SQL statement examples

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Revision as of 09:22, 23 July 2015 by Karl Jones (Talk | contribs) (DELETE statements)

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This article demonstrates a variety of SQL statements.

Overview

SQL statements, broadly speaking, fall into four commonly used categories:

  • SELECT statements return zero or more records
  • INSERT INTO statements insert a new record
  • UPDATE statements update existing records
  • DELETE statements delete existing records

Case insensitivity

SQL statements are typically case-insensitive. These examples follow the common convention of uppercasing SQL keywords.

SELECT statements

SELECT statement return zero or more records.


INSERT INTO statements

INSERT INTO statements insert a new record into a database table.


UPDATE statements

UPDATE statements update zero or more existing records in a database table.


DELETE statements

DELETE statements delete zero or more existing records from a database table.

Syntax:

DELETE FROM table_name WHERE some_column=some_value;<code>

Examples:

Different implementations of SQL

Note that different implementations of SQL -- different "flavors" -- may differ in their details. The examples on this page are appropriate to a wide range -- but not necessarily all -- implementations.

External links