Sql Server Any data from the row itself with Try Catch? - sql-server-2008-r2

Using Try/Catch with SqlServer 2008R2, is there a trick to getting some information out of the row that caused the error? For example,
BEGIN TRY
INSERT INTO MyTable
SELECT *
FROM #MyTableVar
END TRY
BEGIN CATCH
-- In here, is there some way to know, for example, MyTable.SomeColumn for the offending row?
END CATCH

This is what I ended up doing:
DECLARE #MyResults TABLE (
Id INT IDENTITY( 1, 1 )
TheKey VARCHAR(20),
Success BIT
)
-- Initially set Success to 1 for all rows
INSERT INTO #MyResults
SELECT TheKey, 1
FROM #MyTableVar
DECLARE #CurrentKey VARCHAR(20)
DECLARE #CurrentId INT
DECLARE incoming CURSOR FOR SELECT Id, TheKey FROM #MyResults
OPEN incoming
FETCH incoming into #Id, #CurrentKey
WHILE ##FETCH_STATUS = 0
BEGIN
BEGIN TRY
INSERT INTO OfficialTable
SELECT *
FROM #MyTableVar TV
WHERE TV.TheKey = #CurrentKey
END TRY
BEGIN CATCH
-- On any failure, update the proper row in #MyResults
UPDATE #MyResults
SET Success = 0
WHERE TheKey = #CurrentKey AND Id = #CurrentId
END CATCH
FETCH NEXT FROM incoming INTO #Id, #CurrentKey
END
CLOSE incoming
SELECT * FROM #MyResults
In the CATCH, I know the key to #MyTableVar, so, I should be able to look up anything I need with that.

Related

What does a try catch change in a while statement that uses ##ROWCOUNT?

I want to add a try catch to a while loop. The loop used while on ##ROWCOUNT > 0. In the while I have an update top (100) statement that works well without a try catch around it. When I add the try, the while ends in the first loop. What impact does the try have on ##ROWCOUNT that makes the while loop end even tough the update touched 100 records?
--do we have anything to process?
select top 1 * from SomeTable where processedFlag is null
WHILE(##ROWCOUNT > 0)
BEGIN
begin try
-- here I have an udpate top (100) statement that processes records with null flag in small batches
end try
begin catch
-- update ##ROWCOUNT so the while continues?
select top 1 * from SomeTable where processedFlag is null
end catch
END
I believe it because of
Statements such as USE, SET , DEALLOCATE CURSOR, CLOSE CURSOR,
BEGIN TRANSACTION or COMMIT TRANSACTION reset the ROWCOUNT value to 0.
May be END TRY is among them, but MSDN doesn't list all possible statements.
This will fix the problem:
DECLARE #i INT
SELECT #i = COUNT(*) FROM SomeTable WHERE processedFlag IS NULL
WHILE(#i > 0)
BEGIN
BEGIN TRY
UPDATE...
SET #i = ##ROWCOUNT
END TRY
BEGIN CATCH
SELECT #i = COUNT(*) FROM SomeTable WHERE processedFlag IS NULL
END CATCH
END

rollback a nested transaction in trigger

I have a following situation.
I have a table with trigger for insert.
When I insert a row in it, from this trigger I want to insert some rows into a second table.
For each of these rows I want to do it in it's own transaction in case something go wrong.
I want to have original row in first table and all rows (these withous errors) in the second.
A little code to reproduce:
create table test(id int primary key identity(1,1),name nvarchar(10))
create table test2(id int primary key identity(1,1),
state char(1) check (state in ('a','b')))
go
create trigger test_trigger on test for insert
as
begin
declare #char char(1)
declare curs cursor for (
select 'a'
union
select 'c'
union
select 'b')
open curs
fetch next from curs into #char
while ##FETCH_STATUS = 0
begin
begin try
begin transaction
insert into test2(state)
select #char
commit
end try
begin catch
print 'catch block'
rollback
end catch
fetch next from curs into #char
end
close curs
deallocate curs
end
go
insert into test(name) values('test')
select * from test
select * from test2
go
drop table test
drop table test2
So for the sample data from this snippet, I want to have a row with 'test' in test table and two rows in the test2 table ('a' and 'b').
How can I write a code for that?
Looks like finally I got it to work.
Corrected trigger code:
create trigger test_trigger on test for insert
as
begin
declare #char char(1)
set xact_abort off
declare curs cursor for (
select 'a'
union
select 'c'
union
select 'b')
open curs
fetch next from curs into #char
while ##FETCH_STATUS = 0
begin
save transaction t
begin try
insert into test2(state)
select #char
end try
begin catch
print 'catch block'
rollback transaction t
end catch
fetch next from curs into #char
end
close curs
deallocate curs
end

how to execute the next T-SQL when a before T-SQL throw an error?

I am working with SQlite and I have many T-SQL that I want to execute all of them in this way:
T-SQL1; T-SQL2, ... T-SQLN
My T-SQL are:
insert into myRelationTable(IDTable1, IDTabl2) VALUES (1,1);
insert into myRelationTable(IDTable1, IDTabl2) VALUES (1,2);
insert into myRelationTable(IDTable1, IDTabl2) VALUES (1,3);
...
With this T.SQLs I want to related records from the table1 with the table2. If any of the relations exist, there are no problem all the T-SQL is execute, but if for exameple there are a problem with the second, the first is execute but the third and the next T-SQL are not executed.
My quiestion it's if there are any way to continue execute the T-SQL and don't take care if some of the T-SQL throw an error, because what I want it's to have the relation, if some relation exists it's because other user created it, so at the end it's what I want, that the relation exists, so I would like to continue with the next T-SQL.
Is it possible?
However, if I try to delete a record that does not exists, the next T-SQL are executed, so SQLite does not take care about the error and continue with the following. Why when I try to add a new record it does not work in the same way?
Thanks.
I would strongly recommend checking if it is OK to perform the T-SQL rather than ignoring errors.
You can do this by:
DECLARE #count int
SET #count = (SELECT COUNT(1) FROM myRelationTable WHERE IDTable1 =1 AND IDTabl2 = 1)
IF #count = 0 OR #count IS NULL
BEGIN
INSERT INTO myRelationTable(IDTable1, IDTabl2) VALUES (1,1)
END
SET #count = (SELECT COUNT(1) FROM myRelationTable WHERE IDTable1 =1 AND IDTabl2 = 2)
IF #count = 0 OR #count IS NULL
BEGIN
INSERT INTO myRelationTable(IDTable1, IDTabl2) VALUES (1,2)
END
SET #count = (SELECT COUNT(1) FROM myRelationTable WHERE IDTable1 =1 AND IDTabl2 = 3)
IF #count = 0 OR #count IS NULL
BEGIN
INSERT INTO myRelationTable(IDTable1, IDTabl2) VALUES (1,3)
END
Which can very easily be wrapped within a stored procedure.
As to your question the answer is:
Sure, easily:
BEGIN TRY
insert into myRelationTable(IDTable1, IDTabl2) VALUES (1,1);
END TRY
BEGIN CATCH
--Do nothing
END CATCH
BEGIN TRY
insert into myRelationTable(IDTable1, IDTabl2) VALUES (1,2);
END TRY
BEGIN CATCH
--Do nothing
END CATCH
BEGIN TRY
insert into myRelationTable(IDTable1, IDTabl2) VALUES (1,3);
END TRY
BEGIN CATCH
--Do nothing
END CATCH
Really my problem is that I am using SQLite Expert to execute the T-SQL, but this program detect as error syntax the Begin try line.
Other way to solve the problem is to use the igonre keyword in this way:
insert or ignore into my table...
This makes that if exists an error, the ignore it and execute the next statement. But again, the "ignore" keyword is detected as an syntax error by SQLite Expert.
The "ignore" keyword belongs to the on conflict clouse. There are more information in this link.
Thanks.

Union select statements within the while loop T-SQL

I'm trying to use cursors to dynamically produce a result set. following is the code
DECLARE # MilestoneName VARCHAR(100),
#MilestoneSts VARCHAR(100),
#ProjectPre VARCHAR(10),
#ProjectID VARCHAR(10),
#Center VARCHAR(20),
#CenterPre VARCHAR(20),
#Source VARCHAR(20),
#Actual INT;
SET #MilestoneName = null;
SET #MilestoneSts = null;
SET #ProjectPre = null;
SET #CenterPre = null;
DECLARE s_cursor CURSOR FOR
SELECT ProjectID, Center, Source, Actual
FROM #MILESTONE
OPEN s_cursor
FETCH NEXT FROM s_cursor INTO #ProjectID, #Center, #Source, #Actual
WHILE ##FETCH_STATUS = 0
BEGIN
SELECT ##FETCH_STATUS sts, #ProjectID PID, #Center Center, #Source Source, #Actual Actual
FETCH NEXT FROM s_cursor INTO #ProjectID, #Center, #Source, #Actual
END
CLOSE s_cursor
DEALLOCATE s_cursor
However using that I'm able to produce 79 results of single rows but I want to union all those rows into one result.. any possible solution will be highly appreciated..
just checking, why are you using a cursor for this?
This sproc could be replaced by just saying
SELECT ProjectID, Center, Source, Actual
FROM #MILESTONE
But maybe I'm missing somehting here?
If there's logic you left out in your code look at this post: Multi-statement Table Valued Function vs Inline Table Valued Function
GJ

Loop in T-SQL, how get field value

In an SQL Server 2005 database, I have a stored procedure. I get some date in put them in a temp table. I'd like loop in this temp table and depending of the value of some fields change the value of others and make some check. I have to do this for each row.
How can I do this ?
thanks,
UPDATE1
BEGIN
SET NOCOUNT ON
--Create temp table
CREATE TABLE #MyTempTable(
id int IDENTITY(1, 1),
PriceMax int,
PriceMin int
)
-- Insert in temp table
INSERT INTO #tmpReconciliation (PriceMax, PriceMin)
SELECT PriceMax = PriceMaxProduct,
PriceMin = PriceMinProduct
FROM Products
DECLARE #RowNum int
SELECT #RowNum = Count(*) From #MyTempTable
WHILE #RowNum > 0
BEGIN
if(....)
PriceMin = 0
....
END
--Drop temp table
DROP TABLE #MyTempTable
END
I read MSDN documentation for WHILE loop and CURSOR.
For example, let's imagine your temp table is named Employee :
DECLARE #Emp_id int
DECLARE Employee_Cursor CURSOR FOR
SELECT EmployeeID
FROM Employee;
OPEN Employee_Cursor;
FETCH NEXT FROM Employee_Cursor INTO #Emp_id;
WHILE ##FETCH_STATUS = 0
BEGIN
-- Here your actions
PRINT #Emp_id
FETCH NEXT FROM Employee_Cursor INTO #Emp_id;
END;
CLOSE Employee_Cursor;
DEALLOCATE Employee_Cursor;
GO
Here I decided to print EmployeeId, but everything is possible.
Tell us what are your checks, and what your temp table looks like if you need more help.
Can't you just use a cursor and inside the cursor run an update statement??
Cursors: http://www.jackdonnell.com/articles/SQL_CURSOR.htm