Database languages are special-purpose languages, which allow one or more of the following tasks, sometimes distinguished as sublanguages : Data control language (DCL) – controls access to data; Data definition language (DDL) – defines data types such as creating, altering, or dropping and the relationships among them; Data manipulation language (DML) – performs tasks such as inserting, updating, or deleting data occurrences; Data query language (DQL) – allows searching for information and computing derived information.
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