13 NULL YES varchar 10 NULL NULL 0 NULL NULL 70 0 0 0 NULL all null,empty, kixcode NULL NULL NULL NULL 14 NULL YES varchar 20 NULL NULL 0 NULL NULL 70 0 0 0 NULL all null,empty, date_created NULL NULL NULL NULL 15 (getdate()) NO datetime NULL NULL NULL 1 19 19 0 0 0 70 Many (70) unique,same length, created_by NULL NULL NULL NULL 16 (user_name()) NO varchar 50 NULL NULL 0 13 13 0 0 0 1 loyalz-public same length, id_location_created NULL FOREIGN KEY location id_location 17 NULL YES int NULL 10 10 0 1 1 0 0 70 2 1,2 same length,all numeric, id_individual_type NULL FOREIGN KEY individual_type id_individual_type 18 NULL YES int NULL 10 10 0 NULL NULL 70 0 0 0 NULL all null,empty, optin NULL NULL NULL NULL 19 NULL YES int NULL 10 10 0 1 1 39 0 31 2 0,1 same length,

是的，我也面临着这样的问题。

REMARKS VARCHAR(500)
to
REMARKS VARCHAR(1000)

在这里，我将备注文件的长度从500更改为1000