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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