舊項目中的數據庫約束名稱不規範，寫了個腳本重新修改。

1. 名稱重新修改為已有的默認值約束的名稱為‘DF_‘ + 表名 + 字段名；

2. 沒有設置默認值約束的列設置默認值，字符串為空，數值為0；

3. 時間字段除了addtime不加默認值；

--修正或添加字段默認值約束的名稱為DF_表名_字段

/*
    SELECT 
    tabName= LOWER(O.name), --表名
    colName=LOWER(C.name), --字段名
    coltype= LOWER(T.name), --類型
    dfVal=ISNULL(D.definition,N‘‘),  --默認值
    dfName=ISNULL(D.name,N‘‘)    --默認值約束名稱
     ,dfSName = (‘DF_‘ + O.name + ‘_‘ + C.name)  --默認值標準名稱    
    FROM sys.columns C 
        INNER JOIN sys.objects O 
            ON C.[object_id]=O.[object_id] 
                AND O.type=‘U‘ 
                AND O.is_ms_shipped=0 
        INNER JOIN sys.types T 
            ON C.user_type_id=T.user_type_id 
        LEFT JOIN sys.default_constraints D 
            ON C.[object_id]=D.parent_object_id 
                AND C.column_id=D.parent_column_id 
                AND C.default_object_id=D.[object_id] 
    WHERE  C.is_identity=0 --非標識列
    AND C.is_computed= 0 --非計算列
    And  O.name IN ( ‘fxs_eshop_task‘) --表名
    --And  O.name IN ( ‘Ck_Proc_List‘,‘fxgw_sys_config‘,‘fxs_duizhang‘,‘Ck_CustomsDocking‘) --表名
    --And  C.name IN (‘Sort_Id‘,‘Type_Code‘)--字段名 Confirm_Time
    And  C.name IN (‘Confirm_Time‘,‘addTime‘,‘settlementbegintime‘,‘hone‘,‘CkNo‘)--字段名 
    AND (D.definition LIKE ‘%NULL%‘)  --獲取為null的約束
    ORDER BY O.name,C.name
 
*/
--修正已有的默認值約束的名稱為‘DF_‘ + 表名 + 字段名 
BEGIN TRAN 

    declare Cols_Cursor cursor FOR         
        SELECT 
        tabName= LOWER(O.name), --表名
        colName=LOWER(C.name), --字段名
        coltype= LOWER(T.name), --類型
        dfVal=ISNULL(D.definition,N‘‘),  --默認值
        dfName=ISNULL(D.name,N‘‘
 
)    --默認值約束名稱
         ,dfSName = (‘DF_‘ + O.name + ‘_‘ + C.name)  --默認值標準名稱     
         
    FROM sys.columns C 
        INNER JOIN sys.objects O 
            ON C.[object_id]=O.[object_id] 
                AND O.type=‘U‘ 
                AND O.is_ms_shipped=0 
        INNER JOIN sys.types T 
            
 
ON C.user_type_id=T.user_type_id 
        LEFT JOIN sys.default_constraints D 
            ON C.[object_id]=D.parent_object_id 
                AND C.column_id=D.parent_column_id 
                AND C.default_object_id=D.[object_id] 
    WHERE  C.is_identity=0 --非標識列
    AND C.is_computed= 0 --非計算列
    --And  O.name IN ( ‘fxs_eshop_task‘) --表名
--    --And  C.name IN (‘Sort_Id‘,‘Type_Code‘)--字段名 Confirm_Time
--    And  C.name IN (‘Confirm_Time‘,‘addTime‘,‘settlementbegintime‘,‘hone‘)--字段名 
    ORDER BY O.name,C.name
    open Cols_Cursor
    declare  @tabName varchar(200), @colName varchar(200), @coltype varchar(200), @dfVal varchar(200), @dfName varchar(200), @dfSName varchar(200)

    fetch next from Cols_Cursor into  @tabName , @colName , @coltype , @dfVal , @dfName , @dfSName 

    while(@@fetch_status=0)
      begin
        --print @tabName + @dfSName
        DECLARE @todo INT,@defaultVal VARCHAR(200),@sql VARCHAR(2000);
        SELECT @todo = 0,@defaultVal = ‘NULL‘,@sql = ‘‘;
        IF( @coltype = ‘money‘ OR @coltype = ‘real‘  OR @coltype = ‘int‘ OR @coltype = ‘decimal‘ OR @coltype = ‘smallint‘ OR @coltype = ‘numeric‘ OR @coltype = ‘tinyint‘ OR @coltype = ‘float‘ OR @coltype = ‘bigint‘ OR @coltype = ‘bit‘) --字符串類型
        BEGIN
            SELECT @todo = 1,@defaultVal = ‘‘‘‘‘‘;
        END
        ELSE IF ( (@coltype = ‘datetime‘ OR @coltype = ‘smalldatetime‘  OR @coltype = ‘datetime2‘) AND @colName = ‘addtime‘)--有些特殊的時間字段，比如發貨時間、審核時間不要有默認值
        BEGIN
            SELECT @todo = 1,@defaultVal = ‘GETDATE()‘;
        END
        ELSE IF ( @coltype = ‘uniqueidentifier‘)
        BEGIN
            SELECT @todo = 1,@defaultVal = ‘NEWID()‘;
        END
        ELSE IF ( @coltype = ‘nchar‘ OR @coltype = ‘char‘  OR @coltype = ‘nvarchar‘  OR @coltype = ‘varchar‘  OR @coltype = ‘text‘  OR @coltype = ‘ntext‘ )
        BEGIN
            SELECT @todo = 1,@defaultVal = ‘‘‘‘‘‘;
        END        
        IF(@dfName = ‘‘)--無默認值約束
        BEGIN
            IF (@todo = 1)
            BEGIN
                SELECT @sql = ‘IF NOT exists (select * from sysobjects where id = object_id(N‘‘[‘ + @dfSName +‘]‘‘)) ALTER TABLE [‘ + @tabName + ‘] ADD CONSTRAINT ‘+@dfSName+‘ DEFAULT ‘+ @defaultVal +‘ FOR [‘+@colName+‘]‘ ;
                print ‘增加約束,‘ +@tabName + ‘表‘ + @colName + ‘無默認值約束,類型為‘ + @coltype + ‘，執行sql:‘ + @sql;
                EXEC(@sql); 
            END 
            ELSE
            BEGIN
                print ‘無約束但不增加,‘ +@tabName + ‘表‘ + @colName + ‘無默認值約束,類型為‘ + @coltype + ‘，不能修改；‘;
            END 
        END 
        ELSE
        BEGIN
            --約束名稱不等於‘DF_‘ + 表名 + 字段名，默認值取原有的
            IF(@dfName <> @dfSName)
            BEGIN
                SELECT @defaultVal = @dfVal;
                SELECT @sql = ‘ALTER TABLE [‘ + @tabName + ‘] DROP CONSTRAINT [‘+@dfName + ‘];‘  --刪除已有約束 
                SELECT @sql = @sql + ‘ IF NOT exists (select * from sysobjects where id = object_id(N‘‘[‘ + @dfSName +‘]‘‘)) ALTER TABLE [‘ + @tabName + ‘] ADD CONSTRAINT ‘+@dfSName+‘ DEFAULT ‘+ @defaultVal +‘ FOR [‘+@colName+‘] ‘ ;
                SELECT @sql = @sql + ‘ Else ALTER TABLE [‘ + @tabName + ‘] ADD CONSTRAINT ‘+ (@dfSName+ ‘2‘) +‘ DEFAULT ‘+ @defaultVal +‘ FOR [‘+@colName+‘] ‘ ;--考慮到某些表和字段加起來正好一樣,所以再後面加2；
            
                print (‘重建約束,‘ +@tabName + ‘表‘ + @colName + ‘有默認值約束‘ + @dfName + ‘,默認值‘ +@dfVal + ‘;刪除後重建約束,執行sql:‘ + @sql);
                EXEC(@sql); -- 
            END
            ELSE
            BEGIN
                print ‘維持約束不變,‘ + @tabName + ‘表‘ + @colName + ‘有默認值約束‘ + @dfName + ‘,默認值‘ +@dfVal + ‘；‘;
            END 
        END 
        fetch next from Cols_Cursor into  @tabName , @colName , @coltype , @dfVal , @dfName , @dfSName 
      end
    close Cols_Cursor
    deallocate Cols_Cursor
ROLLBACK

修正或添加字段默認值約束的名稱