UPDATE
SQL - Language Statements
UPDATE
Replaces values of columns in a table
1999-07-20
UPDATE [ ONLY ] table SET col = expression [, ...]
[ FROM fromlist ]
[ WHERE condition ]
1998-09-24
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.
1998-09-24
Outputs
UPDATE #
Message returned if successful.
The #
means the number of rows updated.
If #
is equal 0 no rows are updated.
1998-09-24
Description
UPDATE changes the values of the columns specified for
all rows which satisfy condition. Only the columns
to be modified need appear as columns in the statement.
Array references use the same syntax found in
.
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.
By default UPDATE will update tuples in the table specified
and all its sub-classes. If you wish to only update the
specific table mentioned, you should use the ONLY clause.
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
1998-09-24
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.