diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index 8f6e2d04bd..5c1cff3618 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -13698,6 +13698,10 @@ SELECT pg_type_is_visible('myschema.widget'::regtype); pg_typeof + + collation for + + lists functions that extract information from the system catalogs. @@ -13859,6 +13863,11 @@ SELECT pg_type_is_visible('myschema.widget'::regtype); regtype get the data type of any value + + collation for (any) + text + get the collation of the argument + @@ -13983,6 +13992,27 @@ SELECT typlen FROM pg_type WHERE oid = pg_typeof(33); 4 (1 row) + + + + The expression collation for returns the collation of the + value that is passed to it. Example: + +SELECT collation for (description) FROM pg_description LIMIT 1; + pg_collation_for +------------------ + "default" +(1 row) + +SELECT collation for ('foo' COLLATE "de_DE"); + pg_collation_for +------------------ + "de_DE" +(1 row) + + The value might be quoted and schema-qualified. If no collation is derived + for the argument expression, then a null value is returned. If the argument + is not of a collatable data type, then an error is raised. diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y index d1ce2ab042..9aea2cd80b 100644 --- a/src/backend/parser/gram.y +++ b/src/backend/parser/gram.y @@ -10701,6 +10701,19 @@ func_expr: func_name '(' ')' over_clause n->location = @1; $$ = (Node *)n; } + | COLLATION FOR '(' a_expr ')' + { + FuncCall *n = makeNode(FuncCall); + n->funcname = SystemFuncName("pg_collation_for"); + n->args = list_make1($4); + n->agg_order = NIL; + n->agg_star = FALSE; + n->agg_distinct = FALSE; + n->func_variadic = FALSE; + n->over = NULL; + n->location = @1; + $$ = (Node *)n; + } | CURRENT_DATE { /* @@ -12152,7 +12165,6 @@ unreserved_keyword: | CLASS | CLOSE | CLUSTER - | COLLATION | COMMENT | COMMENTS | COMMIT @@ -12491,6 +12503,7 @@ reserved_keyword: | CAST | CHECK | COLLATE + | COLLATION | COLUMN | CONSTRAINT | CREATE diff --git a/src/backend/utils/adt/misc.c b/src/backend/utils/adt/misc.c index 3de6a5c992..6a1b477147 100644 --- a/src/backend/utils/adt/misc.c +++ b/src/backend/utils/adt/misc.c @@ -32,6 +32,7 @@ #include "storage/pmsignal.h" #include "storage/proc.h" #include "storage/procarray.h" +#include "utils/lsyscache.h" #include "tcop/tcopprot.h" #include "utils/builtins.h" #include "utils/timestamp.h" @@ -492,3 +493,29 @@ pg_typeof(PG_FUNCTION_ARGS) { PG_RETURN_OID(get_fn_expr_argtype(fcinfo->flinfo, 0)); } + + +/* + * Implementation of the COLLATE FOR expression; returns the collation + * of the argument. + */ +Datum +pg_collation_for(PG_FUNCTION_ARGS) +{ + Oid typeid; + Oid collid; + + typeid = get_fn_expr_argtype(fcinfo->flinfo, 0); + if (!typeid) + PG_RETURN_NULL(); + if (!type_is_collatable(typeid) && typeid != UNKNOWNOID) + ereport(ERROR, + (errcode(ERRCODE_DATATYPE_MISMATCH), + errmsg("collations are not supported by type %s", + format_type_be(typeid)))); + + collid = PG_GET_COLLATION(); + if (!collid) + PG_RETURN_NULL(); + PG_RETURN_TEXT_P(cstring_to_text(generate_collation_name(collid))); +} diff --git a/src/include/catalog/catversion.h b/src/include/catalog/catversion.h index e5fbbfc8fd..0335347155 100644 --- a/src/include/catalog/catversion.h +++ b/src/include/catalog/catversion.h @@ -53,6 +53,6 @@ */ /* yyyymmddN */ -#define CATALOG_VERSION_NO 201203011 +#define CATALOG_VERSION_NO 201203021 #endif diff --git a/src/include/catalog/pg_proc.h b/src/include/catalog/pg_proc.h index 8700d0d958..b476d47579 100644 --- a/src/include/catalog/pg_proc.h +++ b/src/include/catalog/pg_proc.h @@ -1953,6 +1953,8 @@ DESCR("convert generic options array to name/value table"); DATA(insert OID = 1619 ( pg_typeof PGNSP PGUID 12 1 0 0 0 f f f f f f s 1 0 2206 "2276" _null_ _null_ _null_ _null_ pg_typeof _null_ _null_ _null_ )); DESCR("type of the argument"); +DATA(insert OID = 3162 ( pg_collation_for PGNSP PGUID 12 1 0 0 0 f f f f f f s 1 0 25 "2276" _null_ _null_ _null_ _null_ pg_collation_for _null_ _null_ _null_ )); +DESCR("collation of the argument; implementation of the COLLATION FOR expression"); /* Deferrable unique constraint trigger */ DATA(insert OID = 1250 ( unique_key_recheck PGNSP PGUID 12 1 0 0 0 f f f f t f v 0 0 2279 "" _null_ _null_ _null_ _null_ unique_key_recheck _null_ _null_ _null_ )); diff --git a/src/include/parser/kwlist.h b/src/include/parser/kwlist.h index bf71ee5414..9f6f6d354f 100644 --- a/src/include/parser/kwlist.h +++ b/src/include/parser/kwlist.h @@ -79,7 +79,7 @@ PG_KEYWORD("close", CLOSE, UNRESERVED_KEYWORD) PG_KEYWORD("cluster", CLUSTER, UNRESERVED_KEYWORD) PG_KEYWORD("coalesce", COALESCE, COL_NAME_KEYWORD) PG_KEYWORD("collate", COLLATE, RESERVED_KEYWORD) -PG_KEYWORD("collation", COLLATION, UNRESERVED_KEYWORD) +PG_KEYWORD("collation", COLLATION, RESERVED_KEYWORD) PG_KEYWORD("column", COLUMN, RESERVED_KEYWORD) PG_KEYWORD("comment", COMMENT, UNRESERVED_KEYWORD) PG_KEYWORD("comments", COMMENTS, UNRESERVED_KEYWORD) diff --git a/src/include/utils/builtins.h b/src/include/utils/builtins.h index fe253bcc7c..9fda7ad28e 100644 --- a/src/include/utils/builtins.h +++ b/src/include/utils/builtins.h @@ -480,6 +480,7 @@ extern Datum pg_rotate_logfile(PG_FUNCTION_ARGS); extern Datum pg_sleep(PG_FUNCTION_ARGS); extern Datum pg_get_keywords(PG_FUNCTION_ARGS); extern Datum pg_typeof(PG_FUNCTION_ARGS); +extern Datum pg_collation_for(PG_FUNCTION_ARGS); /* oid.c */ extern Datum oidin(PG_FUNCTION_ARGS); diff --git a/src/test/regress/expected/collate.out b/src/test/regress/expected/collate.out index a15e6911b0..81ac6de7b3 100644 --- a/src/test/regress/expected/collate.out +++ b/src/test/regress/expected/collate.out @@ -577,6 +577,26 @@ RESET enable_nestloop; -- 9.1 bug with useless COLLATE in an expression subject to length coercion CREATE TEMP TABLE vctable (f1 varchar(25)); INSERT INTO vctable VALUES ('foo' COLLATE "C"); +SELECT collation for ('foo'); -- unknown type - null + pg_collation_for +------------------ + +(1 row) + +SELECT collation for ('foo'::text); + pg_collation_for +------------------ + "default" +(1 row) + +SELECT collation for ((SELECT a FROM collate_test1 LIMIT 1)); -- non-collatable type - error +ERROR: collations are not supported by type integer +SELECT collation for ((SELECT b FROM collate_test1 LIMIT 1)); + pg_collation_for +------------------ + "C" +(1 row) + -- -- Clean up. Many of these table names will be re-used if the user is -- trying to run any platform-specific collation tests later, so we diff --git a/src/test/regress/sql/collate.sql b/src/test/regress/sql/collate.sql index f72f3edb9d..3c960e7ed9 100644 --- a/src/test/regress/sql/collate.sql +++ b/src/test/regress/sql/collate.sql @@ -219,6 +219,13 @@ RESET enable_nestloop; CREATE TEMP TABLE vctable (f1 varchar(25)); INSERT INTO vctable VALUES ('foo' COLLATE "C"); + +SELECT collation for ('foo'); -- unknown type - null +SELECT collation for ('foo'::text); +SELECT collation for ((SELECT a FROM collate_test1 LIMIT 1)); -- non-collatable type - error +SELECT collation for ((SELECT b FROM collate_test1 LIMIT 1)); + + -- -- Clean up. Many of these table names will be re-used if the user is -- trying to run any platform-specific collation tests later, so we