The CASE
statement is the closest to IF in SQL and is supported on all versions of SQL Server.
SELECT CAST(
CASE
WHEN Obsolete = 'N' or InStock = 'Y'
THEN 1
ELSE 0
END AS bit) as Saleable, *
FROM Product
You only need to use the CAST
operator if you want the result as a Boolean value. If you are happy with an int
, this works:
SELECT CASE
WHEN Obsolete = 'N' or InStock = 'Y'
THEN 1
ELSE 0
END as Saleable, *
FROM Product
CASE
statements can be embedded in other CASE
statements and even included in aggregates.
SQL Server Denali (SQL Server 2012) adds the IIF statement which is also available in access (pointed out by Martin Smith):
SELECT IIF(Obsolete = 'N' or InStock = 'Y', 1, 0) as Saleable, * FROM Product
Assuming three columns in the table: ID, NAME, ROLE
BAD: This will insert or replace all columns with new values for ID=1:
INSERT OR REPLACE INTO Employee (id, name, role)
VALUES (1, 'John Foo', 'CEO');
BAD: This will insert or replace 2 of the columns... the NAME column will be set to NULL or the default value:
INSERT OR REPLACE INTO Employee (id, role)
VALUES (1, 'code monkey');
GOOD: Use SQLite On conflict clause
UPSERT support in SQLite! UPSERT syntax was added to SQLite with version 3.24.0!
UPSERT is a special syntax addition to INSERT that causes the INSERT to behave as an UPDATE or a no-op if the INSERT would violate a uniqueness constraint. UPSERT is not standard SQL. UPSERT in SQLite follows the syntax established by PostgreSQL.

GOOD but tedious: This will update 2 of the columns.
When ID=1 exists, the NAME will be unaffected.
When ID=1 does not exist, the name will be the default (NULL).
INSERT OR REPLACE INTO Employee (id, role, name)
VALUES ( 1,
'code monkey',
(SELECT name FROM Employee WHERE id = 1)
);
This will update 2 of the columns.
When ID=1 exists, the ROLE will be unaffected.
When ID=1 does not exist, the role will be set to 'Benchwarmer' instead of the default value.
INSERT OR REPLACE INTO Employee (id, name, role)
VALUES ( 1,
'Susan Bar',
COALESCE((SELECT role FROM Employee WHERE id = 1), 'Benchwarmer')
);
Best Solution