SqlServer支持like '%'+'87'+'%' 拼接字符串  但MySql里不支持，只能用CONCAT('%','87','%')拼接，否则异常

1.递归函数的区别

类别表

CREATE TABLE [dbo].[stock_category](

[ID] [varchar](50) NOT NULL,

[ParentID] [varchar](50) NULL,

[CategoryName] [nvarchar](128) NOT NULL,

[Depth] [int] NULL,

[SortIndex] [int] NULL,

[UselessYear] [int] NULL,

[CreateDate] [datetime] NULL,

[Remarks] [nvarchar](512) NULL,

CONSTRAINT [PK_stock_category] PRIMARY KEY CLUSTERED

(

[ID] ASC

)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]

) ON [PRIMARY]

GO

SQLServer中：表值递归函数

CREATE function [dbo].[GetCategoryIDList] (@id varchar(50))

returns @t table(id varchar(50))

as

begin

insert @t select ID from dbo.stock_category where ParentID = @id

while @@rowcount > 0

insert @t select a.ID from stock_category as a inner join @t as b

on a.ParentID = b.id and a.ID not in(select id from @t)

return

end

运行：select id from [dbo].GetCategoryIDList('......');

MySQL中：

create funtion 'GetCategoryIDList'(rootId varchar(50))

return varchar(1000)

BEGIN

DECLARE sTemp VARCHAR(1000);

DECLARE sTempChd VARCHAR(1000);

SET sTemp = '$';

SET sTempChd =cast(rootId as CHAR);

WHILE sTempChd is not null DO

SET sTemp = concat(sTemp,',',sTempChd);

SELECT group_concat(ID) INTO sTempChd FROM stock_category where FIND_IN_SET(ParentID,sTempChd)>0;

END WHILE;

RETURN sTemp;

END

运行：select ID from stock_category where find_in_set(ID,GetCategoryIDList('......'));

2.生成GUID

SQLServer:NEWID(); MySQL:UUID();

3.日期函数：

MySQL：Date_Add(now(),interval 1 year);

SQLServer:AddDate(year,1,getdate());