SQL - Data Manipulation

Data Manipulation

The Data Manipulation Language (DML) is the subset of SQL used to add, update and delete data:

INSERT adds rows (formally tuples) to an existing table, e.g.:

INSERT INTO My_table (field1, field2, field3) VALUES ('test', 'N', NULL);

UPDATE modifies a set of existing table rows, e.g.:

UPDATE My_table SET field1 = 'updated value' WHERE field2 = 'N';

DELETE removes existing rows from a table, e.g.:

DELETE FROM My_table WHERE field2 = 'N';

MERGE is used to combine the data of multiple tables. It combines the INSERT and UPDATE elements. It is defined in the SQL:2003 standard; prior to that, some databases provided similar functionality via different syntax, sometimes called "upsert".

MERGE INTO TABLE_NAME USING table_reference ON (condition) WHEN MATCHED THEN UPDATE SET column1 = value1 WHEN NOT MATCHED THEN INSERT (column1 ) VALUES (value1 [, value2 ...

Famous quotes containing the words data and/or manipulation:

“This city is neither a jungle nor the moon.... In long shot: a cosmic smudge, a conglomerate of bleeding energies. Close up, it is a fairly legible printed circuit, a transistorized labyrinth of beastly tracks, a data bank for asthmatic voice-prints.”
—Susan Sontag (b. 1933)

“When we say “science” we can either mean any manipulation of the inventive and organizing power of the human intellect: or we can mean such an extremely different thing as the religion of science the vulgarized derivative from this pure activity manipulated by a sort of priestcraft into a great religious and political weapon.”
—Wyndham Lewis (1882–1957)