sql update


UPDATEPostgreSQL User's GuidePrevNextUPDATENameUPDATE — Replaces values of columns in a tableUPDATE table SET column = expression [, ...] [ FROM fromlist ] [ WHERE condition ]Inputs table The name of an existing table.columnThe 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 modified need appear as column. 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'; 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 | 02:29CompatibilitySQL92 SQL92 defines a different syntax for positioned UPDATE statement: UPDATE table SET column = expression [, ...] WHERE CURRENT OF cursor where cursor identifies an open cursor.PrevHomeNextUNLISTENUpVACUUM

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