I've come across the following t-sql:
SELECT {d'9999-12-31'}
Which returns 9999-12-31 00:00:00.000.
This seems to be converting the type of the string literal to a DATETIME. I can't find any documentation on this syntax and I'm wondering if there are any variations, for example if I have a literal 1 but want to represent this in a BIGINT without using CONVERT()/CAST().
Can anyone provide any further information on this syntax? Thanks.
These are ODBC escape sequences. See Date, Time, and Timestamp Escape Sequences for more details.
There is also similar syntax for uniqueidentifiers
SELECT {guid '00000000-0000-0000-0000-000000000000'},
as well as procedure calls and some other constructs detailed off that link.
With regard to the rest of your question I'm not aware of any way of having an integer literal treated as a bigint or of any particular resource that lists all the ways of influencing how literals are assigned datatypes by SQL Server. Some ways are below.
;WITH cte(thing) AS
(
SELECT CAST(1 AS SQL_VARIANT) UNION ALL
SELECT $1 UNION ALL
SELECT 1e0 UNION ALL
SELECT 1.0000 UNION ALL
SELECT 2147483648 UNION ALL
SELECT {ts '2011-09-15 01:23:56.123'} UNION ALL
SELECT {d '2011-09-15'} UNION ALL
SELECT { t '13:33:41' } UNION ALL
SELECT {guid '00000000-0000-0000-0000-000000000000'} UNION ALL
SELECT 'Foo' UNION ALL
SELECT N'Foo'
)
SELECT thing,
sql_variant_property(thing,'basetype') AS basetype,
sql_variant_property(thing,'precision') AS precision,
sql_variant_property(thing,'scale') AS scale,
sql_variant_property(thing,'maxlength') AS maxlength
FROM cte
Returns
thing basetype precision scale maxlength
------------------------------ ------------------- ----------- ------ ---------
1 int 10 0 4
1.00 money 19 4 8
1 float 53 0 8
1.0000 numeric 5 4 5
2147483648 numeric 10 0 5
2011-09-15 01:23:56.123 datetime 23 3 8
2011-09-15 00:00:00.000 datetime 23 3 8
2011-09-15 13:33:41.000 datetime 23 3 8
00000000-0000-0000-0000-000000 uniqueidentifier 0 0 16
Foo varchar 0 0 3
Foo nvarchar 0 0 6
