SQL Server中的自动增量列值

Question

我有两列SALARY_CODE和FN_YEAR我想根据FN_YEAR列生成如下表：如果FN_YEAR值为18-19则SALARY_CODE将为SAL/01-18-19 01-18-19，而下一个SALARY_CODE的值为18-19将为SAL/02-18-19

请帮助我编写SQL来执行所讨论的任务。

Answer 1

DECLARE @intCount int=0;
DECLARE @CustomID nvarchar(16);
DECLARE @fn_year nvarchar(16)='19-20';

SELECT @intCount = Count(SALARY_CODE) FROM temptest WHERE FN_YEAR=@fn_year
IF(@intCount = 0)
BEGIN
    set @CustomID='SAL/1-'+ @fn_year
    insert into temptest values (@CustomID,@fn_year)
END
ELSE
BEGIN
        SET @CustomID= 'SAL/'+ CAST(@intCount+1 as nvarchar(16)) +'-'+@fn_year;
        insert into temptest values (@CustomID,@fn_year)
END

您可以编写如下功能：

CREATE FUNCTION dbo.getSalaryCode(@fn_year NVARCHAR(16))  
RETURNS NVARCHAR(16)   
AS   
-- Returns the SALARY_CODE 
BEGIN  
    DECLARE @intCount int=0;
    DECLARE @CustomID nvarchar(16);

    SELECT @intCount = Count(SALARY_CODE) FROM temptest WHERE FN_YEAR=@fn_year
    IF(@intCount = 0)
    BEGIN
        SET @CustomID='SAL/1-'+ @fn_year
    END
    ELSE
    BEGIN
        SET @CustomID= 'SAL/'+ CAST(@intCount+1 as nvarchar(16)) +'-'+@fn_year;
    END
    RETURN @CustomID;  
END; 

Answer 2

您可以使用row_number()并与另一列concatenate以获得所需的结果

with data as ( 
(select '18-19' FN_YEAR union all 
 select '18-19' union all 
 select '18-19' union all 
 select '19-20' union all 
 select '19-20' union all 
 select '20-21')   ) 
 select  FN_YEAR, 
        ('SAL/'+CAST((row_number() OVER (PARTITION BY FN_YEAR order by FN_YEAR)) AS VARCHAR(50))+'-'+FN_YEAR) 
        as SALARY_CODE from data

在这里查看演示

Answer 3

创建一个包含12行（假设需要所有月份）和一个索引列（其编号介于1和12之间）的表（我们将其命名为mnths），并创建另一个表用于所需年份。 然后为每个月和每年在该表中添加行，如下所示：

表名称：mnths

字段名称：mnt（值：1-12）

表名：年

字段名称：yr（值：18-30）

SELECT 'SAL/'+CAST(mnt as nvarchar(2))+'-'+
CAST(yr as nvarchar(2))+'-'+CAST(yr+1 as nvarchar(2)) as SALARY_CODE, 
CAST(yr as nvarchar(2))+'-'+CAST(yr+1 as nvarchar(2)) as FN_YEAR
FROM mnths cross join years

如果您已经有了数据，则可以针对这些表进行验证并添加缺失的条目。

Answer 4

Divya Agrawal的回答很好。 但是我认为您需要的是一个触发器 ，当您在表中插入某些内容时会自动填充这些值。 以下过程是如何执行此操作的示例。 ID是您的表主键。

CREATE TRIGGER [dbo].[Salary_MyTable]
ON [dbo].[MyTable]
AFTER INSERT
AS
BEGIN
@Id
SELECT @Id = INSERTED.Id FROM INSERTED
SELECT @fn_year= INSERTED.FN_YEAR FROM INSERTED
SELECT @intCount = Count(SALARY_CODE) FROM temptest WHERE FN_YEAR=@fn_year

UPDATE [dbo].[MyTable] SET [SALARY_CODE]= 'SAL/' + CAST(@intCount+1 as nvarchar(16)) +'-'+@fn_year) WHERE @Id = Id

END