A SQL statement typically used to `UPDATE` records when they exist and `INSERT` them when they do not.
Officially introduced in the SQL:2003 standard, and expanded in the SQL:2008 standard,
MERGE does an
INSERT for new records and an
UPDATE of existing records depending on whether or not a condition matches.
Database management systems Oracle Database, DB2, Teradata and MS SQL support the standard syntax. Some also add non-standard SQL extensions that allow for things such as a
MERGE is similar to, but not synonymous with