PostgreSQL

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NOTIFY


— notice no NOTIFY event is received


Compatibility


SQL92


There is no UNLISTEN in SQL92.

D.84 UPDATE


Name


UPDATE — Replaces values of columns in a table UPDATE table SET col = 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 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 modified need appear as columns in the statement.


Array references use the same syntax found in SELECT. 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’;

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