Difference between revisions of "UPDATE"

From braindump
Jump to navigation Jump to search
(Created page with "Category: Module 105.3 Category: SQL {{#set:Related SQL command=INSERT|Related SQL command=DELETE|Related SQL command=SELECT}} UPDATE is refers to the SQL command '''UPD...")
 
 
(2 intermediate revisions by the same user not shown)
Line 25: Line 25:
== Excersises ==
== Excersises ==
# Use the [[sample database]] and insert and populate it with the data from the [[File::/etc/shadow]].
# Use the [[sample database]] and insert and populate it with the data from the [[File::/etc/shadow]].

== Additional Information ==
* [http://en.wikipedia.org/wiki/Update_%28SQL%29 Wikipedia on SQL UPDATE]
* [http://www.w3schools.com/SQL/sql_update.asp W3Schools on SQL UPDATE]
* [http://dev.mysql.com/doc/refman/5.0/en/update.html MySQL 5.0 UPDATED documenation]
* [http://www.postgresql.org/docs/9.0/static/sql-update.html PostgreSQL 9.0 UPDATE documentation]
* [http://www.sqlite.org/lag_update.html SQLite3 UPDATE documentation]

Latest revision as of 02:51, 19 January 2011

{{#set:Related SQL command=INSERT|Related SQL command=DELETE|Related SQL command=SELECT}}

UPDATE is refers to the SQL command UPDATE.

Summary

The UPDATE command is used to update existing records in a table. Syntax may vary between certain types of databases but is generally uniform across multiple vendors.

Syntax

  UPDATE <table> 
    SET <column> = <value> [, <column> = <value>] [, ...]]
    [ WHERE <condition> ]

Examples

To update the value from "foo" to "foobar" in column "bar" in table "baz" do the following:

  INSERT INTO baz ( bar ) VALUES( "foo" )
  UPDATE baz SET bar = "foobar" WHERE bar = "foo" 

Note: This will udpdate all the instances where bar has a value of "foo" to "foobar"

Excersises

  1. Use the sample database and insert and populate it with the data from the [[File::/etc/shadow]].

Additional Information