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CREATE TABLE()			 SQL Commands			CREATE TABLE()

NAME
       CREATE TABLE - define a new table

SYNOPSIS
       CREATE [ [ GLOBAL | LOCAL ] { TEMPORARY | TEMP } ] TABLE table_name ( [
	 { column_name data_type [ DEFAULT default_expr ] [ column_constraint [ ... ] ]
	   | table_constraint
	   | LIKE parent_table [ { INCLUDING | EXCLUDING } DEFAULTS ] }
	   [, ... ]
       ] )
       [ INHERITS ( parent_table [, ... ] ) ]
       [ WITH OIDS | WITHOUT OIDS ]
       [ ON COMMIT { PRESERVE ROWS | DELETE ROWS | DROP } ]
       [ TABLESPACE tablespace ]

       where column_constraint is:

       [ CONSTRAINT constraint_name ]
       { NOT NULL |
	 NULL |
	 UNIQUE [ USING INDEX TABLESPACE tablespace ] |
	 PRIMARY KEY [ USING INDEX TABLESPACE tablespace ] |
	 CHECK (expression) |
	 REFERENCES reftable [ ( refcolumn ) ] [ MATCH FULL | MATCH PARTIAL | MATCH SIMPLE ]
	   [ ON DELETE action ] [ ON UPDATE action ] }
       [ DEFERRABLE | NOT DEFERRABLE ] [ INITIALLY DEFERRED | INITIALLY IMMEDIATE ]

       and table_constraint is:

       [ CONSTRAINT constraint_name ]
       { UNIQUE ( column_name [, ... ] ) [ USING INDEX TABLESPACE tablespace ] |
	 PRIMARY KEY ( column_name [, ... ] ) [ USING INDEX TABLESPACE tablespace ] |
	 CHECK ( expression ) |
	 FOREIGN KEY ( column_name [, ... ] ) REFERENCES reftable [ ( refcolumn [, ... ] ) ]
	   [ MATCH FULL | MATCH PARTIAL | MATCH SIMPLE ] [ ON DELETE action ] [ ON UPDATE action ] }
       [ DEFERRABLE | NOT DEFERRABLE ] [ INITIALLY DEFERRED | INITIALLY IMMEDIATE ]

DESCRIPTION
       CREATE  TABLE  will  create a new, initially empty table in the current
       database. The table will be owned by the user issuing the command.

       If a schema name is given (for example, CREATE  TABLE  myschema.mytable
       ...) then the table is created in the specified schema. Otherwise it is
       created in the current schema. Temporary	 tables	 exist	in  a  special
       schema, so a schema name may not be given when creating a temporary ta‐
       ble. The name of the table must be distinct from the name of any	 other
       table, sequence, index, or view in the same schema.

       CREATE TABLE also automatically creates a data type that represents the
       composite type corresponding to one row of the table. Therefore, tables
       cannot have the same name as any existing data type in the same schema.

       The optional constraint clauses specify constraints (tests) that new or
       updated rows must satisfy for an insert or update operation to succeed.
       A constraint is an SQL object that helps define the set of valid values
       in the table in various ways.

       There are two ways to define constraints: table constraints and	column
       constraints. A column constraint is defined as part of a column defini‐
       tion. A table constraint definition is not tied to a particular column,
       and it can encompass more than one column.  Every column constraint can
       also be written as a table constraint; a column constraint  is  only  a
       notational  convenience	for  use  when the constraint only affects one
       column.

PARAMETERS
       TEMPORARY or TEMP
	      If specified, the table is created as a temporary table.	Tempo‐
	      rary  tables  are automatically dropped at the end of a session,
	      or optionally at the end of the current transaction (see ON COM‐
	      MIT below). Existing permanent tables with the same name are not
	      visible to the current session while the temporary table exists,
	      unless  they  are	 referenced  with  schema-qualified names. Any
	      indexes created on a temporary table are automatically temporary
	      as well.

	      Optionally,  GLOBAL  or LOCAL can be written before TEMPORARY or
	      TEMP.  This makes no difference in PostgreSQL, but see  Compati‐
	      bility [create_table(7)].

       table_name
	      The  name	 (optionally schema-qualified) of the table to be cre‐
	      ated.

       column_name
	      The name of a column to be created in the new table.

       data_type
	      The data type of the column. This may include array  specifiers.
	      For  more information on the data types supported by PostgreSQL,
	      refer to the documentation.

       DEFAULT
	      The DEFAULT clause assigns a default data value for  the	column
	      whose  column  definition	 it  appears  within. The value is any
	      variable-free expression	(subqueries  and  cross-references  to
	      other  columns  in  the current table are not allowed). The data
	      type of the default expression must match the data type  of  the
	      column.

	      The default expression will be used in any insert operation that
	      does not specify a value for the column. If there is no  default
	      for a column, then the default is null.

       INHERITS ( parent_table [, ... ] )
	      The  optional  INHERITS  clause  specifies a list of tables from
	      which the new table automatically inherits all columns.

	      Use of INHERITS creates a persistent  relationship  between  the
	      new child table and its parent table(s). Schema modifications to
	      the parent(s) normally propagate to children  as	well,  and  by
	      default  the data of the child table is included in scans of the
	      parent(s).

	      If the same column name exists in more than one parent table, an
	      error  is reported unless the data types of the columns match in
	      each of the parent tables. If there is  no  conflict,  then  the
	      duplicate	 columns are merged to form a single column in the new
	      table. If the column name list of the new table contains a  col‐
	      umn  name	 that  is  also inherited, the data type must likewise
	      match the inherited column(s), and the  column  definitions  are
	      merged  into one. However, inherited and new column declarations
	      of the same name need not	 specify  identical  constraints:  all
	      constraints  provided  from  any declaration are merged together
	      and all are applied to the new table. If the new	table  explic‐
	      itly  specifies  a  default  value  for the column, this default
	      overrides any defaults from inherited declarations of  the  col‐
	      umn.  Otherwise, any parents that specify default values for the
	      column must all specify the same default, or an  error  will  be
	      reported.

       LIKE parent_table [ { INCLUDING | EXCLUDING } DEFAULTS ]
	      The LIKE clause specifies a table from which the new table auto‐
	      matically copies all column names, their data types,  and	 their
	      not-null constraints.

	      Unlike INHERITS, the new table and original table are completely
	      decoupled after creation is complete. Changes  to	 the  original
	      table will not be applied to the new table, and it is not possi‐
	      ble to include data of the new table in scans  of	 the  original
	      table.

	      Default  expressions for the copied column definitions will only
	      be copied if INCLUDING DEFAULTS is specified. The default behav‐
	      ior  is to exclude default expressions, resulting in all columns
	      of the new table having null defaults.

       WITH OIDS

       WITHOUT OIDS
	      This optional clause specifies whether rows  of  the  new	 table
	      should  have OIDs (object identifiers) assigned to them. If nei‐
	      ther WITH OIDS nor WITHOUT OIDS is specified, the default	 value
	      depends  upon the default_with_oids configuration parameter. (If
	      the new table inherits from any tables that have OIDs, then WITH
	      OIDS is forced even if the command says WITHOUT OIDS.)

	      If  WITHOUT OIDS is specified or implied, the new table does not
	      store OIDs and no OID will be assigned for a row	inserted  into
	      it.  This	 is  generally	considered  worthwhile,	 since it will
	      reduce OID consumption and thereby postpone  the	wraparound  of
	      the  32-bit OID counter. Once the counter wraps around, OIDs can
	      no longer be assumed to be unique, which makes them considerably
	      less  useful.  In	 addition, excluding OIDs from a table reduces
	      the space required to store the table on disk by 4 bytes per row
	      (on most machines), slightly improving performance.

	      To remove OIDs from a table after it has been created, use ALTER
	      TABLE [alter_table(7)].

       CONSTRAINT constraint_name
	      An optional name for a column or table constraint. If not speci‐
	      fied, the system generates a name.

       NOT NULL
	      The column is not allowed to contain null values.

       NULL   The  column  is  allowed	to  contain  null  values. This is the
	      default.

	      This clause is only provided for compatibility with non-standard
	      SQL databases. Its use is discouraged in new applications.

       UNIQUE (column constraint)

       UNIQUE ( column_name [, ... ] ) (table constraint)
	      The UNIQUE constraint specifies that a group of one or more col‐
	      umns of a table may contain only unique values. The behavior  of
	      the  unique table constraint is the same as that for column con‐
	      straints, with the additional capability to span	multiple  col‐
	      umns.

	      For the purpose of a unique constraint, null values are not con‐
	      sidered equal.

	      Each unique table constraint must name a set of columns that  is
	      different	 from  the set of columns named by any other unique or
	      primary key constraint defined  for  the	table.	(Otherwise  it
	      would just be the same constraint listed twice.)

       PRIMARY KEY (column constraint)

       PRIMARY KEY ( column_name [, ... ] ) (table constraint)
	      The primary key constraint specifies that a column or columns of
	      a table may contain only unique (non-duplicate), nonnull values.
	      Technically,  PRIMARY  KEY is merely a combination of UNIQUE and
	      NOT NULL, but identifying a set of columns as primary  key  also
	      provides	metadata  about the design of the schema, as a primary
	      key implies that other tables may rely on this set of columns as
	      a unique identifier for rows.

	      Only  one primary key can be specified for a table, whether as a
	      column constraint or a table constraint.

	      The primary key constraint should name a set of columns that  is
	      different	 from  other  sets of columns named by any unique con‐
	      straint defined for the same table.

       CHECK (expression)
	      The CHECK clause specifies an  expression	 producing  a  Boolean
	      result  which  new or updated rows must satisfy for an insert or
	      update operation to succeed. Expressions evaluating to  TRUE  or
	      UNKNOWN succeed. Should any row of an insert or update operation
	      produce a FALSE result an error  exception  is  raised  and  the
	      insert or update does not alter the database. A check constraint
	      specified as a column constraint should reference that  column's
	      value  only, while an expression appearing in a table constraint
	      may reference multiple columns.

	      Currently, CHECK expressions cannot contain subqueries nor refer
	      to variables other than columns of the current row.

       REFERENCES  reftable  [ ( refcolumn ) ] [ MATCH matchtype ] [ ON DELETE
       action ] [ ON UPDATE action ] (column constraint)

       FOREIGN KEY ( column [, ... ] )
	      These clauses specify a foreign key constraint,  which  requires
	      that  a  group of one or more columns of the new table must only
	      contain values that match values in the referenced column(s)  of
	      some  row	 of the referenced table. If refcolumn is omitted, the
	      primary key of the reftable is used. The referenced columns must
	      be the columns of a unique or primary key constraint in the ref‐
	      erenced table. Note that foreign	key  constraints  may  not  be
	      defined between temporary tables and permanent tables.

	      A	 value	inserted  into	the  referencing  column(s) is matched
	      against the values of the referenced table and  referenced  col‐
	      umns  using  the	given match type. There are three match types:
	      MATCH FULL, MATCH PARTIAL, and MATCH SIMPLE, which is  also  the
	      default.	MATCH  FULL will not allow one column of a multicolumn
	      foreign key to be null unless all foreign key columns are	 null.
	      MATCH  SIMPLE  allows  some foreign key columns to be null while
	      other parts of the foreign key are not null.  MATCH  PARTIAL  is
	      not yet implemented.

	      In addition, when the data in the referenced columns is changed,
	      certain actions are performed on the data in this	 table's  col‐
	      umns.  The ON DELETE clause specifies the action to perform when
	      a referenced row in the referenced table is being deleted. Like‐
	      wise,  the ON UPDATE clause specifies the action to perform when
	      a referenced column in the referenced table is being updated  to
	      a new value. If the row is updated, but the referenced column is
	      not actually changed, no action  is  done.  Referential  actions
	      other  than  the NO ACTION check cannot be deferred, even if the
	      constraint is declared deferrable. There are the following  pos‐
	      sible actions for each clause:

	      NO ACTION
		     Produce  an  error indicating that the deletion or update
		     would create a foreign key constraint violation.  If  the
		     constraint	 is  deferred,	this error will be produced at
		     constraint check time if there still exist any  referenc‐
		     ing rows. This is the default action.

	      RESTRICT
		     Produce  an  error indicating that the deletion or update
		     would create a foreign key constraint violation.  This is
		     the  same	as  NO	ACTION	except	that  the check is not
		     deferrable.

	      CASCADE
		     Delete any rows referencing the deleted  row,  or	update
		     the  value	 of the referencing column to the new value of
		     the referenced column, respectively.

	      SET NULL
		     Set the referencing column(s) to null.

	      SET DEFAULT
		     Set the referencing column(s) to their default values.

       If the referenced column(s) are changed frequently, it may be  wise  to
       add  an	index  to  the	foreign key column so that referential actions
       associated with the foreign key column  can  be	performed  more	 effi‐
       ciently.

       DEFERRABLE

       NOT DEFERRABLE
	      This  controls  whether  the  constraint can be deferred. A con‐
	      straint that is not deferrable will be checked immediately after
	      every  command.  Checking of constraints that are deferrable may
	      be postponed until the end of the	 transaction  (using  the  SET
	      CONSTRAINTS  [set_constraints(7)]	 command).   NOT DEFERRABLE is
	      the default. Only foreign key constraints currently accept  this
	      clause. All other constraint types are not deferrable.

       INITIALLY IMMEDIATE

       INITIALLY DEFERRED
	      If a constraint is deferrable, this clause specifies the default
	      time to check the constraint. If	the  constraint	 is  INITIALLY
	      IMMEDIATE,  it  is  checked  after  each	statement. This is the
	      default. If the constraint is INITIALLY DEFERRED, it is  checked
	      only  at	the  end of the transaction. The constraint check time
	      can be altered with  the	SET  CONSTRAINTS  [set_constraints(7)]
	      command.

       ON COMMIT
	      The  behavior  of	 temporary  tables at the end of a transaction
	      block can be controlled using ON COMMIT.	The three options are:

	      PRESERVE ROWS
		     No special action is taken at the ends  of	 transactions.
		     This is the default behavior.

	      DELETE ROWS
		     All  rows	in  the temporary table will be deleted at the
		     end of each transaction block. Essentially, an  automatic
		     truncate(7) is done at each commit.

	      DROP   The  temporary  table  will  be dropped at the end of the
		     current transaction block.

       TABLESPACE tablespace
	      The tablespace is the name of the tablespace in  which  the  new
	      table is to be created.  If not specified, default_tablespace is
	      used, or the database's default tablespace if default_tablespace
	      is an empty string.

       USING INDEX TABLESPACE tablespace
	      This  clause  allows  selection  of  the tablespace in which the
	      index associated with a UNIQUE or PRIMARY KEY constraint will be
	      created.	 If  not specified, default_tablespace is used, or the
	      database's default tablespace if default_tablespace is an	 empty
	      string.

NOTES
       Using  OIDs  in	new  applications  is not recommended: where possible,
       using a SERIAL or other sequence generator as the table's  primary  key
       is  preferred.  However,	 if  your application does make use of OIDs to
       identify specific rows of a table, it is recommended to create a unique
       constraint  on the oid column of that table, to ensure that OIDs in the
       table will indeed uniquely identify rows even after counter wraparound.
       Avoid  assuming that OIDs are unique across tables; if you need a data‐
       base-wide unique identifier, use the combination of  tableoid  and  row
       OID for the purpose.

	      Tip:  The use of WITHOUT OIDS is not recommended for tables with
	      no primary key, since without either an OID  or  a  unique  data
	      key, it is difficult to identify specific rows.

       PostgreSQL  automatically  creates  an index for each unique constraint
       and primary key constraint to enforce uniqueness. Thus, it is not  nec‐
       essary to create an index explicitly for primary key columns. (See CRE‐
       ATE INDEX [create_index(7)] for more information.)

       Unique constraints and primary keys are not inherited  in  the  current
       implementation.	This  makes  the combination of inheritance and unique
       constraints rather dysfunctional.

       A table cannot have more than 1600 columns. (In practice, the effective
       limit is lower because of tuple-length constraints.)

EXAMPLES
       Create table films and table distributors:

       CREATE TABLE films (
	   code	       char(5) CONSTRAINT firstkey PRIMARY KEY,
	   title       varchar(40) NOT NULL,
	   did	       integer NOT NULL,
	   date_prod   date,
	   kind	       varchar(10),
	   len	       interval hour to minute
       );

       CREATE TABLE distributors (
	    did	   integer PRIMARY KEY DEFAULT nextval('serial'),
	    name   varchar(40) NOT NULL CHECK (name <> '')
       );

       Create a table with a 2-dimensional array:

       CREATE TABLE array_int (
	   vector  int[][]
       );

       Define a unique table constraint for the table films. Unique table con‐
       straints can be defined on one or more columns of the table.

       CREATE TABLE films (
	   code	       char(5),
	   title       varchar(40),
	   did	       integer,
	   date_prod   date,
	   kind	       varchar(10),
	   len	       interval hour to minute,
	   CONSTRAINT production UNIQUE(date_prod)
       );

       Define a check column constraint:

       CREATE TABLE distributors (
	   did	   integer CHECK (did > 100),
	   name	   varchar(40)
       );

       Define a check table constraint:

       CREATE TABLE distributors (
	   did	   integer,
	   name	   varchar(40)
	   CONSTRAINT con1 CHECK (did > 100 AND name <> '')
       );

       Define a primary key table constraint for the table films. Primary  key
       table constraints can be defined on one or more columns of the table.

       CREATE TABLE films (
	   code	       char(5),
	   title       varchar(40),
	   did	       integer,
	   date_prod   date,
	   kind	       varchar(10),
	   len	       interval hour to minute,
	   CONSTRAINT code_title PRIMARY KEY(code,title)
       );

       Define  a  primary key constraint for table distributors. The following
       two examples are equivalent, the first using the table constraint  syn‐
       tax, the second the column constraint syntax.

       CREATE TABLE distributors (
	   did	   integer,
	   name	   varchar(40),
	   PRIMARY KEY(did)
       );

       CREATE TABLE distributors (
	   did	   integer PRIMARY KEY,
	   name	   varchar(40)
       );

       This  assigns  a	 literal  constant  default value for the column name,
       arranges for the default value of column did to be generated by select‐
       ing the next value of a sequence object, and makes the default value of
       modtime be the time at which the row is inserted.

       CREATE TABLE distributors (
	   name	     varchar(40) DEFAULT 'Luso Films',
	   did	     integer DEFAULT nextval('distributors_serial'),
	   modtime   timestamp DEFAULT current_timestamp
       );

       Define two NOT NULL column constraints on the table  distributors,  one
       of which is explicitly given a name:

       CREATE TABLE distributors (
	   did	   integer CONSTRAINT no_null NOT NULL,
	   name	   varchar(40) NOT NULL
       );

       Define a unique constraint for the name column:

       CREATE TABLE distributors (
	   did	   integer,
	   name	   varchar(40) UNIQUE
       );

       The  above  is  equivalent  to  the following specified as a table con‐
       straint:

       CREATE TABLE distributors (
	   did	   integer,
	   name	   varchar(40),
	   UNIQUE(name)
       );

       Create table cinemas in tablespace diskvol1:

       CREATE TABLE cinemas (
	       id serial,
	       name text,
	       location text
       ) TABLESPACE diskvol1;

COMPATIBILITY
       The CREATE TABLE command conforms to the SQL standard, with  exceptions
       listed below.

   TEMPORARY TABLES
       Although the syntax of CREATE TEMPORARY TABLE resembles that of the SQL
       standard, the effect is not the same. In the standard, temporary tables
       are defined just once and automatically exist (starting with empty con‐
       tents) in every session that needs them.	 PostgreSQL  instead  requires
       each  session  to issue its own CREATE TEMPORARY TABLE command for each
       temporary table to be used. This allows different sessions to  use  the
       same  temporary	table  name  for different purposes, whereas the stan‐
       dard's approach constrains all instances of  a  given  temporary	 table
       name to have the same table structure.

       The standard's definition of the behavior of temporary tables is widely
       ignored. PostgreSQL's behavior on this point is similar to that of sev‐
       eral other SQL databases.

       The standard's distinction between global and local temporary tables is
       not in PostgreSQL, since that distinction depends  on  the  concept  of
       modules,	 which	PostgreSQL  does  not have.  For compatibility's sake,
       PostgreSQL will accept the GLOBAL and LOCAL keywords in a temporary ta‐
       ble declaration, but they have no effect.

       The  ON COMMIT clause for temporary tables also resembles the SQL stan‐
       dard, but has some differences.	If the ON COMMIT  clause  is  omitted,
       SQL  specifies that the default behavior is ON COMMIT DELETE ROWS. How‐
       ever, the default behavior in PostgreSQL is ON  COMMIT  PRESERVE	 ROWS.
       The ON COMMIT DROP option does not exist in SQL.

   COLUMN CHECK CONSTRAINTS
       The  SQL	 standard says that CHECK column constraints may only refer to
       the column they apply to; only CHECK table  constraints	may  refer  to
       multiple	 columns.   PostgreSQL	does  not enforce this restriction; it
       treats column and table check constraints alike.

   NULL ``CONSTRAINT''
       The NULL ``constraint'' (actually a  non-constraint)  is	 a  PostgreSQL
       extension  to  the SQL standard that is included for compatibility with
       some other database systems (and for symmetry with the  NOT  NULL  con‐
       straint).  Since it is the default for any column, its presence is sim‐
       ply noise.

   INHERITANCE
       Multiple inheritance via the INHERITS clause is a  PostgreSQL  language
       extension.   SQL:1999  and later define single inheritance using a dif‐
       ferent syntax and different semantics.  SQL:1999-style  inheritance  is
       not yet supported by PostgreSQL.

   OBJECT IDS
       The PostgreSQL concept of OIDs is not standard.

   ZERO-COLUMN TABLES
       PostgreSQL  allows  a  table  of no columns to be created (for example,
       CREATE TABLE foo();). This is an extension from the SQL standard, which
       does  not allow zero-column tables. Zero-column tables are not in them‐
       selves very useful, but disallowing them creates odd special cases  for
       ALTER  TABLE  DROP  COLUMN,  so	it  seems  cleaner to ignore this spec
       restriction.

   TABLESPACES
       The PostgreSQL concept of tablespaces is	 not  part  of	the  standard.
       Hence,  the  clauses  TABLESPACE	 and USING INDEX TABLESPACE are exten‐
       sions.

SEE ALSO
       ALTER  TABLE  [alter_table(7)],	DROP  TABLE  [drop_table(l)],	CREATE
       TABLESPACE [create_tablespace(l)]

SQL - Language Statements	  2005-11-05			CREATE TABLE()
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