Here is my trigger:
ALTER TRIGGER DONORINFO_INSERT
ON [dbo].[DONORINFO] INSTEAD OF INSERT
AS
DECLARE @sequence AS VARCHAR(50) = ''
DECLARE @tranLen VARCHAR(10)
SET @sequence = (SELECT TOP 1 SUBSTRING([DONORID], 3, 8)
FROM [dbo].[DONORINFO]
ORDER BY [DONORID] DESC)
IF (@sequence IS NULL OR @sequence = '')
BEGIN
SELECT @sequence = REPLICATE('0', 7 ) + '1'
END
ELSE
BEGIN
SELECT @tranLen = LEN(@sequence)
SELECT @sequence = @sequence + 1
SELECT @tranLen = ABS(@tranLen - LEN(CAST(@sequence AS INT)))
SELECT @sequence = REPLICATE('0', @tranLen) + @sequence
END
DECLARE @DONORID AS [nvarchar](50) = 'DN' + CONVERT(VARCHAR, @sequence)
INSERT INTO [dbo].[DONORINFO] ([DONORID], [DONORNAME])
SELECT @DONORID, inserted.DONORNAME
FROM inserted
DONORINFO
INSERT INTO [dbo].[DONORINFO] ([DONORID], [DONORNAME])
VALUES ('DN00000001', 'test')
DONORID DONORNAME
---------------------
DN00000001 test
DN00000002 test
INSERT INTO [dbo].[DONORINFO] ([DONORID], [DONORNAME])
SELECT
'',
[NameOfDonor]
FROM
[dbo].[_TEMPENDOWMENTFUND] AS ENDF
WHERE
[ENDF].[NameOfDonor] NOT IN (SELECT [DONORNAME]
FROM [dbo].[DONORINFO])
_TEMPDOWMENTFUND
DONORID
DONORINFO
Make @sequence
totally int
(and probably rename it to last_id
), add characters in the very end.
To number rows use ROW_NUMBER()
in final select from INSERTED
:
INSERT INTO [dbo].[DONORINFO] ([DONORID], [DONORNAME])
SELECT
'DN' + REPLICATE('0', ABS(@len_you_need - LEN(t.generated_id))) + CAST (t.generated_id as varchar(100)),
t.DONORNAME
FROM
(
SELECT
i.DONORNAME,
@sequence+ROW_NUMBER()OVER(ORDER BY i.DONORNAME) as generated_id
FROM inserted i
) t
@len_you_need
- is the length of DONORID
you need. I guess this may be a constant of 8 characters. In your source you are calculating this here:
SELECT @tranLen = LEN(@sequence)
t.rn
is a "sequence" value generated in subquery given above, which has t
alias. Renamed it to generated_id
for clarity.
This block:
BEGIN
SELECT @tranLen = LEN(@sequence)
SELECT @sequence = @sequence + 1
SELECT @tranLen = ABS(@tranLen - LEN(CAST(@sequence AS INT)))
SELECT @sequence = REPLICATE('0', @tranLen) + @sequence
END
is unnecessary anymore.