Difference between revisions of "SQL statement examples"
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DELETE statements delete zero or more existing records from a database table. | DELETE statements delete zero or more existing records from a database table. | ||
| + | Syntax: | ||
| + | |||
| + | <code>DELETE FROM table_name | ||
| + | WHERE some_column=some_value;<code> | ||
| + | |||
| + | Examples: | ||
=== Different implementations of SQL === | === Different implementations of SQL === | ||
Revision as of 09:22, 23 July 2015
This article demonstrates a variety of SQL statements.
Contents
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
- SQL SELECT @ W3Schools
- SQL INSERT INTO @ W3Schools
- SQL UPDATE @ W3Schools
- SQL DELETE @ W3Schools
