Unique index error on INSERT with SELECT and NOT EXISTS check - sql

Question

I'm getting following error if i'm running a stored-procedure
Cannot insert duplicate key row in object ‘dbo.tabTac’ with unique index
‘IX_tabTac’.
Unique Index IX_tabTac:
CREATE UNIQUE NONCLUSTERED INDEX [IX_tabTac] ON [dbo].[tabTAC]
(
[TAC] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, SORT_IN_TEMPDB = OFF, IGNORE_DUP_KEY = OFF, DROP_EXISTING = OFF, ONLINE = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON, FILLFACTOR = 90) ON [PRIMARY]
Table tabTac:
CREATE TABLE [dbo].[tabTAC](
[idTAC] [int] IDENTITY(1,1) NOT NULL,
[TAC] [char](8) NOT NULL,
[fiModel] [int] NOT NULL,
CONSTRAINT [PK_tabTac] PRIMARY KEY CLUSTERED
(
[idTAC] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON, FILLFACTOR = 90) ON [PRIMARY]
) ON [PRIMARY]
GO
SET ANSI_PADDING OFF
GO
ALTER TABLE [dbo].[tabTAC] WITH NOCHECK ADD CONSTRAINT [FK_tabTac_modModel] FOREIGN KEY([fiModel])
REFERENCES [dbo].[modModel] ([idModel])
GO
ALTER TABLE [dbo].[tabTAC] CHECK CONSTRAINT [FK_tabTac_modModel]
Stored-Procedure InsertTacsFromClaims:
CREATE PROC [dbo].[InsertTacsFromClaims]
with execute as Owner
AS
BEGIN
INSERT INTO tabTac
select substring(t.SSN_Number,1,8)as TAC
,m.idModel as fiModel
from tabData t
inner join modmodel m
ON t.fimodel=m.idmodel
WHERE t.fiproducttype=1
and m.idModel>1
and not exists(
select fiModel from tabTac WHERE TAC=substring(t.SSN_Number,1,8)
)
GROUP BY substring(t.SSN_Number,1,8),m.idModel
END
RETURN ##ROWCOUNT;
I would have thought that i have prevented this error with:
and not exists(
select fiModel from tabTac WHERE TAC=substring(t.SSN_Number,1,8)
)
Edit:
#Sparkys second query(ModelName added) returns following:
TAC fiModel ModelName
01233300 777 U5A
01238300 771 W20I
01238300 784 W20
35427603 720 C903
35773704 781 E15I
35905104 451 W595
35946804 793 W150I
35959004 813 ST18I
Now it's obvious that one TAC in tabData(first 8 chars of SSN_Number)has not a distinct model but can be linked to multiple models. That causes the error because in tabTac the TAC must be unique.
Thanks in advance

Answer 1

Check to see if the SSN_Number is duplicated in the TabData table or if the join to modModel produces duplicates.
select substring(t.SSN_Number,8),count(*)
from tabData
groub by substring(t.SSN_Number,8)
having count(*) > 1
and
select substring(t.SSN_Number,1,8)as TAC
,m.idModel as fiModel
from tabData t
inner join modmodel m
ON t.fimodel=m.idmodel
WHERE t.fiproducttype=1
and m.idModel>1
GROUP BY substring(t.SSN_Number,1,8),m.idModel
HAVING count(*) > 1
If either query returns duplicate SSN_numbers, you'll get the error. Your code only checks that you don't add a SSN number from the table if it already exists in the table you are trying to populate, but doesn't account for potential dupes in the data already
There are several approaches to only get the most recent fiModel code, here is one example:
select SSN_Number,fiModel
FROM tabData td1
JOIN
( -- This will get the latest date from tabData
select SSN_Number,max(received_date) as TheLastestDate
FROM tabData td
LEFT JOIN tabTac tc on tc.TAC = substring(TD.SSN_number,1,8)
and tc.fiModel = td.fModel
WHERE tc.fiModel is NULL
GROUP BY SSN_Number) xx ON xx.SSN_number=td1.ssn_number
and td1.received_date = xx.TheLatestDate
Note that if you have multiple fiModels on the same date, the above won't handle it because it does not know how to distinguish between which to use. Hope this points you in the right direction.