Support one vertex in match with no variable name or label

Author: JoshInnis

regress/expected/cypher_create.out

@@ -32,9 +32,29 @@ USE GRAPH cypher_create;
 (1 row)
 
 CREATE ();
-ERROR:  unexpected Node for cypher_clause
+WARNING:  relcache reference leak: relation "_ag_label_vertex" not closed
+--
+(0 rows)
+
+SELECT * FROM cypher_create._ag_label_vertex;
+       id        | properties 
+-----------------+------------
+ 281474976710657 | 
+(1 row)
+
+MATCH () RETURN 1;
+ ?column? 
+----------
+ 1
+(1 row)
+
 CREATE ()-[]->();
-ERROR:  unexpected Node for cypher_clause
+ERROR:  CREATE doesn't work with paths
+CYPHER WITH 1 as a
+CREATE ();
+ERROR:  CREATE doesn't work with previous clauses
+CREATE () RETURN 1 as a;
+ERROR:  CREATE doesn't work with next clauses
 --
 -- Clean up
 --

regress/sql/cypher_create.sql

@@ -25,9 +25,17 @@ CREATE GRAPH cypher_create;
 USE GRAPH cypher_create;
 
 CREATE ();
+SELECT * FROM cypher_create._ag_label_vertex;
+
+MATCH () RETURN 1;
 
 CREATE ()-[]->();
 
+CYPHER WITH 1 as a
+CREATE ();
+
+CREATE () RETURN 1 as a;
+
 --
 -- Clean up
 --

src/backend/catalog/ag_label.c

@@ -45,12 +45,6 @@
 #include "utils/ag_cache.h"
 #include "utils/graphid.h"
 
-
-
-
-static ResultRelInfo *create_entity_result_rel_info(EState *estate, char *graph_name,
-                                             char *label_name);
-
 PG_FUNCTION_INFO_V1(ltree_in);
 PG_FUNCTION_INFO_V1(ltree_addltree);
 
@@ -282,111 +276,4 @@ RangeVar *get_label_range_var(char *graph_name, Oid graph_oid,
     return makeRangeVar(graph_name, relname, 2);
 }
 
-#include "parser/parse_node.h"
-/*
- * Given the graph name and the label name, create a ResultRelInfo for the table
- * those to variables represent. Open the Indices too.
- */
-ResultRelInfo *create_entity_result_rel_info(EState *estate, char *graph_name,
-                                             char *label_name)
-{
-    RangeVar *rv;
-    Relation label_relation;
-    ResultRelInfo *resultRelInfo;
-
-    ParseState *pstate = make_parsestate(NULL);
-
-    resultRelInfo = palloc(sizeof(ResultRelInfo));
-
-    if (strlen(label_name) == 0)
-    {
-        rv = makeRangeVar(graph_name, AG_DEFAULT_LABEL_VERTEX, -1);
-    }
-    else
-    {
-        rv = makeRangeVar(graph_name, label_name, -1);
-    }
-
-    label_relation = parserOpenTable(pstate, rv, RowExclusiveLock);
-
-    // initialize the resultRelInfo
-    InitResultRelInfo(resultRelInfo, label_relation,
-                      list_length(estate->es_range_table), NULL,
-                      estate->es_instrument);
-
-    // open the parse state
-    ExecOpenIndices(resultRelInfo, false);
-
-    free_parsestate(pstate);
-
-    return resultRelInfo;
-}
-
 
-/*
- * Retrieves a list of all the names of a graph.
- *
- * XXX: We may want to use the cache system for this function,
- * however the cache system currently requires us to know the
- * name of the label we want.
- */
-List *get_all_edge_labels_per_graph(EState *estate, Oid graph_oid)
-{
-    List *labels = NIL;
-    ScanKeyData scan_keys[2];
-    Relation ag_label;
-    TableScanDesc scan_desc;
-    HeapTuple tuple;
-    TupleTableSlot *slot;
-    ResultRelInfo *resultRelInfo;
-
-    // setup scan keys to get all edges for the given graph oid
-    ScanKeyInit(&scan_keys[1], Anum_ag_label_graph, BTEqualStrategyNumber,
-                F_OIDEQ, ObjectIdGetDatum(graph_oid));
-    ScanKeyInit(&scan_keys[0], Anum_ag_label_kind, BTEqualStrategyNumber,
-                F_CHAREQ, CharGetDatum(LABEL_TYPE_EDGE));
-
-    // setup the table to be scanned
-    ag_label = table_open(ag_label_relation_id(), RowExclusiveLock);
-    scan_desc = table_beginscan(ag_label, estate->es_snapshot, 2, scan_keys);
-
-    resultRelInfo = create_entity_result_rel_info(estate, CATALOG_SCHEMA,
-                                                  "ag_label");
-
-    slot = ExecInitExtraTupleSlot(
-        estate, RelationGetDescr(resultRelInfo->ri_RelationDesc),
-        &TTSOpsHeapTuple);
-
-    // scan through the results and get all the label names.
-    while(true)
-    {
-        Name label;
-        bool isNull;
-        Datum datum;
-
-        tuple = heap_getnext(scan_desc, ForwardScanDirection);
-
-        // no more labels to process
-        if (!HeapTupleIsValid(tuple))
-            break;
-
-        ExecStoreHeapTuple(tuple, slot, false);
-
-        datum = slot_getattr(slot, Anum_ag_label_name, &isNull);
-        label = DatumGetName(datum);
-
-        labels = lappend(labels, label);
-    }
-
-    table_endscan(scan_desc);
-
-    // close the indices
-    ExecCloseIndices(resultRelInfo);
-
-    // close the rel
-    table_close(resultRelInfo->ri_RelationDesc, RowExclusiveLock);
-
-    table_close(resultRelInfo->ri_RelationDesc, RowExclusiveLock);
-
-    return labels;
-}

src/backend/commands/graph_commands.c

@@ -188,10 +188,6 @@ Datum create_graph(PG_FUNCTION_ARGS)
         ereport(ERROR, (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
                         errmsg("graph name must not be NULL")));
 
-    /*
-    graph_name = PG_GETARG_NAME(0);
-
-    graph_name_str = NameStr(*graph_name);*/
     graph_name_str =  TextDatumGetCString(PG_GETARG_DATUM(0));
     if (graph_exists(graph_name_str))
         ereport(ERROR,

src/backend/commands/label_commands.c

@@ -788,7 +788,7 @@ static List *create_vertex_table_elements(char *graph_name, char *label_name,
     // "properties" gtype NOT NULL DEFAULT CATALOG_SCHEMA."gtype_build_map"()
     props = makeColumnDef(AG_VERTEX_COLNAME_PROPERTIES, GTYPEOID, -1,
                           InvalidOid);
-    props->constraints = list_make2(build_not_null_constraint(),
+    props->constraints = list_make2(build_null_constraint(),
                                     build_properties_default());
 
     return list_make2(id, props);