Why OBJECT_ID used while checking if a table exists or not

Question

I need to check if a table in SQL exist or not.

If not it must create one automatically.

Now I researched and found this code:

IF  NOT EXISTS (SE         


        

Answer 1

The ISO SQL way to check existence of a table level object is the INFORMATION_SCHEMA.TABLES view

There's nothing wrong with looking at sys.objects but.... INFORMATION_SCHEMA.TABLES is a bit more declarative -- and it's cross platform (which often doesn't matter at all but meh still nice.)

I think this is probably more readable for a new coder though:

DECLARE @tableName SYSNAME = 'tbfoo'
DECLARE @schemaNAme SYSNAME = 'fooSchema'

IF EXISTS ( SELECT 1 FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_NAME = @tableName AND TABLE_SCHEMA = @schemaName )
BEGIN
    RAISERROR('%s exists in schema: %s', 0, 1, @tableName, @schemaName)
END
ELSE
BEGIN
    RAISERROR('%s DOES NOT EXIST in schema: %s', 0, 1, @tableName, @schemaName)
END

Don't worry about the RAISERROR command -- its just a nice way of printing formatted messages.

You can query the INFORMATION_SCHEMA view to get a sense of what's in it.

SELECT TOP 5 * FROM INFORMATION_SCHEMA.TABLES

As you can see -- you can reference schemas and catalogs by name rather than looking up their ID with OBJECT_ID()