Skip to content

Commit 49b27ab

Browse files
ItGackyItGacky
committed
Add string functions: concat(), concat_ws(), left(), right(), and reverse().
Pavel Stehule, reviewed by me.
1 parent b9defe0 commit 49b27ab

File tree

7 files changed

+331
-6
lines changed

7 files changed

+331
-6
lines changed

‎doc/src/sgml/func.sgml

Lines changed: 84 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -1,4 +1,4 @@
1-
<!-- $PostgreSQL: pgsql/doc/src/sgml/func.sgml,v 1.529 2010/08/17 04:37:20 petere Exp $ -->
1+
<!-- $PostgreSQL: pgsql/doc/src/sgml/func.sgml,v 1.530 2010/08/24 06:30:43 itagaki Exp $ -->
22

33
<chapter id="functions">
44
<title>Functions and Operators</title>
@@ -1250,6 +1250,12 @@
12501250
<indexterm>
12511251
<primary>chr</primary>
12521252
</indexterm>
1253+
<indexterm>
1254+
<primary>concat</primary>
1255+
</indexterm>
1256+
<indexterm>
1257+
<primary>concat_ws</primary>
1258+
</indexterm>
12531259
<indexterm>
12541260
<primary>convert</primary>
12551261
</indexterm>
@@ -1268,6 +1274,9 @@
12681274
<indexterm>
12691275
<primary>initcap</primary>
12701276
</indexterm>
1277+
<indexterm>
1278+
<primary>left</primary>
1279+
</indexterm>
12711280
<indexterm>
12721281
<primary>lpad</primary>
12731282
</indexterm>
@@ -1295,6 +1304,12 @@
12951304
<indexterm>
12961305
<primary>replace</primary>
12971306
</indexterm>
1307+
<indexterm>
1308+
<primary>reverse</primary>
1309+
</indexterm>
1310+
<indexterm>
1311+
<primary>right</primary>
1312+
</indexterm>
12981313
<indexterm>
12991314
<primary>rpad</primary>
13001315
</indexterm>
@@ -1374,6 +1389,34 @@
13741389
<entry><literal>A</literal></entry>
13751390
</row>
13761391

1392+
<row>
1393+
<entry>
1394+
<literal><function>concat</function>(<parameter>str</parameter> <type>"any"</type>
1395+
[, <parameter>str</parameter> <type>"any"</type> [, ...] ])</literal>
1396+
</entry>
1397+
<entry><type>text</type></entry>
1398+
<entry>
1399+
Concatenate all arguments. NULL arguments are ignored.
1400+
</entry>
1401+
<entry><literal>concat('abcde', 2, NULL, 22)</literal></entry>
1402+
<entry><literal>abcde222</literal></entry>
1403+
</row>
1404+
1405+
<row>
1406+
<entry>
1407+
<literal><function>concat_ws</function>(<parameter>sep</parameter> <type>text</type>,
1408+
<parameter>str</parameter> <type>"any"</type>
1409+
[, <parameter>str</parameter> <type>"any"</type> [, ...] ])</literal>
1410+
</entry>
1411+
<entry><type>text</type></entry>
1412+
<entry>
1413+
Concatenate all but first arguments with separators. The first
1414+
parameter is used as a separator. NULL arguments are ignored.
1415+
</entry>
1416+
<entry><literal>concat_ws(',', 'abcde', 2, NULL, 22)</literal></entry>
1417+
<entry><literal>abcde,2,22</literal></entry>
1418+
</row>
1419+
13771420
<row>
13781421
<entry>
13791422
<literal><function>convert</function>(<parameter>string</parameter> <type>bytea</type>,
@@ -1465,6 +1508,20 @@
14651508
<entry><literal>Hi Thomas</literal></entry>
14661509
</row>
14671510

1511+
<row>
1512+
<entry>
1513+
<literal><function>left</function>(<parameter>str</parameter> <type>text</type>,
1514+
<parameter>n</parameter> <type>int</type>)</literal>
1515+
</entry>
1516+
<entry><type>text</type></entry>
1517+
<entry>
1518+
Return first <replaceable>n</> characters in the string. When <replaceable>n</>
1519+
is negative, return all but last |<replaceable>n</>| characters.
1520+
</entry>
1521+
<entry><literal>left('abcde', 2)</literal></entry>
1522+
<entry><literal>ab</literal></entry>
1523+
</row>
1524+
14681525
<row>
14691526
<entry><literal><function>length</function>(<parameter>string</parameter>)</literal></entry>
14701527
<entry><type>int</type></entry>
@@ -1678,6 +1735,32 @@
16781735
<entry><literal>abXXefabXXef</literal></entry>
16791736
</row>
16801737

1738+
<row>
1739+
<entry>
1740+
<literal><function>reverse</function>(<parameter>str</parameter>)</literal>
1741+
</entry>
1742+
<entry><type>text</type></entry>
1743+
<entry>
1744+
Return reversed string.
1745+
</entry>
1746+
<entry><literal>reverse('abcde')</literal></entry>
1747+
<entry><literal>edcba</literal></entry>
1748+
</row>
1749+
1750+
<row>
1751+
<entry>
1752+
<literal><function>right</function>(<parameter>str</parameter> <type>text</type>,
1753+
<parameter>n</parameter> <type>int</type>)</literal>
1754+
</entry>
1755+
<entry><type>text</type></entry>
1756+
<entry>
1757+
Return last <replaceable>n</> characters in the string. When <replaceable>n</>
1758+
is negative, return all but first |<replaceable>n</>| characters.
1759+
</entry>
1760+
<entry><literal>right('abcde', 2)</literal></entry>
1761+
<entry><literal>de</literal></entry>
1762+
</row>
1763+
16811764
<row>
16821765
<entry>
16831766
<literal><function>rpad</function>(<parameter>string</parameter> <type>text</type>,

‎src/backend/utils/adt/varlena.c

Lines changed: 147 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -8,7 +8,7 @@
88
*
99
*
1010
* IDENTIFICATION
11-
* $PostgreSQL: pgsql/src/backend/utils/adt/varlena.c,v 1.179 2010/08/10 21:51:00 tgl Exp $
11+
* $PostgreSQL: pgsql/src/backend/utils/adt/varlena.c,v 1.180 2010/08/24 06:30:43 itagaki Exp $
1212
*
1313
*-------------------------------------------------------------------------
1414
*/
@@ -3556,3 +3556,149 @@ string_agg_finalfn(PG_FUNCTION_ARGS)
35563556
else
35573557
PG_RETURN_NULL();
35583558
}
3559+
3560+
static text *
3561+
concat_internal(const char *sepstr, int seplen, int argidx, FunctionCallInfo fcinfo)
3562+
{
3563+
StringInfoData str;
3564+
text *result;
3565+
int i;
3566+
3567+
initStringInfo(&str);
3568+
3569+
for (i = argidx; i < PG_NARGS(); i++)
3570+
{
3571+
if (!PG_ARGISNULL(i))
3572+
{
3573+
Oid valtype;
3574+
Datum value;
3575+
Oid typOutput;
3576+
bool typIsVarlena;
3577+
3578+
if (i > argidx)
3579+
appendBinaryStringInfo(&str, sepstr, seplen);
3580+
3581+
/* append n-th value */
3582+
value = PG_GETARG_DATUM(i);
3583+
valtype = get_fn_expr_argtype(fcinfo->flinfo, i);
3584+
getTypeOutputInfo(valtype, &typOutput, &typIsVarlena);
3585+
appendStringInfoString(&str,
3586+
OidOutputFunctionCall(typOutput, value));
3587+
}
3588+
}
3589+
3590+
result = cstring_to_text_with_len(str.data, str.len);
3591+
pfree(str.data);
3592+
3593+
return result;
3594+
}
3595+
3596+
/*
3597+
* Concatenate all arguments. NULL arguments are ignored.
3598+
*/
3599+
Datum
3600+
text_concat(PG_FUNCTION_ARGS)
3601+
{
3602+
PG_RETURN_TEXT_P(concat_internal(NULL, 0, 0, fcinfo));
3603+
}
3604+
3605+
/*
3606+
* Concatenate all but first argument values with separators. The first
3607+
* parameter is used as a separator. NULL arguments are ignored.
3608+
*/
3609+
Datum
3610+
text_concat_ws(PG_FUNCTION_ARGS)
3611+
{
3612+
text *sep;
3613+
3614+
/* return NULL when separator is NULL */
3615+
if (PG_ARGISNULL(0))
3616+
PG_RETURN_NULL();
3617+
3618+
sep = PG_GETARG_TEXT_PP(0);
3619+
3620+
PG_RETURN_TEXT_P(concat_internal(
3621+
VARDATA_ANY(sep), VARSIZE_ANY_EXHDR(sep), 1, fcinfo));
3622+
}
3623+
3624+
/*
3625+
* Return first n characters in the string. When n is negative,
3626+
* return all but last |n| characters.
3627+
*/
3628+
Datum
3629+
text_left(PG_FUNCTION_ARGS)
3630+
{
3631+
text *str = PG_GETARG_TEXT_PP(0);
3632+
const char *p = VARDATA_ANY(str);
3633+
int len = VARSIZE_ANY_EXHDR(str);
3634+
int n = PG_GETARG_INT32(1);
3635+
int rlen;
3636+
3637+
if (n < 0)
3638+
n = pg_mbstrlen_with_len(p, len) + n;
3639+
rlen = pg_mbcharcliplen(p, len, n);
3640+
3641+
PG_RETURN_TEXT_P(cstring_to_text_with_len(p, rlen));
3642+
}
3643+
3644+
/*
3645+
* Return last n characters in the string. When n is negative,
3646+
* return all but first |n| characters.
3647+
*/
3648+
Datum
3649+
text_right(PG_FUNCTION_ARGS)
3650+
{
3651+
text *str = PG_GETARG_TEXT_PP(0);
3652+
const char *p = VARDATA_ANY(str);
3653+
int len = VARSIZE_ANY_EXHDR(str);
3654+
int n = PG_GETARG_INT32(1);
3655+
int off;
3656+
3657+
if (n < 0)
3658+
n = -n;
3659+
else
3660+
n = pg_mbstrlen_with_len(p, len) - n;
3661+
off = pg_mbcharcliplen(p, len, n);
3662+
3663+
PG_RETURN_TEXT_P(cstring_to_text_with_len(p + off, len - off));
3664+
}
3665+
3666+
/*
3667+
* Return reversed string
3668+
*/
3669+
Datum
3670+
text_reverse(PG_FUNCTION_ARGS)
3671+
{
3672+
text *str = PG_GETARG_TEXT_PP(0);
3673+
const char *p = VARDATA_ANY(str);
3674+
int len = VARSIZE_ANY_EXHDR(str);
3675+
const char *endp = p + len;
3676+
text *result;
3677+
char *dst;
3678+
3679+
result = palloc(len + VARHDRSZ);
3680+
dst = (char*) VARDATA(result) + len;
3681+
SET_VARSIZE(result, len + VARHDRSZ);
3682+
3683+
if (pg_database_encoding_max_length() > 1)
3684+
{
3685+
/* multibyte version */
3686+
while (p < endp)
3687+
{
3688+
int sz;
3689+
3690+
sz = pg_mblen(p);
3691+
dst -= sz;
3692+
memcpy(dst, p, sz);
3693+
p += sz;
3694+
}
3695+
}
3696+
else
3697+
{
3698+
/* single byte version */
3699+
while (p < endp)
3700+
*(--dst) = *p++;
3701+
}
3702+
3703+
PG_RETURN_TEXT_P(result);
3704+
}

‎src/include/catalog/catversion.h

Lines changed: 2 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -37,7 +37,7 @@
3737
* Portions Copyright (c) 1996-2010, PostgreSQL Global Development Group
3838
* Portions Copyright (c) 1994, Regents of the University of California
3939
*
40-
* $PostgreSQL: pgsql/src/include/catalog/catversion.h,v 1.596 2010/08/21 10:59:17 mha Exp $
40+
* $PostgreSQL: pgsql/src/include/catalog/catversion.h,v 1.597 2010/08/24 06:30:43 itagaki Exp $
4141
*
4242
*-------------------------------------------------------------------------
4343
*/
@@ -53,6 +53,6 @@
5353
*/
5454

5555
/* yyyymmddN */
56-
#define CATALOG_VERSION_NO 201008211
56+
#define CATALOG_VERSION_NO 201008241
5757

5858
#endif

‎src/include/catalog/pg_proc.h

Lines changed: 11 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -7,7 +7,7 @@
77
* Portions Copyright (c) 1996-2010, PostgreSQL Global Development Group
88
* Portions Copyright (c) 1994, Regents of the University of California
99
*
10-
* $PostgreSQL: pgsql/src/include/catalog/pg_proc.h,v 1.580 2010/08/21 10:59:17 mha Exp $
10+
* $PostgreSQL: pgsql/src/include/catalog/pg_proc.h,v 1.581 2010/08/24 06:30:43 itagaki Exp $
1111
*
1212
* NOTES
1313
* The script catalog/genbki.pl reads this file and generates .bki
@@ -2722,6 +2722,16 @@ DESCR("I/O");
27222722
DATA(insert OID = 1799 ( oidout PGNSP PGUID 12 1 0 0 f f f t f i 1 0 2275 "26" _null_ _null_ _null_ _null_ oidout _null_ _null_ _null_ ));
27232723
DESCR("I/O");
27242724

2725+
DATA(insert OID = 3058 ( concat PGNSP PGUID 12 1 0 2276 f f f f f s 1 0 25 "2276" "{2276}" "{v}" _null_ _null_ text_concat _null_ _null_ _null_ ));
2726+
DESCR("concatenate values");
2727+
DATA(insert OID = 3059 ( concat_ws PGNSP PGUID 12 1 0 2276 f f f f f s 2 0 25 "25 2276" "{25,2276}" "{i,v}" _null_ _null_ text_concat_ws _null_ _null_ _null_ ));
2728+
DESCR("concatenate values with separators");
2729+
DATA(insert OID = 3060 ( left PGNSP PGUID 12 1 0 0 f f f t f i 2 0 25 "25 23" _null_ _null_ _null_ _null_ text_left _null_ _null_ _null_ ));
2730+
DESCR("return the first n characters");
2731+
DATA(insert OID = 3061 ( right PGNSP PGUID 12 1 0 0 f f f t f i 2 0 25 "25 23" _null_ _null_ _null_ _null_ text_right _null_ _null_ _null_ ));
2732+
DESCR("return the last n characters");
2733+
DATA(insert OID = 3062 ( reverse PGNSP PGUID 12 1 0 0 f f f t f i 1 0 25 "25" _null_ _null_ _null_ _null_ text_reverse _null_ _null_ _null_ ));
2734+
DESCR("reverse text");
27252735

27262736
DATA(insert OID = 1810 ( bit_length PGNSP PGUID 14 1 0 0 f f f t f i 1 0 23 "17" _null_ _null_ _null_ _null_ "select pg_catalog.octet_length($1) * 8" _null_ _null_ _null_ ));
27272737
DESCR("length in bits");

‎src/include/utils/builtins.h

Lines changed: 7 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -7,7 +7,7 @@
77
* Portions Copyright (c) 1996-2010, PostgreSQL Global Development Group
88
* Portions Copyright (c) 1994, Regents of the University of California
99
*
10-
* $PostgreSQL: pgsql/src/include/utils/builtins.h,v 1.354 2010/08/10 21:51:00 tgl Exp $
10+
* $PostgreSQL: pgsql/src/include/utils/builtins.h,v 1.355 2010/08/24 06:30:44 itagaki Exp $
1111
*
1212
*-------------------------------------------------------------------------
1313
*/
@@ -733,6 +733,12 @@ extern Datum pg_column_size(PG_FUNCTION_ARGS);
733733
extern Datum string_agg_transfn(PG_FUNCTION_ARGS);
734734
extern Datum string_agg_finalfn(PG_FUNCTION_ARGS);
735735

736+
extern Datum text_concat(PG_FUNCTION_ARGS);
737+
extern Datum text_concat_ws(PG_FUNCTION_ARGS);
738+
extern Datum text_left(PG_FUNCTION_ARGS);
739+
extern Datum text_right(PG_FUNCTION_ARGS);
740+
extern Datum text_reverse(PG_FUNCTION_ARGS);
741+
736742
/* version.c */
737743
extern Datum pgsql_version(PG_FUNCTION_ARGS);
738744

0 commit comments

Comments
 (0)
pFad - Phonifier reborn

Pfad - The Proxy pFad of © 2024 Garber Painting. All rights reserved.

Note: This service is not intended for secure transactions such as banking, social media, email, or purchasing. Use at your own risk. We assume no liability whatsoever for broken pages.


Alternative Proxies:

Alternative Proxy

pFad Proxy

pFad v3 Proxy

pFad v4 Proxy