Computer Science
UPDATE(l) UPDATE(l)
NAME
UPDATE - Replaces values of columns in a table
SYNOPSIS
UPDATE table SET R">colle> = expression [, ...]
[ FROM fromlist ]
[ WHERE condition ]
INPUTS
table The name of an existing table.
column The name of a column in table.
expression
A valid expression or value to assign to column.
fromlist
A Postgres non-standard extension to allow columns
from other tables to appear in the WHERE condition.
condition
Refer to the SELECT statement for a further
description of the WHERE clause.
OUTPUTS
UPDATE #
Message returned if successful. The # means the
number of rows updated. If # is equal 0 no rows
are updated.
DESCRIPTION
UPDATE changes the values of the columns specified for all
rows which satisfy condition. Only the columns to be modi-
fied need appear as columns in the statement.
Array references use the same syntax found in select(l).
That is, either single array elements, a range of array
elements or the entire array may be replaced with a single
query.
You must have write access to the table in order to modify
it, as well as read access to any table whose values are
mentioned in the WHERE condition.
USAGE
Change word "Drama" with "Dramatic" on column kind:
UPDATE films
SET kind = 'Dramatic'
WHERE kind = 'Drama';
SELECT * FROM films WHERE kind = 'Dramatic' OR kind = 'Drama';
code |title |did| date_prod|kind |len
-----+-------------+---+----------+----------+------
BL101|The Third Man|101|1949-12-23|Dramatic | 01:44
P_302|Becket |103|1964-02-03|Dramatic | 02:28
M_401|War and Peace|104|1967-02-12|Dramatic | 05:57
T_601|Yojimbo |106|1961-06-16|Dramatic | 01:50
DA101|Das Boot |110|1981-11-11|Dramatic | 02:29
COMPATIBILITY
SQL92
SQL92 defines a different syntax for the positioned UPDATE
statement:
UPDATE table SET column = expression [, ...]
WHERE CURRENT OF cursor
where cursor identifies an open cursor.
SQL - Language Statements 15 August 1999 1
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