这发生在我身上，因为我做了一个合并，它更新了我正在进行合并的ID。

失败的例子(注意ClownID):

    MERGE ArchitectMain.dbo.BackendClowns AS TGT 
   USING (
    SELECT ClownID
        ,ClownName
        ,Description
        ,Active
        ,EmailSubject
        ,AddedBy
        ,Added
    FROM #temptable1
    ) AS SRC(ClownID, ClownName, Description, Active, EmailSubject, AddedBy, Added)
    ON (TGT.ClownID = SRC.ClownID)
WHEN MATCHED
    THEN
        UPDATE
        SET ClownID = SRC.ClownID
            ,ClownName = SRC.ClownName
            ,Description = SRC.Description
            ,Active = SRC.Active
            ,EmailSubject = SRC.EmailSubject
            ,AddedBy = SRC.AddedBy
            ,Added = SRC.Added;

示例(注意ClownID):

MERGE ArchitectMain.dbo.BackendClowns AS TGT
USING (
    SELECT ClownID
        ,ClownName
        ,Description
        ,Active
        ,EmailSubject
        ,AddedBy
        ,Added
    FROM #temptable1
    ) AS SRC(ClownID, ClownName, Description, Active, EmailSubject, AddedBy, Added)
    ON (TGT.ClownID = SRC.ClownID)
WHEN MATCHED
    THEN
        UPDATE
        SET ClownName = SRC.ClownName
            ,Description = SRC.Description
            ,Active = SRC.Active
            ,EmailSubject = SRC.EmailSubject
            ,AddedBy = SRC.AddedBy
            ,Added = SRC.Added;
            

--before running this make sure Foreign key constraints have been removed that reference the ID. 

--set table to allow identity to be inserted
SET IDENTITY_INSERT yourTable ON;
GO
--insert everything into a temp table
SELECT * 
INTO #tmpYourTable
FROM yourTable

--clear your table
DELETE FROM yourTable
--insert back all the values with the updated ID column
INSERT INTO yourTable (IDCol, OtherCols)
SELECT ID+1 as updatedID --put any other update logic to the ID here
, OtherCols FROM #tmpYourTable
--drop the temp table
DROP TABLE #tmpYourTable
--put identity back to normal
SET IDENTITY_INSERT yourTable OFF;
GO

如果您特别需要将主键值更改为不同的数字(例如123 -> 1123)。identity属性阻止更改PK值。Set Identity_insert将不起作用。如果您有级联删除，则不建议执行插入/删除操作(除非您关闭了引用完整性检查)。

编辑:新版本的SQL不允许更改syscolumns实体，因此我的部分解决方案必须以艰难的方式完成。关于如何从主键中删除Identity，请参考这个SO: 从表中的列中删除Identity 这个脚本将在PK中关闭标识:

***********************

sp_configure 'allow update', 1
go
reconfigure with override
go


update syscolumns set colstat = 0 --turn off bit 1 which indicates identity column
where id = object_id('table_name') and name = 'column_name'
go


exec sp_configure 'allow update', 0
go
reconfigure with override
go

***********************

接下来，您可以设置关系，以便它们更新外键引用。否则你需要关闭关系强制执行。这个SO链接展示了如何: 如何使用T-SQL临时禁用外键约束?

现在，您可以进行更新。我写了一个简短的脚本来基于相同的列名编写所有的更新SQL(在我的情况下，我需要将CaseID增加1,000,000:

select 
'update ['+c.table_name+'] SET ['+Column_Name+']=['+Column_Name+']+1000000'
from Information_Schema.Columns as c
JOIN Information_Schema.Tables as t ON t.table_Name=c.table_name and t.Table_Schema=c.table_schema and t.table_type='BASE TABLE'
where Column_Name like 'CaseID' order by Ordinal_position

最后，重新启用引用完整性，然后重新启用主键上的Identity列。

注意:我看到有些人在这些问题上问为什么。在我的例子中，我必须将来自第二个生产实例的数据合并到主DB中，这样才能关闭第二个实例。我只需要所有操作数据的PK/ fk不发生冲突。元数据fk是相同的。

ALTER TABLE tablename add newcolumn int
update tablename set newcolumn=existingcolumnname
ALTER TABLE tablename DROP COLUMN existingcolumnname;
EXEC sp_RENAME 'tablename.oldcolumn' , 'newcolumnname', 'COLUMN'
update tablename set newcolumnname=value where condition

然而，上面的代码只有在没有主-外键关系的情况下才能工作

c#程序员使用命令构建器的完整解决方案

首先，你要知道这些事实:

在任何情况下，都不能修改标识列，因此必须删除该行并重新添加新的标识。 不能从列中删除标识属性(必须删除到列) .net中的自定义命令构建器总是跳过标识列，因此不能将其用于此目的。

一旦知道了这个，你要做的就是。要么编写自己的SQL Insert语句，要么编写自己的Insert命令构建器。或者用我为你设计的这个。给定一个数据表，生成SQL插入脚本:

public static string BuildInsertSQLText ( DataTable table )
{
    StringBuilder sql = new StringBuilder(1000,5000000);
    StringBuilder values = new StringBuilder ( "VALUES (" );
    bool bFirst = true;
    bool bIdentity = false;
    string identityType = null;

    foreach(DataRow myRow in table.Rows) 
    {
        sql.Append( "\r\nINSERT INTO " + table.TableName + " (" );

        foreach ( DataColumn column in table.Columns )
        {
            if ( column.AutoIncrement )
            {
                bIdentity = true;

                switch ( column.DataType.Name )
                {
                    case "Int16":
                        identityType = "smallint";
                        break;
                    case "SByte":
                        identityType = "tinyint";
                        break;
                    case "Int64":
                        identityType = "bigint";
                        break;
                    case "Decimal":
                        identityType = "decimal";
                        break;
                    default:
                        identityType = "int";
                        break;
                }
            }
            else
            {
                if ( bFirst )
                    bFirst = false;
                else
                {
                    sql.Append ( ", " );
                    values.Append ( ", " );
                }
                sql.Append ("[");
                sql.Append ( column.ColumnName );
                sql.Append ("]");

                //values.Append (myRow[column.ColumnName].ToString() );

                if (myRow[column.ColumnName].ToString() == "True")
                    values.Append("1");
                else if (myRow[column.ColumnName].ToString() == "False")
                    values.Append("0");
                else if(myRow[column.ColumnName] == System.DBNull.Value)    
                    values.Append ("NULL");
                else if(column.DataType.ToString().Equals("System.String"))
                {
                    values.Append("'"+myRow[column.ColumnName].ToString()+"'");
                }
                else
                    values.Append (myRow[column.ColumnName].ToString());
                    //values.Append (column.DataType.ToString() );
            }
        }
        sql.Append ( ") " );
        sql.Append ( values.ToString () );
        sql.Append ( ")" );

        if ( bIdentity )
        {
            sql.Append ( "; SELECT CAST(scope_identity() AS " );
            sql.Append ( identityType );
            sql.Append ( ")" );
        }
        bFirst = true;
        sql.Append(";");
        values = new StringBuilder ( "VALUES (" );
    } //fin foreach
    return sql.ToString ();
}

DBCC CHECKIDENT(table_name, RESEED, value)

Table_name =给出要重置的表的值

Value =初始值为0，以1开始单位列