Why does this TSQL fail? - tsql

Question

IF NOT EXISTS(SELECT * FROM SYS.COLUMNS WHERE Name=N'isHidden' AND Object_ID=Object_ID(N'Templates'))
BEGIN
BEGIN TRANSACTION
GO
CREATE TABLE dbo.Tmp_Templates
(
ID int NOT NULL IDENTITY (1, 1),
isHidden bit NULL,
FileName nvarchar(255) NOT NULL,
Name nvarchar(255) NOT NULL,
Description nvarchar(1024) NULL,
UploadedByTVDBUsersID int NOT NULL,
Created datetime NOT NULL
)
GO
SET IDENTITY_INSERT dbo.Tmp_Templates ON
GO
IF EXISTS(SELECT * FROM dbo.Templates)
EXEC('INSERT INTO dbo.Tmp_Templates (ID, FileName, Name, Description, UploadedByTVDBUsersID, Created)
SELECT ID, FileName, Name, Description, UploadedByTVDBUsersID, Created FROM dbo.Templates WITH (HOLDLOCK TABLOCKX)')
GO
SET IDENTITY_INSERT dbo.Tmp_Templates OFF
GO
DROP TABLE dbo.Templates
GO
EXECUTE sp_rename N'dbo.Tmp_Templates', N'Templates', 'OBJECT'
GO
ALTER TABLE dbo.Templates ADD CONSTRAINT
PK__Templates__499219E9 PRIMARY KEY CLUSTERED
(
ID
)
GO
PRINT N' Templates ADD isHidden'
COMMIT
END
Results in error:
Msg 102, Level 15, State 1, Line 7 Incorrect syntax near
'TRANSACTION'. Caution: Changing any part of an object name could
break scripts and stored procedures.
Update:
Excluding the IF statement wrapping the transaction this SQL is generated by Microsoft SQL Server Management Studio.
If I remove the wrapping IF statement then everything works, but I only need the change to happen if the field isn't already there. How can I make the IF statement work properly?
Um... why the -1 and the vote to close?

Answer 1

I had to wrap each part of the transaction in an IF statement so the GOs were not embedded in an IF statement. The following TSQL works just fine. The transaction updates the schema as expected.
BEGIN TRANSACTION
GO
IF NOT EXISTS(SELECT * FROM SYS.COLUMNS WHERE Name=N'isHidden' AND Object_ID=Object_ID(N'Templates'))
BEGIN
CREATE TABLE dbo.Tmp_Templates
(
ID int NOT NULL IDENTITY (1, 1),
isHidden bit NULL,
FileName nvarchar(255) NOT NULL,
Name nvarchar(255) NOT NULL,
Description nvarchar(1024) NULL,
UploadedByTVDBUsersID int NOT NULL,
Created datetime NOT NULL
)
ALTER TABLE dbo.Tmp_Templates ADD PRIMARY KEY (ID)
END
GO
IF NOT EXISTS(SELECT * FROM SYS.COLUMNS WHERE Name=N'isHidden' AND Object_ID=Object_ID(N'Templates'))
BEGIN
SET IDENTITY_INSERT dbo.Tmp_Templates ON
END
GO
IF NOT EXISTS(SELECT * FROM SYS.COLUMNS WHERE Name=N'isHidden' AND Object_ID=Object_ID(N'Templates'))
BEGIN
IF EXISTS(SELECT * FROM dbo.Templates)
EXEC('INSERT INTO dbo.Tmp_Templates (ID, FileName, Name, Description, UploadedByTVDBUsersID, Created)
SELECT ID, FileName, Name, Description, UploadedByTVDBUsersID, Created FROM dbo.Templates WITH (HOLDLOCK TABLOCKX)')
END
GO
IF NOT EXISTS(SELECT * FROM SYS.COLUMNS WHERE Name=N'isHidden' AND Object_ID=Object_ID(N'Templates'))
BEGIN
SET IDENTITY_INSERT dbo.Tmp_Templates OFF
END
GO
IF NOT EXISTS(SELECT * FROM SYS.COLUMNS WHERE Name=N'isHidden' AND Object_ID=Object_ID(N'Templates'))
BEGIN
DROP TABLE dbo.Templates
END
GO
IF NOT EXISTS(SELECT * FROM SYS.COLUMNS WHERE Name=N'isHidden' AND Object_ID=Object_ID(N'Templates'))
BEGIN
EXECUTE sp_rename N'dbo.Tmp_Templates', N'Templates', 'OBJECT'
PRINT N' Templates ADD isHidden'
END
GO
COMMIT

Answer 2

first GO statement split your query to
IF NOT EXISTS(SELECT * FROM SYS.COLUMNS WHERE Name=N'isHidden' AND Object_ID=Object_ID(N'Templates'))
BEGIN
BEGIN TRANSACTION
//error - END missing
And there is BEGIN keyword without END.
You need to remove GO statement.
UPDATE:
IF 1 = 1
BEGIN
SELECT * FROM someTable
GO
END
also generate Msg 102, Level 15, State 1, Line 3
Incorrect syntax near 'someTable'.

Answer 3

SqlServer won't allow you to use sp_rename inside the transaction since it could break things badly.
You can drop and add the table again, on in your case, you can also use a temporale table to do the query work, truncate the old table, and move rows from temp into Templates.
Sample temp table
CREATE TABLE #myTempTable
(
DummyField1 INT,
DummyField2 VARCHAR(20)
)
Reference
http://msdn.microsoft.com/en-us/library/ms188351.aspx