Conditional script with for non existing column (yet)? - sql-server

Question

I'm using SQL server for creating script to run in production .
If a table doesn't contain a specific column, then create that column.
I've already did that :
IF NOT EXISTS (
SELECT 1
FROM INFORMATION_SCHEMA.columns
WHERE COLUMN_NAME = 'SeeMaxDaysBackwardPrice'
AND TABLE_NAME = 'tblsubscriptiontype'
)
BEGIN
ALTER TABLE dbo.tblsubscriptiontype ADD SeeMaxDaysBackwardPrice INT NULL
END
But now I want to insert a new row to that modified table . So now my script looks like this :
IF NOT EXISTS (
SELECT 1
FROM INFORMATION_SCHEMA.columns
WHERE COLUMN_NAME = 'SeeMaxDaysBackwardPrice'
AND TABLE_NAME = 'tblsubscriptiontype'
)
BEGIN
ALTER TABLE dbo.tblsubscriptiontype ADD SeeMaxDaysBackwardPrice INT NULL
SET IDENTITY_INSERT [dbo].[tblSubscriptionType] ON;
BEGIN TRANSACTION
INSERT INTO [dbo].[tblSubscriptionType]
(
...
[SeeMaxDaysBackwardPrice] <-------- ERROR
)
SELECT ...
-365
COMMIT;
RAISERROR (
N'[dbo].[tblSubscriptionType]: Insert Batch: 1.....Done!',
10,
1
)
WITH NOWAIT;
SET IDENTITY_INSERT [dbo].[tblSubscriptionType] OFF;
END
GO
But now I get an error ( which I perfectlly understand) :
Msg 207, Level 16, State 1, Line 29
Invalid column name 'SeeMaxDaysBackwardPrice'.
Sure I can split the script into 2 seperate scripts , but then I'll have this condition twice :
IF NOT EXISTS (
SELECT 1
FROM INFORMATION_SCHEMA.columns
WHERE COLUMN_NAME = 'SeeMaxDaysBackwardPrice'
AND TABLE_NAME = 'tblsubscriptiontype'
)
Question:
Is there any way to make SQL more relaxed about a column that do not exists yet ? (I already know about dynamic query (text) , but I wonder if there is another option.

Answer 1

Just wrap the code in dynamic T-SQL statement:
IF NOT EXISTS (
SELECT 1
FROM INFORMATION_SCHEMA.columns
WHERE COLUMN_NAME = 'SeeMaxDaysBackwardPrice'
AND TABLE_NAME = 'tblsubscriptiontype'
)
BEGIN
ALTER TABLE dbo.tblsubscriptiontype ADD SeeMaxDaysBackwardPrice INT NULL
SET IDENTITY_INSERT [dbo].[tblSubscriptionType] ON;
DECLARE #DynamicTSQLStatement NVARCHAR(MAX);
SET #DynamicTSQLStatement = N'
INSERT INTO [dbo].[tblSubscriptionType]
(
...
[SeeMaxDaysBackwardPrice]
)
SELECT ...
-365
';
BEGIN TRY
BEGIN TRAN;
EXEC sp_executesql #DynamicTSQLStatement;
COMMIT TRAN;
END TRY
BEGIN CATCH
ROLLBACK TRAN;
END CATCH
SET IDENTITY_INSERT [dbo].[tblSubscriptionType] OFF;
END
GO