6. Data Manipulation (DML) Statements

REVIEW STATUS

All sections from this point forward to the end of the chapter are awaiting technical and editorial review.

DML — data manipulation language — is the subset of SQL that is used by applications and procedural modules to extract and change data. Extraction, for the purpose of reading data, both raw and manipulated, is achieved with the SELECT statement. INSERT is for adding new data and DELETE is for erasing data that are no longer required. UPDATE, MERGE and UPDATE OR INSERT all modify data in various ways.