这里有一个稍微不同的答案。您的列名和长度可能都匹配，但可能您在SELECT语句中以错误的顺序指定了列。假设tableX和tableY的列名称相同，但顺序不同

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 ...

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

是的，“一品脱的酒放进半品脱的锅里是不行的”。我对人们建议的各种sp没有太多的运气(无论出于什么原因)，但只要两个表在同一个DB中(或者您可以将它们放到同一个DB中)，您就可以使用INFORMATION_SCHEMA。列来定位错误字段，因此:

select c1.table_name,c1.COLUMN_NAME,c1.DATA_TYPE,c1.CHARACTER_MAXIMUM_LENGTH,c2.table_name,c2.COLUMN_NAME, c2.DATA_TYPE,c2.CHARACTER_MAXIMUM_LENGTH
from [INFORMATION_SCHEMA].[COLUMNS] c1
left join [INFORMATION_SCHEMA].[COLUMNS] c2 on 
c1.COLUMN_NAME=c2.COLUMN_NAME
where c1.TABLE_NAME='MyTable1'
and c2.TABLE_NAME='MyTable2'
--and c1.DATA_TYPE<>c2.DATA_TYPE
--and c1.CHARACTER_MAXIMUM_LENGTH <> c2.CHARACTER_MAXIMUM_LENGTH
order by c1.COLUMN_NAME

这将允许您上下滚动，比较字段的长度。注释的部分可以让您查看(显然是在未注释的情况下)是否存在数据类型不匹配，或者特别显示字段长度不同的数据类型(因为我懒得滚动)，只需注意，所有内容都基于与目标列名匹配的源列名。

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

SQL Server 2019将最终返回更有意义的错误消息。

二进制或字符串数据将被截断=>错误消息增强 如果您(在生产环境中)出现了该错误，则不太容易看到该错误来自哪一列或哪一行，以及如何准确定位它。

要启用新行为，需要使用DBCC TRACEON(460)。sys.messages中的新错误文本:

SELECT * FROM sys.messages WHERE message_id = 2628

2628 -字符串或二进制数据将在表' %中被截断。*ls '，列' %.*ls '。截断值:' %.*ls '。

字符串或二进制数据将被截断:替换臭名昭著的错误8152

这个新消息也会被反向移植到SQL Server 2017 CU12(以及即将发布的SQL Server 2016 SP2 CU)，但不是默认情况下。您需要启用跟踪标志460，以便在会话级别或服务器级别将消息ID 8152替换为2628。 请注意，目前即使在SQL Server 2019 CTP 2.0中也需要启用相同的跟踪标志460。在未来的SQL Server 2019版本中，默认情况下，消息2628将取代消息8152。

SQL Server 2017 CU12也支持该特性。

改进:在SQL Server 2017中用扩展信息替换“字符串或二进制数据将被截断”消息

此SQL Server 2017更新引入了一条可选消息，其中包含以下附加上下文信息。 Msg 2628，级别16，状态6，程序程序命名，行Linenumber 字符串或二进制数据将在表'%中被截断。*ls'，列'%.*ls'。 截断值:'%.*ls'。 新的消息ID是2628。如果启用了跟踪标志460，此消息将替换任何错误输出中的消息8152。

db < > fiddle演示

ALTER DATABASE SCOPED CONFIGURATION VERBOSE_TRUNCATION_WARNINGS = { ON | OFF } APPLIES TO: SQL Server (Starting with SQL Server 2019 (15.x)) and Azure SQL Database Allows you to enable or disable the new String or binary data would be truncated error message. SQL Server 2019 (15.x) introduces a new, more specific error message (2628) for this scenario: String or binary data would be truncated in table '%.*ls', column'%.*ls'. Truncated value: '%.*ls'. When set to ON under database compatibility level 150, truncation errors raise the new error message 2628 to provide more context and simplify the troubleshooting process. When set to OFF under database compatibility level 150, truncation errors raise the previous error message 8152. For database compatibility level 140 or lower, error message 2628 remains an opt-in error message that requires trace flag 460 to be enabled, and this database scoped configuration has no effect.