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JoshInnisJoshInnis
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Support Pattern Comprehensions in Read Clauses
Support only in WHERE, WITH and RETURN for now... Honestly, Thought that would be harder to support.
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+217
-13
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4 files changed

+217
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‎regress/expected/cypher_match.out‎

Lines changed: 105 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -1584,6 +1584,97 @@ CYPHER WITH (SELECT i FROM tst LIMIT 1) as a RETURN a;
15841584
1
15851585
(1 row)
15861586

1587+
CREATE GRAPH keanu;
1588+
NOTICE: graph "keanu" has been created
1589+
create_graph
1590+
--------------
1591+
1592+
(1 row)
1593+
1594+
USE GRAPH keanu;
1595+
use_graph
1596+
-----------
1597+
1598+
(1 row)
1599+
1600+
CREATE
1601+
(keanu:Person {name: 'Keanu Reeves'}),
1602+
(johnnyMnemonic:Movie {title: 'Johnny Mnemonic', released: 1995}),
1603+
(theMatrixRevolutions:Movie {title: 'The Matrix Revolutions', released: 2003}),
1604+
(theMatrixReloaded:Movie {title: 'The Matrix Reloaded', released: 2003}),
1605+
(theReplacements:Movie {title: 'The Replacements', released: 2000}),
1606+
(theMatrix:Movie {title: 'The Matrix', released: 1999}),
1607+
(theDevilsAdvocate:Movie {title: 'The Devils Advocate', released: 1997}),
1608+
(theMatrixResurrections:Movie {title: 'The Matrix Resurrections', released: 2021}),
1609+
(keanu)-[:ACTED_IN]->(johnnyMnemonic),
1610+
(keanu)-[:ACTED_IN]->(theMatrixRevolutions),
1611+
(keanu)-[:ACTED_IN]->(theMatrixReloaded),
1612+
(keanu)-[:ACTED_IN]->(theReplacements),
1613+
(keanu)-[:ACTED_IN]->(theMatrix),
1614+
(keanu)-[:ACTED_IN]->(theDevilsAdvocate),
1615+
(keanu)-[:ACTED_IN]->(theMatrixResurrections);
1616+
--
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(0 rows)
1618+
1619+
--MATCH (keanu:Person {name: 'Keanu Reeves'})
1620+
--RETURN [MATCH (keanu) WHERE 1=1 | 1] AS years;
1621+
CYPHER WITH [MATCH (keanu:Person {name: 'Keanu Reeves'})-[:ACTED_IN]->(b) WHERE b.title CONTAINS 'Matrix' RETURN b.released] AS years
1622+
RETURN years;
1623+
years
1624+
--------------------------
1625+
[2003, 2003, 1999, 2021]
1626+
(1 row)
1627+
1628+
MATCH (keanu:Person {name: 'Keanu Reeves'})
1629+
RETURN [
1630+
MATCH (keanu)-[:ACTED_IN]->(b) WHERE b.title CONTAINS 'Matrix' RETURN b.released
1631+
] AS years;
1632+
years
1633+
--------------------------
1634+
[2003, 2003, 1999, 2021]
1635+
(1 row)
1636+
1637+
CREATE (test:Years {years: [MATCH (keanu)-[:ACTED_IN]->(b) WHERE b.title CONTAINS 'Matrix' RETURN b.released]})
1638+
RETURN test;
1639+
ERROR: cannot handle unplanned sub-select
1640+
CREATE (test:Years2);
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--
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(0 rows)
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1644+
MATCH (test:Years2)
1645+
SET test.years = [MATCH (keanu)-[:ACTED_IN]->(b) WHERE b.title CONTAINS 'Matrix' RETURN b.released]
1646+
RETURN test;
1647+
ERROR: cannot handle unplanned sub-select
1648+
MATCH (test {years: [MATCH (keanu)-[:ACTED_IN]->(b) WHERE b.title CONTAINS 'Matrix' RETURN b.released]})
1649+
RETURN test;
1650+
test
1651+
------
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(0 rows)
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1654+
MATCH (test)
1655+
WHERE test.years = [MATCH (keanu)-[:ACTED_IN]->(b) WHERE b.title CONTAINS 'Matrix' RETURN b.released]
1656+
RETURN test;
1657+
test
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------
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(0 rows)
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RETURN case when false then '' else [MATCH (keanu:Person {name: 'Keanu Reeves'})-[:ACTED_IN]->(b) WHERE b.title CONTAINS 'Matrix' RETURN b.released] end AS years;
1662+
years
1663+
--------------------------
1664+
[2003, 2003, 1999, 2021]
1665+
(1 row)
1666+
1667+
/*
1668+
MATCH (keanu:Person {name: 'Keanu Reeves'})
1669+
RETURN [(MATCH (keanu)-[:ACTED_IN]->(b)) WHERE b.title CONTAINS 'Matrix' | b.released] AS years;
1670+
1671+
MATCH (keanu:Person {name: 'Keanu Reeves'})
1672+
RETURN [(keanu)-[]->(b:Movie) WHERE b.title CONTAINS 'Matrix' | b.released] AS years;
1673+
1674+
1675+
MATCH (keanu:Person {name: 'Keanu Reeves'})
1676+
RETURN [(:Person)-[]->(b:Movie) WHERE b.title = 'The Matrix' | b.released] AS years;
1677+
*/
15871678
--
15881679
-- Clean up
15891680
--
@@ -1611,6 +1702,20 @@ NOTICE: graph "cypher_match" has been dropped
16111702

16121703
(1 row)
16131704

1705+
DROP GRAPH keanu CASCADE;
1706+
NOTICE: drop cascades to 6 other objects
1707+
DETAIL: drop cascades to table keanu._ag_label_vertex
1708+
drop cascades to table keanu._ag_label_edge
1709+
drop cascades to table keanu.person
1710+
drop cascades to table keanu.movie
1711+
drop cascades to table keanu.acted_in
1712+
drop cascades to table keanu.years2
1713+
NOTICE: graph "keanu" has been dropped
1714+
drop_graph
1715+
------------
1716+
1717+
(1 row)
1718+
16141719
--
16151720
-- End
16161721
--

‎regress/sql/cypher_match.sql‎

Lines changed: 64 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -355,10 +355,74 @@ RETURN (SELECT COUNT(*) FROM tst);
355355
CYPHER WITH (RETURN 1) as a RETURN a;
356356
CYPHER WITH (SELECT i FROM tst LIMIT 1) as a RETURN a;
357357

358+
CREATE GRAPH keanu;
359+
USE GRAPH keanu;
360+
361+
CREATE
362+
(keanu:Person {name: 'Keanu Reeves'}),
363+
(johnnyMnemonic:Movie {title: 'Johnny Mnemonic', released: 1995}),
364+
(theMatrixRevolutions:Movie {title: 'The Matrix Revolutions', released: 2003}),
365+
(theMatrixReloaded:Movie {title: 'The Matrix Reloaded', released: 2003}),
366+
(theReplacements:Movie {title: 'The Replacements', released: 2000}),
367+
(theMatrix:Movie {title: 'The Matrix', released: 1999}),
368+
(theDevilsAdvocate:Movie {title: 'The Devils Advocate', released: 1997}),
369+
(theMatrixResurrections:Movie {title: 'The Matrix Resurrections', released: 2021}),
370+
(keanu)-[:ACTED_IN]->(johnnyMnemonic),
371+
(keanu)-[:ACTED_IN]->(theMatrixRevolutions),
372+
(keanu)-[:ACTED_IN]->(theMatrixReloaded),
373+
(keanu)-[:ACTED_IN]->(theReplacements),
374+
(keanu)-[:ACTED_IN]->(theMatrix),
375+
(keanu)-[:ACTED_IN]->(theDevilsAdvocate),
376+
(keanu)-[:ACTED_IN]->(theMatrixResurrections);
377+
378+
--MATCH (keanu:Person {name: 'Keanu Reeves'})
379+
--RETURN [MATCH (keanu) WHERE 1=1 | 1] AS years;
380+
381+
CYPHER WITH [MATCH (keanu:Person {name: 'Keanu Reeves'})-[:ACTED_IN]->(b) WHERE b.title CONTAINS 'Matrix' RETURN b.released] AS years
382+
RETURN years;
383+
384+
MATCH (keanu:Person {name: 'Keanu Reeves'})
385+
RETURN [
386+
MATCH (keanu)-[:ACTED_IN]->(b) WHERE b.title CONTAINS 'Matrix' RETURN b.released
387+
] AS years;
388+
389+
CREATE (test:Years {years: [MATCH (keanu)-[:ACTED_IN]->(b) WHERE b.title CONTAINS 'Matrix' RETURN b.released]})
390+
RETURN test;
391+
392+
393+
CREATE (test:Years2);
394+
395+
MATCH (test:Years2)
396+
SET test.years = [MATCH (keanu)-[:ACTED_IN]->(b) WHERE b.title CONTAINS 'Matrix' RETURN b.released]
397+
RETURN test;
398+
399+
400+
MATCH (test {years: [MATCH (keanu)-[:ACTED_IN]->(b) WHERE b.title CONTAINS 'Matrix' RETURN b.released]})
401+
RETURN test;
402+
403+
MATCH (test)
404+
WHERE test.years = [MATCH (keanu)-[:ACTED_IN]->(b) WHERE b.title CONTAINS 'Matrix' RETURN b.released]
405+
RETURN test;
406+
407+
RETURN case when false then '' else [MATCH (keanu:Person {name: 'Keanu Reeves'})-[:ACTED_IN]->(b) WHERE b.title CONTAINS 'Matrix' RETURN b.released] end AS years;
408+
409+
410+
/*
411+
MATCH (keanu:Person {name: 'Keanu Reeves'})
412+
RETURN [(MATCH (keanu)-[:ACTED_IN]->(b)) WHERE b.title CONTAINS 'Matrix' | b.released] AS years;
413+
414+
MATCH (keanu:Person {name: 'Keanu Reeves'})
415+
RETURN [(keanu)-[]->(b:Movie) WHERE b.title CONTAINS 'Matrix' | b.released] AS years;
416+
417+
418+
MATCH (keanu:Person {name: 'Keanu Reeves'})
419+
RETURN [(:Person)-[]->(b:Movie) WHERE b.title = 'The Matrix' | b.released] AS years;
420+
*/
358421
--
359422
-- Clean up
360423
--
361424
DROP GRAPH cypher_match CASCADE;
425+
DROP GRAPH keanu CASCADE;
362426

363427
--
364428
-- End

‎src/backend/parser/ag_scanner.l‎

Lines changed: 1 addition & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -1297,8 +1297,7 @@ ag_token token;
12971297
} if (yyleng == 1)
12981298
if ('-' == yytext[0] || '=' == yytext[0] || '<' == yytext[0] ||
12991299
'>' == yytext[0] || '*' == yytext[0] || '^' == yytext[0] ||
1300-
'%' == yytext[0] || '/' == yytext[0] || '+' == yytext[0] ||
1301-
'-' == yytext[0]) {
1300+
'%' == yytext[0] || '/' == yytext[0] || '+' == yytext[0]) {
13021301
token.type = AG_TOKEN_CHAR;
13031302
token.value.c = yytext[0];
13041303
token.location = get_location();

‎src/backend/parser/cypher_gram.y‎

Lines changed: 47 additions & 11 deletions
Original file line numberDiff line numberDiff line change
@@ -17920,13 +17920,7 @@ cypher_expr_atom:
1792017920
else
1792117921
$$ = $2;
1792217922
}
17923-
| '[' anonymous_path where_clause '|' return_item_list ']' %prec '['
17924-
{
17925-
ereport(ERROR, errmsg("pattern comprehensions are not yet implemented"));
17926-
17927-
$$ = NULL;
17928-
}
17929-
| '[' ColId IN cypher_a_expr cypher_where_opt '|' return_item ']' %prec '['
17923+
/*| '[' ColId IN cypher_a_expr cypher_where_opt '|' return_item ']' %prec '['
1793017924
{
1793117925
ereport(ERROR, errmsg("list comprehensions are not yet implemented"));
1793217926
@@ -17935,7 +17929,7 @@ cypher_expr_atom:
1793517929
| cypher_var_name '{' map_proj_list_opt '}' %prec '{'
1793617930
{
1793717931
ereport(ERROR, errmsg("map projections are not yet implemented"));
17938-
}
17932+
}*/
1793917933
| expr_case
1794017934
| cypher_expr_func
1794117935
| '(' cypher_query ')' %prec UNARY_MINUS
@@ -18117,11 +18111,53 @@ map_keyval_list:
1811718111
;
1811818112

1811918113
list:
18120-
'[' cypher_expr_list_opt ']'
18114+
'[' cypher_stmt ']' %prec '.'
18115+
{
18116+
//cypher_pattern_comprehension *comp = make_ag_node(cypher_pattern_comprehension);
18117+
18118+
//comp->pattern = $2;
18119+
cypher_return *ret = llast($2);
18120+
if (!is_ag_node(ret, cypher_return))
18121+
ereport(ERROR, errmsg("Pattern Comprehensions must end with a return"));
18122+
18123+
if (list_length(ret->items) != 1)
18124+
ereport(ERROR, errmsg("RETURN clause for Pattern Comprehensions can only contain one item"));
18125+
18126+
ResTarget *res = linitial(ret->items);
18127+
res->val = (Node *)makeFuncCall(list_make2(makeString("postgraph"), makeString("collect")), list_make1(res->val), COERCE_SQL_SYNTAX, @1);
18128+
18129+
18130+
cypher_sub_pattern *sub;
18131+
18132+
sub = make_ag_node(cypher_sub_pattern);
18133+
sub->pattern = $2;
18134+
sub->kind = CSP_EXISTS;
18135+
18136+
SubLink *n = makeNode(SubLink);
18137+
n->subLinkType = EXPR_SUBLINK;
18138+
n->subLinkId = 0;
18139+
n->testexpr = NULL;
18140+
n->operName = NIL;
18141+
n->subselect = sub;
18142+
n->location = @1;
18143+
$$ = (Node *)n;
18144+
18145+
}
18146+
/*| '[' anonymous_path where_clause '|' return_item_list ']' %prec '.'
18147+
{
18148+
cypher_pattern_comprehension *comp = make_ag_node(cypher_pattern_comprehension);
18149+
18150+
comp->pattern = $2;
18151+
comp->where = $3;
18152+
comp->return_list = $5;
18153+
comp->location = @1;
18154+
18155+
$$ = (Node *)comp;
18156+
}*/
18157+
| '[' cypher_expr_list_opt ']' %prec '['
1812118158
{
18122-
cypher_list *n;
18159+
cypher_list *n = make_ag_node(cypher_list);
1812318160

18124-
n = make_ag_node(cypher_list);
1812518161
n->elems = $2;
1812618162

1812718163
$$ = (Node *)n;

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