1COPY(7) PostgreSQL 9.2.24 Documentation COPY(7)
2
6 COPY - copy data between a file and a table
7
9 COPY table_name [ ( column_name [, ...] ) ]
10 FROM { 'filename' | STDIN }
11 [ [ WITH ] ( option [, ...] ) ]
12 COPY { table_name [ ( column_name [, ...] ) ] | ( query ) }
14 TO { 'filename' | STDOUT }
15 [ [ WITH ] ( option [, ...] ) ]
16 where option can be one of:
18 FORMAT format_name
20 OIDS [ boolean ]
21 DELIMITER 'delimiter_character'
22 NULL 'null_string'
23 HEADER [ boolean ]
24 QUOTE 'quote_character'
25 ESCAPE 'escape_character'
26 FORCE_QUOTE { ( column_name [, ...] ) | * }
27 FORCE_NOT_NULL ( column_name [, ...] )
28 ENCODING 'encoding_name'
29
31 COPY moves data between PostgreSQL tables and standard file-system
32 files. COPY TO copies the contents of a table to a file, while COPY
33 FROM copies data from a file to a table (appending the data to whatever
34 is in the table already). COPY TO can also copy the results of a
35 SELECT query.
36 If a list of columns is specified, COPY will only copy the data in the
38 specified columns to or from the file. If there are any columns in the
39 table that are not in the column list, COPY FROM will insert the
40 default values for those columns.
41 COPY with a file name instructs the PostgreSQL server to directly read
43 from or write to a file. The file must be accessible to the server and
44 the name must be specified from the viewpoint of the server. When STDIN
45 or STDOUT is specified, data is transmitted via the connection between
46 the client and the server.
47
49 table_name
50 The name (optionally schema-qualified) of an existing table.
51 column_name
53 An optional list of columns to be copied. If no column list is
54 specified, all columns of the table will be copied.
55 query
57 A SELECT(7) or VALUES(7) command whose results are to be copied.
58 Note that parentheses are required around the query.
59 filename
61 The absolute path name of the input or output file. Windows users
62 might need to use an E'' string and double any backslashes used in
63 the path name.
64 STDIN
66 Specifies that input comes from the client application.
67 STDOUT
69 Specifies that output goes to the client application.
70 boolean
72 Specifies whether the selected option should be turned on or off.
73 You can write TRUE, ON, or 1 to enable the option, and FALSE, OFF,
74 or 0 to disable it. The boolean value can also be omitted, in which
75 case TRUE is assumed.
76 FORMAT
78 Selects the data format to be read or written: text, csv (Comma
79 Separated Values), or binary. The default is text.
80 OIDS
82 Specifies copying the OID for each row. (An error is raised if OIDS
83 is specified for a table that does not have OIDs, or in the case of
84 copying a query.)
85 DELIMITER
87 Specifies the character that separates columns within each row
88 (line) of the file. The default is a tab character in text format,
89 a comma in CSV format. This must be a single one-byte character.
90 This option is not allowed when using binary format.
91 NULL
93 Specifies the string that represents a null value. The default is
94 \N (backslash-N) in text format, and an unquoted empty string in
95 CSV format. You might prefer an empty string even in text format
96 for cases where you don't want to distinguish nulls from empty
97 strings. This option is not allowed when using binary format.
98 Note
100 When using COPY FROM, any data item that matches this string
101 will be stored as a null value, so you should make sure that
102 you use the same string as you used with COPY TO.
103 HEADER
105 Specifies that the file contains a header line with the names of
106 each column in the file. On output, the first line contains the
107 column names from the table, and on input, the first line is
108 ignored. This option is allowed only when using CSV format.
109 QUOTE
111 Specifies the quoting character to be used when a data value is
112 quoted. The default is double-quote. This must be a single one-byte
113 character. This option is allowed only when using CSV format.
114 ESCAPE
116 Specifies the character that should appear before a data character
117 that matches the QUOTE value. The default is the same as the QUOTE
118 value (so that the quoting character is doubled if it appears in
119 the data). This must be a single one-byte character. This option is
120 allowed only when using CSV format.
121 FORCE_QUOTE
123 Forces quoting to be used for all non-NULL values in each specified
124 column. NULL output is never quoted. If * is specified, non-NULL
125 values will be quoted in all columns. This option is allowed only
126 in COPY TO, and only when using CSV format.
127 FORCE_NOT_NULL
129 Do not match the specified columns' values against the null string.
130 In the default case where the null string is empty, this means that
131 empty values will be read as zero-length strings rather than nulls,
132 even when they are not quoted. This option is allowed only in COPY
133 FROM, and only when using CSV format.
134 ENCODING
136 Specifies that the file is encoded in the encoding_name. If this
137 option is omitted, the current client encoding is used. See the
138 Notes below for more details.
139
141 On successful completion, a COPY command returns a command tag of the
142 form
143 COPY count
145 The count is the number of rows copied.
147
149 COPY can only be used with plain tables, not with views. However, you
150 can write COPY (SELECT * FROM viewname) TO ....
151 COPY only deals with the specific table named; it does not copy data to
153 or from child tables. Thus for example COPY table TO shows the same
154 data as SELECT * FROM ONLY table. But COPY (SELECT * FROM table) TO ...
155 can be used to dump all of the data in an inheritance hierarchy.
156 You must have select privilege on the table whose values are read by
158 COPY TO, and insert privilege on the table into which values are
159 inserted by COPY FROM. It is sufficient to have column privileges on
160 the column(s) listed in the command.
161 Files named in a COPY command are read or written directly by the
163 server, not by the client application. Therefore, they must reside on
164 or be accessible to the database server machine, not the client. They
165 must be accessible to and readable or writable by the PostgreSQL user
166 (the user ID the server runs as), not the client. COPY naming a file
167 is only allowed to database superusers, since it allows reading or
168 writing any file that the server has privileges to access.
169 Do not confuse COPY with the psql instruction \copy invokes COPY FROM
171 STDIN or COPY TO STDOUT, and then fetches/stores the data in a file
172 accessible to the psql client. Thus, file accessibility and access
173 rights depend on the client rather than the server when \copy is used.
174 It is recommended that the file name used in COPY always be specified
176 as an absolute path. This is enforced by the server in the case of COPY
177 TO, but for COPY FROM you do have the option of reading from a file
178 specified by a relative path. The path will be interpreted relative to
179 the working directory of the server process (normally the cluster's
180 data directory), not the client's working directory.
181 COPY FROM will invoke any triggers and check constraints on the
183 destination table. However, it will not invoke rules.
184 COPY input and output is affected by DateStyle. To ensure portability
186 to other PostgreSQL installations that might use non-default DateStyle
187 settings, DateStyle should be set to ISO before using COPY TO. It is
188 also a good idea to avoid dumping data with IntervalStyle set to
189 sql_standard, because negative interval values might be misinterpreted
190 by a server that has a different setting for IntervalStyle.
191 Input data is interpreted according to ENCODING option or the current
193 client encoding, and output data is encoded in ENCODING or the current
194 client encoding, even if the data does not pass through the client but
195 is read from or written to a file directly by the server.
196 COPY stops operation at the first error. This should not lead to
198 problems in the event of a COPY TO, but the target table will already
199 have received earlier rows in a COPY FROM. These rows will not be
200 visible or accessible, but they still occupy disk space. This might
201 amount to a considerable amount of wasted disk space if the failure
202 happened well into a large copy operation. You might wish to invoke
203 VACUUM to recover the wasted space.
204
206 Text Format
207 When the text format is used, the data read or written is a text file
208 with one line per table row. Columns in a row are separated by the
209 delimiter character. The column values themselves are strings generated
210 by the output function, or acceptable to the input function, of each
211 attribute's data type. The specified null string is used in place of
212 columns that are null. COPY FROM will raise an error if any line of
213 the input file contains more or fewer columns than are expected. If
214 OIDS is specified, the OID is read or written as the first column,
215 preceding the user data columns.
216 End of data can be represented by a single line containing just
218 backslash-period (\.). An end-of-data marker is not necessary when
219 reading from a file, since the end of file serves perfectly well; it is
220 needed only when copying data to or from client applications using
221 pre-3.0 client protocol.
222 Backslash characters (\) can be used in the COPY data to quote data
224 characters that might otherwise be taken as row or column delimiters.
225 In particular, the following characters must be preceded by a backslash
226 if they appear as part of a column value: backslash itself, newline,
227 carriage return, and the current delimiter character.
228 The specified null string is sent by COPY TO without adding any
230 backslashes; conversely, COPY FROM matches the input against the null
231 string before removing backslashes. Therefore, a null string such as \N
232 cannot be confused with the actual data value \N (which would be
233 represented as \\N).
234 The following special backslash sequences are recognized by COPY FROM:
236 ┌─────────┬────────────────────────────┐
238 │Sequence │ Represents │
239 ├─────────┼────────────────────────────┤
240 │\b │ Backspace (ASCII 8) │
241 ├─────────┼────────────────────────────┤
242 │\f │ Form feed (ASCII 12) │
243 ├─────────┼────────────────────────────┤
244 │\n │ Newline (ASCII 10) │
245 ├─────────┼────────────────────────────┤
246 │\r │ Carriage return (ASCII 13) │
247 ├─────────┼────────────────────────────┤
248 │\t │ Tab (ASCII 9) │
249 ├─────────┼────────────────────────────┤
250 │\v │ Vertical tab (ASCII 11) │
251 ├─────────┼────────────────────────────┤
252 │\digits │ Backslash followed by one │
253 │ │ to three octal digits │
254 │ │ specifies │
255 │ │ the character with │
256 │ │ that numeric code │
257 ├─────────┼────────────────────────────┤
258 │\xdigits │ Backslash x followed by │
259 │ │ one or two hex digits │
260 │ │ specifies │
261 │ │ the character with │
262 │ │ that numeric code │
263 └─────────┴────────────────────────────┘
264 Presently, COPY TO will never emit an octal or hex-digits backslash
265 sequence, but it does use the other sequences listed above for those
266 control characters.
267 Any other backslashed character that is not mentioned in the above
269 table will be taken to represent itself. However, beware of adding
270 backslashes unnecessarily, since that might accidentally produce a
271 string matching the end-of-data marker (\.) or the null string (\N by
272 default). These strings will be recognized before any other backslash
273 processing is done.
274 It is strongly recommended that applications generating COPY data
276 convert data newlines and carriage returns to the \n and \r sequences
277 respectively. At present it is possible to represent a data carriage
278 return by a backslash and carriage return, and to represent a data
279 newline by a backslash and newline. However, these representations
280 might not be accepted in future releases. They are also highly
281 vulnerable to corruption if the COPY file is transferred across
282 different machines (for example, from Unix to Windows or vice versa).
283 COPY TO will terminate each row with a Unix-style newline (“\n”).
285 Servers running on Microsoft Windows instead output carriage
286 return/newline (“\r\n”), but only for COPY to a server file; for
287 consistency across platforms, COPY TO STDOUT always sends “\n”
288 regardless of server platform. COPY FROM can handle lines ending with
289 newlines, carriage returns, or carriage return/newlines. To reduce the
290 risk of error due to un-backslashed newlines or carriage returns that
291 were meant as data, COPY FROM will complain if the line endings in the
292 input are not all alike.
293 CSV Format
295 This format option is used for importing and exporting the Comma
296 Separated Value (CSV) file format used by many other programs, such as
297 spreadsheets. Instead of the escaping rules used by PostgreSQL's
298 standard text format, it produces and recognizes the common CSV
299 escaping mechanism.
300 The values in each record are separated by the DELIMITER character. If
302 the value contains the delimiter character, the QUOTE character, the
303 NULL string, a carriage return, or line feed character, then the whole
304 value is prefixed and suffixed by the QUOTE character, and any
305 occurrence within the value of a QUOTE character or the ESCAPE
306 character is preceded by the escape character. You can also use
307 FORCE_QUOTE to force quotes when outputting non-NULL values in specific
308 columns.
309 The CSV format has no standard way to distinguish a NULL value from an
311 empty string. PostgreSQL's COPY handles this by quoting. A NULL is
312 output as the NULL parameter string and is not quoted, while a non-NULL
313 value matching the NULL parameter string is quoted. For example, with
314 the default settings, a NULL is written as an unquoted empty string,
315 while an empty string data value is written with double quotes ("").
316 Reading values follows similar rules. You can use FORCE_NOT_NULL to
317 prevent NULL input comparisons for specific columns.
318 Because backslash is not a special character in the CSV format, \., the
320 end-of-data marker, could also appear as a data value. To avoid any
321 misinterpretation, a \. data value appearing as a lone entry on a line
322 is automatically quoted on output, and on input, if quoted, is not
323 interpreted as the end-of-data marker. If you are loading a file
324 created by another application that has a single unquoted column and
325 might have a value of \., you might need to quote that value in the
326 input file.
327 Note
329 In CSV format, all characters are significant. A quoted value
330 surrounded by white space, or any characters other than DELIMITER,
331 will include those characters. This can cause errors if you import
332 data from a system that pads CSV lines with white space out to some
333 fixed width. If such a situation arises you might need to
334 preprocess the CSV file to remove the trailing white space, before
335 importing the data into PostgreSQL.
336 Note
338 CSV format will both recognize and produce CSV files with quoted
339 values containing embedded carriage returns and line feeds. Thus
340 the files are not strictly one line per table row like text-format
341 files.
342 Note
344 Many programs produce strange and occasionally perverse CSV files,
345 so the file format is more a convention than a standard. Thus you
346 might encounter some files that cannot be imported using this
347 mechanism, and COPY might produce files that other programs cannot
348 process.
349 Binary Format
351 The binary format option causes all data to be stored/read as binary
352 format rather than as text. It is somewhat faster than the text and CSV
353 formats, but a binary-format file is less portable across machine
354 architectures and PostgreSQL versions. Also, the binary format is very
355 data type specific; for example it will not work to output binary data
356 from a smallint column and read it into an integer column, even though
357 that would work fine in text format.
358 The binary file format consists of a file header, zero or more tuples
360 containing the row data, and a file trailer. Headers and data are in
361 network byte order.
362 Note
364 PostgreSQL releases before 7.4 used a different binary file format.
365 File Header
367 The file header consists of 15 bytes of fixed fields, followed by a
368 variable-length header extension area. The fixed fields are:
369 Signature
371 11-byte sequence PGCOPY\n\377\r\n\0 — note that the zero byte
372 is a required part of the signature. (The signature is designed
373 to allow easy identification of files that have been munged by
374 a non-8-bit-clean transfer. This signature will be changed by
375 end-of-line-translation filters, dropped zero bytes, dropped
376 high bits, or parity changes.)
377 Flags field
379 32-bit integer bit mask to denote important aspects of the file
380 format. Bits are numbered from 0 (LSB) to 31 (MSB). Note that
381 this field is stored in network byte order (most significant
382 byte first), as are all the integer fields used in the file
383 format. Bits 16-31 are reserved to denote critical file format
384 issues; a reader should abort if it finds an unexpected bit set
385 in this range. Bits 0-15 are reserved to signal
386 backwards-compatible format issues; a reader should simply
387 ignore any unexpected bits set in this range. Currently only
388 one flag bit is defined, and the rest must be zero:
389 Bit 16
391 if 1, OIDs are included in the data; if 0, not
392 Header extension area length
394 32-bit integer, length in bytes of remainder of header, not
395 including self. Currently, this is zero, and the first tuple
396 follows immediately. Future changes to the format might allow
397 additional data to be present in the header. A reader should
398 silently skip over any header extension data it does not know
399 what to do with.
400 The header extension area is envisioned to contain a sequence of
402 self-identifying chunks. The flags field is not intended to tell
403 readers what is in the extension area. Specific design of header
404 extension contents is left for a later release.
405 This design allows for both backwards-compatible header additions
407 (add header extension chunks, or set low-order flag bits) and
408 non-backwards-compatible changes (set high-order flag bits to
409 signal such changes, and add supporting data to the extension area
410 if needed).
411 Tuples
413 Each tuple begins with a 16-bit integer count of the number of
414 fields in the tuple. (Presently, all tuples in a table will have
415 the same count, but that might not always be true.) Then, repeated
416 for each field in the tuple, there is a 32-bit length word followed
417 by that many bytes of field data. (The length word does not include
418 itself, and can be zero.) As a special case, -1 indicates a NULL
419 field value. No value bytes follow in the NULL case.
420 There is no alignment padding or any other extra data between
422 fields.
423 Presently, all data values in a binary-format file are assumed to
425 be in binary format (format code one). It is anticipated that a
426 future extension might add a header field that allows per-column
427 format codes to be specified.
428 To determine the appropriate binary format for the actual tuple
430 data you should consult the PostgreSQL source, in particular the
431 *send and *recv functions for each column's data type (typically
432 these functions are found in the src/backend/utils/adt/ directory
433 of the source distribution).
434 If OIDs are included in the file, the OID field immediately follows
436 the field-count word. It is a normal field except that it's not
437 included in the field-count. In particular it has a length word —
438 this will allow handling of 4-byte vs. 8-byte OIDs without too much
439 pain, and will allow OIDs to be shown as null if that ever proves
440 desirable.
441 File Trailer
443 The file trailer consists of a 16-bit integer word containing -1.
444 This is easily distinguished from a tuple's field-count word.
445 A reader should report an error if a field-count word is neither -1
447 nor the expected number of columns. This provides an extra check
448 against somehow getting out of sync with the data.
449
451 The following example copies a table to the client using the vertical
452 bar (|) as the field delimiter:
453 COPY country TO STDOUT (DELIMITER '|');
455 To copy data from a file into the country table:
457 COPY country FROM '/usr1/proj/bray/sql/country_data';
459 To copy into a file just the countries whose names start with 'A':
461 COPY (SELECT * FROM country WHERE country_name LIKE 'A%') TO '/usr1/proj/bray/sql/a_list_countries.copy';
463 Here is a sample of data suitable for copying into a table from STDIN:
465 AF AFGHANISTAN
467 AL ALBANIA
468 DZ ALGERIA
469 ZM ZAMBIA
470 ZW ZIMBABWE
471 Note that the white space on each line is actually a tab character.
473 The following is the same data, output in binary format. The data is
475 shown after filtering through the Unix utility od -c. The table has
476 three columns; the first has type char(2), the second has type text,
477 and the third has type integer. All the rows have a null value in the
478 third column.
479 0000000 P G C O P Y \n 377 \r \n \0 \0 \0 \0 \0 \0
481 0000020 \0 \0 \0 \0 003 \0 \0 \0 002 A F \0 \0 \0 013 A
482 0000040 F G H A N I S T A N 377 377 377 377 \0 003
483 0000060 \0 \0 \0 002 A L \0 \0 \0 007 A L B A N I
484 0000100 A 377 377 377 377 \0 003 \0 \0 \0 002 D Z \0 \0 \0
485 0000120 007 A L G E R I A 377 377 377 377 \0 003 \0 \0
486 0000140 \0 002 Z M \0 \0 \0 006 Z A M B I A 377 377
487 0000160 377 377 \0 003 \0 \0 \0 002 Z W \0 \0 \0 \b Z I
488 0000200 M B A B W E 377 377 377 377 377 377
489
491 There is no COPY statement in the SQL standard.
492 The following syntax was used before PostgreSQL version 9.0 and is
494 still supported:
495 COPY table_name [ ( column_name [, ...] ) ]
497 FROM { 'filename' | STDIN }
498 [ [ WITH ]
499 [ BINARY ]
500 [ OIDS ]
501 [ DELIMITER [ AS ] 'delimiter' ]
502 [ NULL [ AS ] 'null string' ]
503 [ CSV [ HEADER ]
504 [ QUOTE [ AS ] 'quote' ]
505 [ ESCAPE [ AS ] 'escape' ]
506 [ FORCE NOT NULL column_name [, ...] ] ] ]
507 COPY { table_name [ ( column_name [, ...] ) ] | ( query ) }
509 TO { 'filename' | STDOUT }
510 [ [ WITH ]
511 [ BINARY ]
512 [ OIDS ]
513 [ DELIMITER [ AS ] 'delimiter' ]
514 [ NULL [ AS ] 'null string' ]
515 [ CSV [ HEADER ]
516 [ QUOTE [ AS ] 'quote' ]
517 [ ESCAPE [ AS ] 'escape' ]
518 [ FORCE QUOTE { column_name [, ...] | * } ] ] ]
519 Note that in this syntax, BINARY and CSV are treated as independent
521 keywords, not as arguments of a FORMAT option.
522 The following syntax was used before PostgreSQL version 7.3 and is
524 still supported:
525 COPY [ BINARY ] table_name [ WITH OIDS ]
527 FROM { 'filename' | STDIN }
528 [ [USING] DELIMITERS 'delimiter' ]
529 [ WITH NULL AS 'null string' ]
530 COPY [ BINARY ] table_name [ WITH OIDS ]
532 TO { 'filename' | STDOUT }
533 [ [USING] DELIMITERS 'delimiter' ]
534 [ WITH NULL AS 'null string' ]
535PostgreSQL 9.2.24 2017-11-06 COPY(7)