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jgemignani pushed a commit to branch PG14
in repository https://gitbox.apache.org/repos/asf/age.git
The following commit(s) were added to refs/heads/PG14 by this push:
new 7fbee760 Add graph_exists function (#1958) (#1967)
7fbee760 is described below
commit 7fbee76085c1585507327854b40725aad4df66e3
Author: Rafsun Masud <[email protected]>
AuthorDate: Tue Jul 9 11:22:39 2024 -0700
Add graph_exists function (#1958) (#1967)
This function returns if a graph exists.
---
age--1.5.0--y.y.y.sql | 4 +++
regress/expected/catalog.out | 64 +++++++++++++++++++++++++++++++++++
regress/sql/catalog.sql | 29 ++++++++++++++--
sql/age_agtype.sql | 4 +++
src/backend/commands/graph_commands.c | 29 +++++++++++++++-
5 files changed, 127 insertions(+), 3 deletions(-)
diff --git a/age--1.5.0--y.y.y.sql b/age--1.5.0--y.y.y.sql
index ef5bf0a6..1620dfb4 100644
--- a/age--1.5.0--y.y.y.sql
+++ b/age--1.5.0--y.y.y.sql
@@ -125,3 +125,7 @@ CREATE FUNCTION ag_catalog.age_graph_stats(agtype)
PARALLEL SAFE
AS 'MODULE_PATHNAME';
+CREATE FUNCTION ag_catalog.graph_exists(graph_name name)
+ RETURNS agtype
+ LANGUAGE c
+ AS 'MODULE_PATHNAME', 'age_graph_exists';
diff --git a/regress/expected/catalog.out b/regress/expected/catalog.out
index bc7b9434..d06a0ce6 100644
--- a/regress/expected/catalog.out
+++ b/regress/expected/catalog.out
@@ -393,6 +393,70 @@ SELECT create_vlabel(NULL, NULL);
ERROR: graph name must not be NULL
SELECT create_elabel(NULL, NULL);
ERROR: graph name must not be NULL
+-- age_graph_exists()
+CREATE FUNCTION raise_notice(graph_name TEXT)
+RETURNS void AS $$
+DECLARE
+ res BOOLEAN;
+BEGIN
+ -- this tests whether graph_exists works with IF-ELSE.
+ SELECT graph_exists('graph1') INTO res;
+ IF res THEN
+ RAISE NOTICE 'graph exists';
+ ELSE
+ RAISE NOTICE 'graph does not exist';
+ END IF;
+END $$ LANGUAGE plpgsql;
+SELECT graph_exists('graph1');
+ graph_exists
+--------------
+ false
+(1 row)
+
+SELECT create_graph('graph1');
+NOTICE: graph "graph1" has been created
+ create_graph
+--------------
+
+(1 row)
+
+SELECT graph_exists('graph1');
+ graph_exists
+--------------
+ true
+(1 row)
+
+SELECT raise_notice('graph1');
+NOTICE: graph exists
+ raise_notice
+--------------
+
+(1 row)
+
+SELECT drop_graph('graph1', true);
+NOTICE: drop cascades to 2 other objects
+DETAIL: drop cascades to table graph1._ag_label_vertex
+drop cascades to table graph1._ag_label_edge
+NOTICE: graph "graph1" has been dropped
+ drop_graph
+------------
+
+(1 row)
+
+SELECT graph_exists('graph1');
+ graph_exists
+--------------
+ false
+(1 row)
+
+SELECT raise_notice('graph1');
+NOTICE: graph does not exist
+ raise_notice
+--------------
+
+(1 row)
+
+DROP FUNCTION raise_notice(TEXT);
-- dropping the graph
SELECT drop_graph('graph', true);
NOTICE: drop cascades to 2 other objects
diff --git a/regress/sql/catalog.sql b/regress/sql/catalog.sql
index 96c63e47..85fc4e8a 100644
--- a/regress/sql/catalog.sql
+++ b/regress/sql/catalog.sql
@@ -166,7 +166,32 @@ SELECT create_elabel(NULL, 'r');
SELECT create_vlabel(NULL, NULL);
SELECT create_elabel(NULL, NULL);
+-- age_graph_exists()
+CREATE FUNCTION raise_notice(graph_name TEXT)
+RETURNS void AS $$
+DECLARE
+ res BOOLEAN;
+BEGIN
+ -- this tests whether graph_exists works with IF-ELSE.
+ SELECT graph_exists('graph1') INTO res;
+ IF res THEN
+ RAISE NOTICE 'graph exists';
+ ELSE
+ RAISE NOTICE 'graph does not exist';
+ END IF;
+END $$ LANGUAGE plpgsql;
+
+SELECT graph_exists('graph1');
+
+SELECT create_graph('graph1');
+SELECT graph_exists('graph1');
+SELECT raise_notice('graph1');
+
+SELECT drop_graph('graph1', true);
+SELECT graph_exists('graph1');
+SELECT raise_notice('graph1');
+
+DROP FUNCTION raise_notice(TEXT);
+
-- dropping the graph
SELECT drop_graph('graph', true);
-
-
diff --git a/sql/age_agtype.sql b/sql/age_agtype.sql
index 944508dd..a6932cb1 100644
--- a/sql/age_agtype.sql
+++ b/sql/age_agtype.sql
@@ -1060,3 +1060,7 @@ CREATE OPERATOR CLASS graphid_ops_hash
OPERATOR 1 =,
FUNCTION 1 ag_catalog.graphid_hash_cmp(graphid);
+CREATE FUNCTION ag_catalog.graph_exists(graph_name name)
+ RETURNS agtype
+ LANGUAGE c
+ AS 'MODULE_PATHNAME', 'age_graph_exists';
diff --git a/src/backend/commands/graph_commands.c
b/src/backend/commands/graph_commands.c
index a558d298..3d51e67a 100644
--- a/src/backend/commands/graph_commands.c
+++ b/src/backend/commands/graph_commands.c
@@ -109,7 +109,34 @@ Datum create_graph(PG_FUNCTION_ARGS)
(errmsg("graph \"%s\" has been created", NameStr(*graph_name))));
/* according to postgres specification of c-language functions if function
returns void this is the syntax */
- PG_RETURN_VOID();
+ PG_RETURN_VOID();
+}
+
+PG_FUNCTION_INFO_V1(age_graph_exists);
+
+Datum age_graph_exists(PG_FUNCTION_ARGS)
+{
+ Name graph_name;
+ char *graph_name_str;
+
+ /* if no argument is passed with the function, graph name cannot be null */
+ if (PG_ARGISNULL(0))
+ {
+ ereport(ERROR, (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ errmsg("graph name can not be NULL")));
+ }
+
+ graph_name = PG_GETARG_NAME(0);
+ graph_name_str = NameStr(*graph_name);
+
+ if (graph_exists(graph_name_str))
+ {
+ return boolean_to_agtype(true);
+ }
+ else
+ {
+ return boolean_to_agtype(false);
+ }
}
static Oid create_schema_for_graph(const Name graph_name)
