Update rows of a table.


UPDATE table_ident [ [AS] table_alias ] SET
    { column_ident = expression } [, ...]
  [ WHERE condition ]


UPDATE changes the values of the specified columns in all rows that satisfy the condition. Only the columns to be modified need be mentioned in the SET clause; columns not explicitly modified retain their previous values.


table_ident:The identifier (optionally schema-qualified) of an existing table.
table_alias:A substitute name for the target table. When an alias is provided, it completely hides the actual name of the table. For example, given UPDATE foo AS f, the remainder of the ‘UPDATE’ statement must refer to this table as ‘f’ not ‘foo’.
column_ident:The name of a column in the table identified by table_ident. Subfields can also be defined by using the subscript notation with square brackets.
expression:An expression to assign to the column.
condition:An expression that returns a value of type boolean. Only rows for which this expression returns true will be updated.