I'm trying to get the last id inserted into a table.
I was using
SELECT IDENT_CURRENT('TABLE')
But the problem is that it doesn't return the last inserted id, it returns the max inserted id.
For example, if i do:
INSERT INTO 'TABLA' (ID) VALUES (100)
SELECT IDENT_CURRENT('TABLE') returns 100
but then if i do
INSERT INTO 'TABLA' (ID) VALUES (50)
SELECT IDENT_CURRENT('TABLE') returns 100
and I want to get 50
I need the ID of a specific table, and I generate the id dinamically, so it's not an identity
How can i do it?
From your code, it looks like ID is not an identity (auto-increment) column, so IDENT_CURRENT isn't going to do what you are expecting.
If you want to find the last row inserted, you will need a datetime column that represents the insert time, and then you can do something like:
SELECT TOP 1 [ID] FROM TABLEA ORDER BY [InsertedDate] DESC
Edited: a few additional notes:
Your InsertedDate column should have a default set to GetDate() unless your application, stored procs or whatever you use to perform inserts will be responsible for setting the value
The reason I said your ID is not an identity/auto-increment is because you are inserting a value into it. This is only possible if you turn identity insert off.
SQL Server does not keep track of the last value inserted into an IDENTITY column, particularly when you use SET IDENTITY_INSERT ON;. But if you are manually specifying the value you are inserting, you don't need SQL Server to tell you what it is. You already know what it is, because you just specified it explicitly in the INSERT statement.
If you can't get your code to keep track of the value it just inserted, and can't change the table to have a DateInserted column with a default of CURRENT_TIMESTAMP (which would allow you to see which row was inserted last), perhaps you could add a trigger to the table that logs all inserts.
SELECT SCOPE_IDENTITY()
will return the last value inserted in current session.
Edit
Then what you are doing is the best way to go just make sure that the ID Column is an IDENTITY Column, IDENT_CURRENT('Table_name'), ##IDENTITY and SCOPE_IDENTITY() returns last value generated by the Identity column.
If the ID column is not an Identity Column, all of these functions will return NULL.
Related
I have a table Line_Production_Plan in SQL Server; it has a UID column (int, auto-increment, identity).
It also has multiple other columns. One of them is execution_priority (int, not null).
When I insert a new row into the table (via a stored procedure (without passing execution_priority or UID as parameters)), I want execution_priority to take up the same value as the corresponding UID column in during insert. Is there a way to set the default value of a column, equal to another upon insert?
The execution, priority needs to be changed from time to time. Hence I can't use identity or auto increment.
You should use IDENT_CURRENT to get the last identity value generated for the table Line_Production_Plan.
Try this code:
INSERT INTO Line_Production_Plan (execution_priority)
VALUES ((SELECT IDENT_CURRENT('Line_Production_Plan')));
I am trying to manually add records to a SQL table
However in this table we have a column called Trackseq this column determines how the data is viewed on our CMS system.
The highest TrackSeq will appear first.
I want to manually add a new row but i want the code to check based on CLNTID what the current trackSeq is and add one to it. So if the trackseq of the last record was 10 I want the new record to go in with a trackseq of 11.
Here is my code.
INSERT INTO tbl_CommTracking ( CLNTID,
TRACKSEQ,
COMMDATE,
COMMTIME,
PRODCODE,
COMMTYPE,
EMPLOYEEID,
COMMDETAILS,
COMMSTATUS)
VALUES ('0000005566','999',GETDATE(),GETDATE(),'BS','Note','0000000786','Testing a manual import','A')
Thanks
Assuming TRACKSEQ is a numeric format, you can read the actual highest value and store it in a variable to use in your insert statement.
Please note that, in case of high concurrency, you may want to synchronize this execution in order to avoid duplicate #ts values.
As stated by #Tim Biegeleisen above, an IDENTITY column is best suited for this kind of tasks, but keep in mind that it may leave holes in number sequence in case of DELETE and failed INSERTS.
Eg:
DECLARE #ts int; --or whatever numeric datatype it is
SELECT #ts = MAX(TRACKSEQ) + 1 FROM tbl_CommTracking
INSERT INTO tbl_CommTracking (
--...
TRACKSEQ
--..
)
VALUES (
--...
#ts
--...
)
You should probably make TRACKSEQ an auto increment column. First drop your current TRACKSEQ column, then add it back:
ALTER TABLE tbl_CommTrackingDROP COLUMN TRACKSEQ;
ALTER TABLE tbl_CommTracking ADD TRACKSEQ INT IDENTITY;
Note that typically you would also make TRACKSEQ the primary key of the table. If you don't want to, that's OK, but then you'll have to make sure you can generate your own unique values for the CLNTID column.
It isn't entirely clear why you need this; if you just want the latest records, use the date/timestamp column available, which would have been set during insertion.
The primary key of my table is an Identity column of an ID. I want to be able to insert a new row and have it know what the last ID in the table currently is and add one to it. I know I can use Scope Identity to get the last inserted column from my code, but I am worried about people manually adding entries in the database, because they do this quite often. Is there a way I can look at the last ID in the table and not just the last ID my code inserted?
With a SQL Identity column, you don't need to do anything special. This is the default behavior. SQL Server will handle making sure you don't have collisions regardless of where the inserts come from.
The ##Identity will pull the latest identity, and scope_identity will grab the identity from the current scope.
A scope is a module: a stored procedure, trigger, function, or batch. Therefore, if two statements are in the same stored procedure, function, or batch, they are in the same scope.
If you don't want to allow manual entries to the primary column, then you can add Identity constraint to it along with primary key constraint.
Example, while creating a table,
CREATE Table t_Temp(RowID Int Primary Key Identity(1,1), Name Varchar(50))
INSERT Into t_Temp values ('UserName')
INSERT Into t_Temp values ('UserName1')
SELECT * from t_Temp
You can query the table and get the next available code in one SQL query:
SELECT COALESCE(MAX(CAST("RowID" AS INT)),0) +1 as 'NextRowID' from <tableName>
The "0" here is a default, meaning if there are no rows found, the first code returned would be (0+1) =1
Generally I have 999 instead of the 0 as I like my RowID/primary key etc. to start at 1000.
CREATE TABLE Table1 :
Id int IDENTITY(1,1),
PK_Column1 nvarchar(50) Primary Key.
INSERT INTO Table1 (PK_Column1) VALUES ('Name'+Id)
Result:
Id PK_Column1
1 Name1
Is this possible? Or do I need to manage the Id column myself for this to work?
From the documentation:
After an INSERT, SELECT INTO, or bulk copy statement completes, ##IDENTITY contains the last identity value generated by the statement.
This applies to all the other identity checkers.
You should probably write a little SP to update the record immediately after your insert if this is what you need. Given that your primary_key appears to be some unusual composite of the ID and a varchar, you would also be best reviewing your data model.
It's important to note the difference with ##IDENTITY and SCOPE_IDENTITY():
##IDENTITY and SCOPE_IDENTITY return the last identity value generated in any table in the current session. However, SCOPE_IDENTITY returns the value only within the current scope; ##IDENTITY is not limited to a specific scope.
How can I get the ##IDENTITY for a specific table?
I have been doing
select * from myTable
as I assume this sets the scope, from the same window SQL query window in SSMS I then run
select ##IDENTITY as identt
It returns identt as null which is not expected since myTable has many entrie in it already..
I expect it to return the next available ID integer.
myTable has a ID column set to Primary key and auto increment.
You can use IDENT_CURRENT
IDENT_CURRENT( 'table_name' )
Note that IDENT_CURRENT returns the last identity value for the table in any session and any scope. This means, that if another identity value was inserted after your identity value then you will not retrieve the identity value that you inserted.
You can only truly use SELECT ##IDENTITY after an insert - the last insert into a table that has an IDENTITY column is the value you'll get back.
You cannot "limit" it to a table - the value in ##IDENTITY - and by the way, I'd strongly recommend using SCOPE_IDENTITY() instead!! - is the last value on any IDENTITY column that was set.
The problem with ##IDENTITY is that it will report back the last IDENTITY value inserted into any table - if your INSERT into your data table will cause e.g. a trigger to write an entry into an Audit table and that Audit table has an IDENTITY field, you'll get back that IDENTITY value - not the one inserted into your table. SCOPE_IDENTITY() solves that.
IDENT_CURRENT does what you want. But don't.
This is in addition to marc_s' answer
I've never known ##IDENTITY to be used this way, i've only ever used it to access the ID of a newly inserted record.
That's correct. ##IDENTITY cannot be used the way you think it can be. It can only be used after an INSERT into a table. Let's consider this for a scenario:
You have two tables: Order (Primary Key: OrderID), OrderDetails (Foreign Key: OrderID)
You perform
INSERT INTO Order
VALUES('Pillows')
-- Note that OrderId is not mentioned in Values since it is auto number (primary key)
Now you want to perform insert into OrderDetail. But you don't always remember how many records there were in Order table prior to you having inserted the record for 'Pillows' and hence you don't remember what was the last PrimaryKey inserted into Order table. You could but even then you wouldn't want to specifically mention to insert (let's say OrderID of 1) when you insert into OrderDetail table.
Hence, your OderDetail insert would work kinda like so:
INSERT INTO OrderDetail
VALUES (##IDENTITY,'Soft Pillows')
Hope this explains the user of ##IDENTITY.