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COPY()				 SQL Commands				COPY()



NAME
       COPY - copy data between a file and a table


SYNOPSIS
       COPY tablename [ ( column [, ...] ) ]
	   FROM { 'filename' | STDIN }
	   [ [ WITH ]
		 [ BINARY ]
		 [ OIDS ]
		 [ DELIMITER [ AS ] 'delimiter' ]
		 [ NULL [ AS ] 'null string' ]
		 [ CSV [ HEADER ]
		       [ QUOTE [ AS ] 'quote' ]
		       [ ESCAPE [ AS ] 'escape' ]
		       [ FORCE NOT NULL column [, ...] ]

       COPY tablename [ ( column [, ...] ) ]
	   TO { 'filename' | STDOUT }
	   [ [ WITH ]
		 [ BINARY ]
		 [ OIDS ]
		 [ DELIMITER [ AS ] 'delimiter' ]
		 [ NULL [ AS ] 'null string' ]
		 [ CSV [ HEADER ]
		       [ QUOTE [ AS ] 'quote' ]
		       [ ESCAPE [ AS ] 'escape' ]
		       [ FORCE QUOTE column [, ...] ]


DESCRIPTION
       COPY  moves  data  between  PostgreSQL  tables and standard file-system
       files. COPY TO copies the contents of a table to	 a  file,  while  COPY
       FROM copies data from a file to a table (appending the data to whatever
       is in the table already).

       If a list of columns is specified, COPY will only copy the data in  the
       specified columns to or from the file.  If there are any columns in the
       table that are not in the  column  list,	 COPY  FROM  will  insert  the
       default values for those columns.

       COPY  with a file name instructs the PostgreSQL server to directly read
       from or write to a file. The file must be accessible to the server  and
       the name must be specified from the viewpoint of the server. When STDIN
       or STDOUT is specified, data is transmitted via the connection  between
       the client and the server.

PARAMETERS
       tablename
	      The name (optionally schema-qualified) of an existing table.

       column An  optional  list of columns to be copied. If no column list is
	      specified, all columns will be used.

       filename
	      The absolute path name of the  input  or	output	file.  Windows
	      users  might need to double backslashes used as path separators.

       STDIN  Specifies that input comes from the client application.

       STDOUT Specifies that output goes to the client application.

       BINARY Causes all data to be stored or read  in	binary	format	rather
	      than  as	text.  You  cannot specify the DELIMITER, NULL, or CSV
	      options in binary mode.

       OIDS   Specifies copying the OID for each row. (An error is  raised  if
	      OIDS is specified for a table that does not have OIDs.)

       delimiter
	      The  single  character  that  separates  columns within each row
	      (line) of the file. The default is a tab character in text mode,
	      a comma in CSV mode.

       null string
	      The  string  that	 represents  a	null  value. The default is \N
	      (backslash-N) in text mode, and a empty value with no quotes  in
	      CSV mode. You might prefer an empty string even in text mode for
	      cases where you don't  want  to  distinguish  nulls  from	 empty
	      strings.

	      Note:  When  using  COPY	FROM,  any data item that matches this
	      string will be stored as a null value, so you should  make  sure
	      that you use the same string as you used with COPY TO.


       CSV    Selects Comma Separated Value (CSV) mode.

       HEADER Specifies that the file contains a header line with the names of
	      each column in the file. On output, the first line contains  the
	      column  names  from  the	table, and on input, the first line is
	      ignored.

       quote  Specifies the quotation character in CSV mode.  The  default  is
	      double-quote.

       escape Specifies	 the  character that should appear before a QUOTE data
	      character value in CSV mode.  The default	 is  the  QUOTE	 value
	      (usually double-quote).

       FORCE QUOTE
	      In  CSV COPY TO mode, forces quoting to be used for all non-NULL
	      values in each specified column.	NULL output is never quoted.

       FORCE NOT NULL
	      In CSV COPY FROM mode, process each specified column  as	though
	      it  were quoted and hence not a NULL value. For the default null
	      string in CSV mode (''), this causes missing values to be	 input
	      as zero-length strings.

NOTES
       COPY can only be used with plain tables, not with views.

       The  BINARY key word causes all data to be stored/read as binary format
       rather than as text. It is somewhat faster than the normal  text	 mode,
       but  a binary-format file is less portable across machine architectures
       and PostgreSQL versions.

       You must have select privilege on the table whose values	 are  read  by
       COPY  TO,  and  insert  privilege  on  the  table into which values are
       inserted by COPY FROM.

       Files named in a COPY command are  read	or  written  directly  by  the
       server,	not  by the client application. Therefore, they must reside on
       or be accessible to the database server machine, not the	 client.  They
       must  be	 accessible to and readable or writable by the PostgreSQL user
       (the user ID the server runs as), not the client. COPY naming a file is
       only allowed to database superusers, since it allows reading or writing
       any file that the server has privileges to access.

       Do not confuse COPY with the psql instruction \copy. \copy invokes COPY
       FROM  STDIN  or	COPY  TO STDOUT, and then fetches/stores the data in a
       file accessible to the psql client. Thus, file accessibility and access
       rights  depend on the client rather than the server when \copy is used.

       It is recommended that the file name used in COPY always	 be  specified
       as an absolute path. This is enforced by the server in the case of COPY
       TO, but for COPY FROM you do have the option of	reading	 from  a  file
       specified  by a relative path. The path will be interpreted relative to
       the working directory of the server process (somewhere below  the  data
       directory), not the client's working directory.

       COPY  FROM will invoke any triggers and check constraints on the desti-
       nation table. However, it will not invoke rules.

       COPY input and output is affected by DateStyle. To  ensure  portability
       to  other PostgreSQL installations that might use non-default DateStyle
       settings, DateStyle should be set to ISO before using COPY TO.

       COPY stops operation at the first error. This should not lead to	 prob-
       lems  in the event of a COPY TO, but the target table will already have
       received earlier rows in a COPY FROM. These rows will not be visible or
       accessible, but they still occupy disk space. This may amount to a con-
       siderable amount of wasted disk space if the failure happened well into
       a  large	 copy  operation. You may wish to invoke VACUUM to recover the
       wasted space.

FILE FORMATS
   TEXT FORMAT
       When COPY is used without the BINARY or CSV options, the data  read  or
       written	is  a text file with one line per table row.  Columns in a row
       are separated by the delimiter character.  The column values themselves
       are  strings  generated	by  the	 output function, or acceptable to the
       input function, of each	attribute's  data  type.  The  specified  null
       string is used in place of columns that are null.  COPY FROM will raise
       an error if any line of the input file contains more or	fewer  columns
       than are expected.  If OIDS is specified, the OID is read or written as
       the first column, preceding the user data columns.

       End of data can be represented by a single line containing  just	 back-
       slash-period  (\.). An end-of-data marker is not necessary when reading
       from a file, since the end of file serves perfectly well; it is	needed
       only  when  copying  data  to or from client applications using pre-3.0
       client protocol.

       Backslash characters (\) may be used in the COPY	 data  to  quote  data
       characters  that	 might otherwise be taken as row or column delimiters.
       In particular, the following characters must be preceded by a backslash
       if  they	 appear	 as part of a column value: backslash itself, newline,
       carriage return, and the current delimiter character.

       The specified null string is sent by COPY TO without adding  any	 back-
       slashes;	 conversely,  COPY  FROM  matches  the	input against the null
       string before removing backslashes. Therefore, a null string such as \N
       cannot be confused with the actual data value \N (which would be repre-
       sented as \\N).

       The following special backslash sequences are recognized by COPY	 FROM:
       SequenceRepresents\bBackspace  (ASCII 8)\fForm feed (ASCII 12)\nNewline
       (ASCII 10)\rCarriage return (ASCII  13)\tTab  (ASCII  9)\vVertical  tab
       (ASCII 11)\digitsBackslash followed by one to three octal digits speci-
       fies the character with that numeric code\xdigitsBackslash  x  followed
       by one or two hex digits specifies the character with that numeric code
       Presently, COPY TO will never emit an  octal  or	 hex-digits  backslash
       sequence,  but  it  does use the other sequences listed above for those
       control characters.

       Any other backslashed character that is not mentioned in the above  ta-
       ble  will be taken to represent itself. However, beware of adding back-
       slashes unnecessarily, since that might accidentally produce  a	string
       matching	 the  end-of-data  marker  (\.)	 or  the  null	string	(\N by
       default). These strings will be recognized before any  other  backslash
       processing is done.

       It  is strongly recommended that applications generating COPY data con-
       vert data newlines and carriage returns to  the	\n  and	 \r  sequences
       respectively.  At  present  it is possible to represent a data carriage
       return by a backslash and carriage return, and to represent a data new-
       line  by a backslash and newline.  However, these representations might
       not be accepted in future releases.  They are also highly vulnerable to
       corruption  if  the  COPY file is transferred across different machines
       (for example, from Unix to Windows or vice versa).

       COPY TO will terminate each row with  a	Unix-style  newline  (''\n'').
       Servers	 running   on	Microsoft   Windows  instead  output  carriage
       return/newline (''\r\n''), but only for COPY to a server file; for con-
       sistency	 across	 platforms, COPY TO STDOUT always sends ''\n'' regard-
       less of server platform.	 COPY FROM can handle lines ending  with  new-
       lines,  carriage	 returns,  or  carriage return/newlines. To reduce the
       risk of error due to un-backslashed newlines or carriage	 returns  that
       were  meant as data, COPY FROM will complain if the line endings in the
       input are not all alike.

   CSV FORMAT
       This format is used for importing and  exporting	 the  Comma  Separated
       Value  (CSV)  file  format used by many other programs, such as spread-
       sheets. Instead of the escaping	used  by  PostgreSQL's	standard  text
       mode, it produces and recognizes the common CSV escaping mechanism.

       The  values in each record are separated by the DELIMITER character. If
       the value contains the delimiter character, the	QUOTE  character,  the
       NULL  string, a carriage return, or line feed character, then the whole
       value is prefixed and suffixed by the QUOTE character, and  any	occur-
       rence  within the value of a QUOTE character or the ESCAPE character is
       preceded by the escape character.  You can  also	 use  FORCE  QUOTE  to
       force quotes when outputting non-NULL values in specific columns.

       The  CSV format has no standard way to distinguish a NULL value from an
       empty string.  PostgreSQL's COPY handles this by	 quoting.  A  NULL  is
       output  as the NULL string and is not quoted, while a data value match-
       ing the NULL string is quoted. Therefore, using the default settings, a
       NULL  is	 written as an unquoted empty string, while an empty string is
       written with double quotes (""). Reading values follows similar	rules.
       You  can	 use FORCE NOT NULL to prevent NULL input comparisons for spe-
       cific columns.

       Because backslash is not a special character in the CSV format, \., the
       end-of-data  marker,  could  also  appear as a data value. To avoid any
       misinterpretation, a \.	data value appearing as a lone entry on a line
       is  automatically  quoted  on  output,  and on input, if quoted, is not
       interpreted as the end-of-data marker. If you are loading a  file  cre-
       ated by another application that has a single unquoted column and might
       have a value of \., you might need to quote that	 value	in  the	 input
       file.

	      Note:  In	 CSV  mode,  all  characters are significant. A quoted
	      value surrounded by white space, or any  characters  other  than
	      DELIMITER,  will include those characters. This can cause errors
	      if you import data from a system that pads CSV lines with	 white
	      space  out  to  some fixed width. If such a situation arises you
	      might need to preprocess the CSV file  to	 remove	 the  trailing
	      white space, before importing the data into PostgreSQL.


	      Note:  CSV  mode	will both recognize and produce CSV files with
	      quoted values containing	embedded  carriage  returns  and  line
	      feeds.  Thus  the	 files are not strictly one line per table row
	      like text-mode files.


	      Note: Many programs produce strange  and	occasionally  perverse
	      CSV  files, so the file format is more a convention than a stan-
	      dard. Thus  you  might  encounter	 some  files  that  cannot  be
	      imported using this mechanism, and COPY might produce files that
	      other programs cannot process.


   BINARY FORMAT
       The file format used for COPY BINARY changed in PostgreSQL 7.4. The new
       format  consists	 of  a file header, zero or more tuples containing the
       row data, and a file trailer. Headers and data are now in network  byte
       order.

   FILE HEADER
       The  file  header  consists  of 15 bytes of fixed fields, followed by a
       variable-length header extension area. The fixed fields are:

       Signature
	      11-byte sequence PGCOPY\n\377\r\n\0 -- note that the zero byte is
	      a	 required part of the signature. (The signature is designed to
	      allow easy identification of files that have been	 munged	 by  a
	      non-8-bit-clean transfer. This signature will be changed by end-
	      of-line-translation filters, dropped zero	 bytes,	 dropped  high
	      bits, or parity changes.)

       Flags field
	      32-bit  integer bit mask to denote important aspects of the file
	      format. Bits are numbered from 0 (LSB) to 31  (MSB).  Note  that
	      this  field  is  stored  in network byte order (most significant
	      byte first), as are all the integer fields used in the file for-
	      mat.  Bits  16-31	 are  reserved	to denote critical file format
	      issues; a reader should abort if it finds an unexpected bit  set
	      in  this	range. Bits 0-15 are reserved to signal backwards-com-
	      patible format issues; a reader should simply ignore  any	 unex-
	      pected  bits  set	 in this range. Currently only one flag bit is
	      defined, and the rest must be zero:

	      Bit 16 if 1, OIDs are included in the data; if 0, not


       Header extension area length
	      32-bit integer, length in bytes  of  remainder  of  header,  not
	      including	 self.	 Currently,  this is zero, and the first tuple
	      follows immediately. Future changes to the  format  might	 allow
	      additional  data	to  be	present in the header. A reader should
	      silently skip over any header extension data it  does  not  know
	      what to do with.


       The  header extension area is envisioned to contain a sequence of self-
       identifying chunks. The flags field is not  intended  to	 tell  readers
       what is in the extension area. Specific design of header extension con-
       tents is left for a later release.

       This design allows for both backwards-compatible header additions  (add
       header extension chunks, or set low-order flag bits) and non-backwards-
       compatible changes (set high-order flag bits to	signal	such  changes,
       and add supporting data to the extension area if needed).

   TUPLES
       Each  tuple  begins with a 16-bit integer count of the number of fields
       in the tuple. (Presently, all tuples in a  table	 will  have  the  same
       count,  but  that  might	 not  always be true.) Then, repeated for each
       field in the tuple, there is a 32-bit length word followed by that many
       bytes  of field data. (The length word does not include itself, and can
       be zero.) As a special case, -1 indicates a NULL field value. No	 value
       bytes follow in the NULL case.

       There is no alignment padding or any other extra data between fields.

       Presently,  all	data values in a COPY BINARY file are assumed to be in
       binary format (format code one). It is anticipated that a future exten-
       sion  may  add a header field that allows per-column format codes to be
       specified.

       To determine the appropriate binary format for the  actual  tuple  data
       you  should  consult the PostgreSQL source, in particular the *send and
       *recv functions for each column's data type (typically these  functions
       are found in the src/backend/utils/adt/ directory of the source distri-
       bution).

       If OIDs are included in the file, the OID field immediately follows the
       field-count word. It is a normal field except that it's not included in
       the field-count. In particular it has a length word -- this  will  allow
       handling	 of  4-byte  vs.  8-byte  OIDs without too much pain, and will
       allow OIDs to be shown as null if that ever proves desirable.

   FILE TRAILER
       The file trailer consists of a 16-bit integer word containing -1.  This
       is easily distinguished from a tuple's field-count word.

       A reader should report an error if a field-count word is neither -1 nor
       the expected number of columns. This provides an	 extra	check  against
       somehow getting out of sync with the data.

EXAMPLES
       The  following  example copies a table to the client using the vertical
       bar (|) as the field delimiter:

       COPY country TO STDOUT WITH DELIMITER '|';


       To copy data from a file into the country table:

       COPY country FROM '/usr1/proj/bray/sql/country_data';


       To copy into a file just the countries whose names start with 'A' using
       a temporary table which is automatically deleted:

       BEGIN;
       CREATE TEMP TABLE a_list_countries AS
	   SELECT * FROM country WHERE country_name LIKE 'A%';
       COPY a_list_countries TO '/usr1/proj/bray/sql/a_list_countries.copy';
       ROLLBACK;


       Here is a sample of data suitable for copying into a table from STDIN:

       AF      AFGHANISTAN
       AL      ALBANIA
       DZ      ALGERIA
       ZM      ZAMBIA
       ZW      ZIMBABWE

       Note that the white space on each line is actually a tab character.

       The  following  is the same data, output in binary format.  The data is
       shown after filtering through the Unix utility od  -c.  The  table  has
       three  columns;	the  first has type char(2), the second has type text,
       and the third has type integer. All the rows have a null value  in  the
       third column.

       0000000	 P   G	 C   O	 P   Y	\n 377	\r  \n	\0  \0	\0  \0	\0  \0
       0000020	\0  \0	\0  \0 003  \0	\0  \0 002   A	 F  \0	\0  \0 013   A
       0000040	 F   G	 H   A	 N   I	 S   T	 A   N 377 377 377 377	\0 003
       0000060	\0  \0	\0 002	 A   L	\0  \0	\0 007	 A   L	 B   A	 N   I
       0000100	 A 377 377 377 377  \0 003  \0	\0  \0 002   D	 Z  \0	\0  \0
       0000120 007   A	 L   G	 E   R	 I   A 377 377 377 377	\0 003	\0  \0
       0000140	\0 002	 Z   M	\0  \0	\0 006	 Z   A	 M   B	 I   A 377 377
       0000160 377 377	\0 003	\0  \0	\0 002	 Z   W	\0  \0	\0  \b	 Z   I
       0000200	 M   B	 A   B	 W   E 377 377 377 377 377 377


COMPATIBILITY
       There is no COPY statement in the SQL standard.

       The  following  syntax  was  used  before PostgreSQL version 7.3 and is
       still supported:

       COPY [ BINARY ] tablename [ WITH OIDS ]
	   FROM { 'filename' | STDIN }
	   [ [USING] DELIMITERS 'delimiter' ]
	   [ WITH NULL AS 'null string' ]

       COPY [ BINARY ] tablename [ WITH OIDS ]
	   TO { 'filename' | STDOUT }
	   [ [USING] DELIMITERS 'delimiter' ]
	   [ WITH NULL AS 'null string' ]




SQL - Language Statements	  2010-12-14				COPY()
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