Index for Section TABLE

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ALTER
NAME
  ALTER TABLE - change the definition of a table

SYNOPSIS
  ALTER TABLE [ ONLY ] table [ * ]
      ADD [ COLUMN ] column type [ column_constraint [ ... ] ]
  ALTER TABLE [ ONLY ] table [ * ]
      ALTER [ COLUMN ] column { SET DEFAULT value | DROP DEFAULT }
  ALTER TABLE [ ONLY ] table [ * ]
      ALTER [ COLUMN ] column SET STATISTICS integer
  ALTER TABLE [ ONLY ] table [ * ]
      RENAME [ COLUMN ] column TO newcolumn
  ALTER TABLE table
      RENAME TO new_table
  ALTER TABLE table
      ADD table_constraint_definition
  ALTER TABLE [ ONLY ] table
	  DROP CONSTRAINT constraint { RESTRICT | CASCADE }
  ALTER TABLE table
	  OWNER TO new_owner

  INPUTS

  table
       The name of an existing table to alter.

  column
       Name of a new or existing column.

  type
       Type of the new column.

  newcolumn
       New name for an existing column.

  new_table
       New name for the table.

  table_constraint_definition
       New table constraint for the table

  new_owner
       The user name of the new owner of the table.

  OUTPUTS

  ALTER
       Message returned from column or table renaming.

  ERROR
       Message returned if table or column is not available.

DESCRIPTION
  ALTER TABLE changes the definition of an existing table.  The ADD COLUMN
  form adds a new column to the table using the same syntax as CREATE TABLE
  [create_table(5)].  The ALTER COLUMN SET/DROP DEFAULT forms allow you to
  set or remove the default for the column. Note that defaults only apply to
  subsequent INSERT commands; they do not cause rows already in the table to
  change.  The ALTER COLUMN SET STATISTICS form allows you to set the
  statistics-gathering target for subsequent ANALYZE [analyze(5)] operations.
  The RENAME clause causes the name of a table, column, index, or sequence to
  change without changing any of the data. The data will remain of the same
  type and size after the command is executed.	The ADD
  table_constraint_definition clause adds a new constraint to the table using
  the same syntax as CREATE TABLE [create_table(5)]. The DROP CONSTRAINT
  constraint clause drops all constraints on the table (and its children)
  that match constraint.  The OWNER clause changes the owner of the table to
  the user  new user.

  You must own the table in order to change its schema.

  NOTES

  The keyword COLUMN is noise and can be omitted.

  In the current implementation of ADD COLUMN, default and NOT NULL clauses
  for the new column are not supported.	 You can use the SET DEFAULT form of
  ALTER TABLE to set the default later.	 (You may also want to update the
  already existing rows to the new default value, using UPDATE [update(5)].)

  In DROP CONSTRAINT, the RESTRICT keyword is required, although dependencies
  are not yet checked. The CASCADE option is unsupported. Currently DROP
  CONSTRAINT drops only CHECK constraints.  To remove a PRIMARY or UNIQUE
  constraint, drop the relevant index using the DROP INDEX [drop_index(5)]
  command.  To remove FOREIGN KEY constraints you need to recreate and reload
  the table, using other parameters to the CREATE TABLE [create_table(5)]
  command.

  For example, to drop all constraints on a table distributors:

  CREATE TABLE temp AS SELECT * FROM distributors;
  DROP TABLE distributors;
  CREATE TABLE distributors AS SELECT * FROM temp;
  DROP TABLE temp;

  You must own the table in order to change it.	 Changing any part of the
  schema of a system catalog is not permitted.	The PostgreSQL User's Guide
  has further information on inheritance.

  Refer to CREATE TABLE for a further description of valid arguments.

USAGE
  To add a column of type varchar to a table:

  ALTER TABLE distributors ADD COLUMN address VARCHAR(30);

  To rename an existing column:

  ALTER TABLE distributors RENAME COLUMN address TO city;

  To rename an existing table:

  ALTER TABLE distributors RENAME TO suppliers;

  To add a check constraint to a table:

  ALTER TABLE distributors ADD CONSTRAINT zipchk CHECK (char_length(zipcode) = 5);

  To remove a check constraint from a table and all its children:

  ALTER TABLE distributors DROP CONSTRAINT zipchk RESTRICT;

  To add a foreign key constraint to a table:

  ALTER TABLE distributors ADD CONSTRAINT distfk FOREIGN KEY (address) REFERENCES addresses(address) MATCH FULL;

  To add a (multicolumn) unique constraint to a table:

  ALTER TABLE distributors ADD CONSTRAINT dist_id_zipcode_key UNIQUE (dist_id, zipcode);

  To add an automatically named primary key constraint to a table, noting
  that a table can only ever have one primary key:

  ALTER TABLE distributors ADD PRIMARY KEY (dist_id);

COMPATIBILITY
  SQL92

  The ADD COLUMN form is compliant with the exception that it does not
  support defaults and NOT NULL constraints, as explained above.  The ALTER
  COLUMN form is in full compliance.

  SQL92 specifies some additional capabilities for ALTER TABLE statement
  which are not yet directly supported by PostgreSQL:

  .sp  Removes a column from a table.  Currently, to remove an existing
       column the table must be recreated and reloaded:

       CREATE TABLE temp AS SELECT did, city FROM distributors;
       DROP TABLE distributors;
       CREATE TABLE distributors (
	   did	    DECIMAL(3)	DEFAULT 1,
	   name	    VARCHAR(40) NOT NULL
       );
       INSERT INTO distributors SELECT * FROM temp;
       DROP TABLE temp;

  The clauses to rename tables, columns, indexes, and sequences are
  PostgreSQL extensions from SQL92.

Index for Section TABLE

Alphabetical listing for A

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