Implement EXISTS subquery for CASE (#1345)
Modified logic of EXISTS to wrap itself in a agtype cast. This
allows EXISTS to work with in CASE statements, among other
implementations that may require an agtype.
Also renamed the wrapper function to be more generic to denote
its usage in other implementations if need be.
Added regression tests for EXISTS
diff --git a/regress/expected/expr.out b/regress/expected/expr.out
index d725722..43b4080 100644
--- a/regress/expected/expr.out
+++ b/regress/expected/expr.out
@@ -6514,8 +6514,8 @@
WHEN 1 THEN count(*)
ELSE 'not count'
END
-$$ ) AS (j agtype, case_statement agtype);
- j | case_statement
+$$ ) AS (n agtype, case_statement agtype);
+ n | case_statement
------------------------------------------------------------------------------------------------+----------------
{"id": 281474976710658, "label": "", "properties": {"i": "a", "j": "b", "id": 2}}::vertex | "not count"
{"id": 281474976710661, "label": "", "properties": {"i": [], "j": [0, 1, 2], "id": 5}}::vertex | "not count"
@@ -6532,8 +6532,8 @@
WHEN 1 THEN count(*)
ELSE 'not count'
END
-$$ ) AS (j agtype, case_statement agtype);
- j | case_statement
+$$ ) AS (n agtype, case_statement agtype);
+ n | case_statement
------------------------------------------------------------------------------------------------+----------------
{"id": 281474976710658, "label": "", "properties": {"i": "a", "j": "b", "id": 2}}::vertex | "not count"
{"id": 281474976710661, "label": "", "properties": {"i": [], "j": [0, 1, 2], "id": 5}}::vertex | "not count"
@@ -6550,8 +6550,8 @@
WHEN 1 THEN count(n)
ELSE 'not count'
END
-$$ ) AS (j agtype, case_statement agtype);
- j | case_statement
+$$ ) AS (n agtype, case_statement agtype);
+ n | case_statement
------------------------------------------------------------------------------------------------+----------------
{"id": 281474976710658, "label": "", "properties": {"i": "a", "j": "b", "id": 2}}::vertex | "not count"
{"id": 281474976710661, "label": "", "properties": {"i": [], "j": [0, 1, 2], "id": 5}}::vertex | "not count"
@@ -6568,8 +6568,8 @@
WHEN 1 THEN count(n)
ELSE 'not count'
END
-$$ ) AS (j agtype, case_statement agtype);
- j | case_statement
+$$ ) AS (n agtype, case_statement agtype);
+ n | case_statement
------------------------------------------------------------------------------------------------+----------------
{"id": 281474976710658, "label": "", "properties": {"i": "a", "j": "b", "id": 2}}::vertex | "not count"
{"id": 281474976710661, "label": "", "properties": {"i": [], "j": [0, 1, 2], "id": 5}}::vertex | "not count"
@@ -6586,8 +6586,8 @@
WHEN 1 THEN count(1)
ELSE 'not count'
END
-$$ ) AS (j agtype, case_statement agtype);
- j | case_statement
+$$ ) AS (n agtype, case_statement agtype);
+ n | case_statement
------------------------------------------------------------------------------------------------+----------------
{"id": 281474976710658, "label": "", "properties": {"i": "a", "j": "b", "id": 2}}::vertex | "not count"
{"id": 281474976710661, "label": "", "properties": {"i": [], "j": [0, 1, 2], "id": 5}}::vertex | "not count"
@@ -6604,8 +6604,8 @@
WHEN 1 THEN count(1)
ELSE 'not count'
END
-$$ ) AS (j agtype, case_statement agtype);
- j | case_statement
+$$ ) AS (n agtype, case_statement agtype);
+ n | case_statement
------------------------------------------------------------------------------------------------+----------------
{"id": 281474976710658, "label": "", "properties": {"i": "a", "j": "b", "id": 2}}::vertex | "not count"
{"id": 281474976710661, "label": "", "properties": {"i": [], "j": [0, 1, 2], "id": 5}}::vertex | "not count"
@@ -6615,6 +6615,72 @@
{"id": 281474976710662, "label": "", "properties": {"i": {}, "j": {"i": 1}, "id": 6}}::vertex | "not count"
(6 rows)
+--CASE with EXISTS()
+--exists(n.property)
+SELECT * FROM cypher('case_statement', $$
+ MATCH (n)
+ RETURN n, CASE exists(n.j)
+ WHEN true THEN 'property j exists'
+ ELSE 'property j does not exist'
+ END
+$$ ) AS (n agtype, case_statement agtype);
+ n | case_statement
+------------------------------------------------------------------------------------------------+-----------------------------
+ {"id": 281474976710657, "label": "", "properties": {"i": 1, "id": 1}}::vertex | "property j does not exist"
+ {"id": 281474976710658, "label": "", "properties": {"i": "a", "j": "b", "id": 2}}::vertex | "property j exists"
+ {"id": 281474976710659, "label": "", "properties": {"i": 0, "j": 1, "id": 3}}::vertex | "property j exists"
+ {"id": 281474976710660, "label": "", "properties": {"i": true, "j": false, "id": 4}}::vertex | "property j exists"
+ {"id": 281474976710661, "label": "", "properties": {"i": [], "j": [0, 1, 2], "id": 5}}::vertex | "property j exists"
+ {"id": 281474976710662, "label": "", "properties": {"i": {}, "j": {"i": 1}, "id": 6}}::vertex | "property j exists"
+(6 rows)
+
+--CASE evaluates to boolean true, is not a boolean, should hit ELSE
+SELECT * FROM cypher('case_statement', $$
+ MATCH (n)
+ RETURN n, CASE exists(n.j)
+ WHEN 1 THEN 'should not output me'
+ ELSE '1 is not a boolean'
+ END
+$$ ) AS (n agtype, case_statement agtype);
+ n | case_statement
+------------------------------------------------------------------------------------------------+----------------------
+ {"id": 281474976710657, "label": "", "properties": {"i": 1, "id": 1}}::vertex | "1 is not a boolean"
+ {"id": 281474976710658, "label": "", "properties": {"i": "a", "j": "b", "id": 2}}::vertex | "1 is not a boolean"
+ {"id": 281474976710659, "label": "", "properties": {"i": 0, "j": 1, "id": 3}}::vertex | "1 is not a boolean"
+ {"id": 281474976710660, "label": "", "properties": {"i": true, "j": false, "id": 4}}::vertex | "1 is not a boolean"
+ {"id": 281474976710661, "label": "", "properties": {"i": [], "j": [0, 1, 2], "id": 5}}::vertex | "1 is not a boolean"
+ {"id": 281474976710662, "label": "", "properties": {"i": {}, "j": {"i": 1}, "id": 6}}::vertex | "1 is not a boolean"
+(6 rows)
+
+--exists in WHEN, vacuously false because exists(n.j) evaluates to a boolean, n is a vertex
+SELECT * FROM cypher('case_statement', $$
+ MATCH (n)
+ RETURN n, CASE n
+ WHEN exists(n.j) THEN 'should not output me'
+ ELSE 'n is a vertex, not a boolean'
+ END
+$$ ) AS (j agtype, case_statement agtype);
+ j | case_statement
+------------------------------------------------------------------------------------------------+--------------------------------
+ {"id": 281474976710657, "label": "", "properties": {"i": 1, "id": 1}}::vertex | "n is a vertex, not a boolean"
+ {"id": 281474976710658, "label": "", "properties": {"i": "a", "j": "b", "id": 2}}::vertex | "n is a vertex, not a boolean"
+ {"id": 281474976710659, "label": "", "properties": {"i": 0, "j": 1, "id": 3}}::vertex | "n is a vertex, not a boolean"
+ {"id": 281474976710660, "label": "", "properties": {"i": true, "j": false, "id": 4}}::vertex | "n is a vertex, not a boolean"
+ {"id": 281474976710661, "label": "", "properties": {"i": [], "j": [0, 1, 2], "id": 5}}::vertex | "n is a vertex, not a boolean"
+ {"id": 281474976710662, "label": "", "properties": {"i": {}, "j": {"i": 1}, "id": 6}}::vertex | "n is a vertex, not a boolean"
+(6 rows)
+
+--exists(*) (should fail)
+SELECT * FROM cypher('case_statement', $$
+ MATCH (n)
+ RETURN n, CASE n.j
+ WHEN 1 THEN exists(*)
+ ELSE 'not count'
+ END
+$$ ) AS (j agtype, case_statement agtype);
+ERROR: syntax error at or near "*"
+LINE 4: WHEN 1 THEN exists(*)
+ ^
-- RETURN * and (u)--(v) optional forms
SELECT create_graph('opt_forms');
NOTICE: graph "opt_forms" has been created
diff --git a/regress/sql/expr.sql b/regress/sql/expr.sql
index 0aa62a0..6f7c585 100644
--- a/regress/sql/expr.sql
+++ b/regress/sql/expr.sql
@@ -2726,7 +2726,7 @@
WHEN 1 THEN count(*)
ELSE 'not count'
END
-$$ ) AS (j agtype, case_statement agtype);
+$$ ) AS (n agtype, case_statement agtype);
--concatenated
SELECT * FROM cypher('case_statement', $$
@@ -2735,7 +2735,7 @@
WHEN 1 THEN count(*)
ELSE 'not count'
END
-$$ ) AS (j agtype, case_statement agtype);
+$$ ) AS (n agtype, case_statement agtype);
--count(n)
SELECT * FROM cypher('case_statement', $$
@@ -2744,7 +2744,7 @@
WHEN 1 THEN count(n)
ELSE 'not count'
END
-$$ ) AS (j agtype, case_statement agtype);
+$$ ) AS (n agtype, case_statement agtype);
--concatenated
SELECT * FROM cypher('case_statement', $$
@@ -2753,7 +2753,7 @@
WHEN 1 THEN count(n)
ELSE 'not count'
END
-$$ ) AS (j agtype, case_statement agtype);
+$$ ) AS (n agtype, case_statement agtype);
--count(1)
SELECT * FROM cypher('case_statement', $$
@@ -2762,7 +2762,7 @@
WHEN 1 THEN count(1)
ELSE 'not count'
END
-$$ ) AS (j agtype, case_statement agtype);
+$$ ) AS (n agtype, case_statement agtype);
--concatenated
SELECT * FROM cypher('case_statement', $$
@@ -2771,8 +2771,48 @@
WHEN 1 THEN count(1)
ELSE 'not count'
END
+$$ ) AS (n agtype, case_statement agtype);
+
+--CASE with EXISTS()
+
+--exists(n.property)
+SELECT * FROM cypher('case_statement', $$
+ MATCH (n)
+ RETURN n, CASE exists(n.j)
+ WHEN true THEN 'property j exists'
+ ELSE 'property j does not exist'
+ END
+$$ ) AS (n agtype, case_statement agtype);
+
+--CASE evaluates to boolean true, is not a boolean, should hit ELSE
+SELECT * FROM cypher('case_statement', $$
+ MATCH (n)
+ RETURN n, CASE exists(n.j)
+ WHEN 1 THEN 'should not output me'
+ ELSE '1 is not a boolean'
+ END
+$$ ) AS (n agtype, case_statement agtype);
+
+--exists in WHEN, vacuously false because exists(n.j) evaluates to a boolean, n is a vertex
+SELECT * FROM cypher('case_statement', $$
+ MATCH (n)
+ RETURN n, CASE n
+ WHEN exists(n.j) THEN 'should not output me'
+ ELSE 'n is a vertex, not a boolean'
+ END
$$ ) AS (j agtype, case_statement agtype);
+--exists(*) (should fail)
+SELECT * FROM cypher('case_statement', $$
+ MATCH (n)
+ RETURN n, CASE n.j
+ WHEN 1 THEN exists(*)
+ ELSE 'not count'
+ END
+$$ ) AS (j agtype, case_statement agtype);
+
+
+
-- RETURN * and (u)--(v) optional forms
SELECT create_graph('opt_forms');
diff --git a/src/backend/parser/cypher_gram.y b/src/backend/parser/cypher_gram.y
index 6ba8cc6..4f7fddf 100644
--- a/src/backend/parser/cypher_gram.y
+++ b/src/backend/parser/cypher_gram.y
@@ -227,7 +227,7 @@
static Node *make_function_expr(List *func_name, List *exprs, int location);
static Node *make_star_function_expr(List *func_name, List *exprs, int location);
static Node *make_distinct_function_expr(List *func_name, List *exprs, int location);
-static FuncCall *wrap_pg_funccall_to_agtype(Node* fnode, char *type, int location);
+static FuncCall *node_to_agtype(Node* fnode, char *type, int location);
// setops
static Node *make_set_op(SetOperation op, bool all_or_distinct, List *larg,
@@ -1742,12 +1742,16 @@
n->operName = NIL;
n->subselect = (Node *) sub;
n->location = @1;
- $$ = (Node *) n;
+ $$ = (Node *)node_to_agtype((Node *)n, "boolean", @1);
}
| EXISTS '(' property_value ')'
{
- $$ = make_function_expr(list_make1(makeString("exists")),
- list_make1($3), @2);
+ FuncCall *n;
+ n = makeFuncCall(list_make1(makeString("exists")),
+ list_make1($3), COERCE_SQL_SYNTAX, @2);
+
+ $$ = (Node *)node_to_agtype((Node *)n, "boolean", @2);
+
}
;
@@ -2289,7 +2293,7 @@
fnode = makeFuncCall(funcname, exprs, COERCE_SQL_SYNTAX, location);
/* build the cast to wrap the function call to return agtype. */
- fnode = wrap_pg_funccall_to_agtype((Node *)fnode, "integer", location);
+ fnode = node_to_agtype((Node *)fnode, "integer", location);
return (Node *)fnode;
}
@@ -2345,7 +2349,7 @@
fnode->agg_star = true;
/* build the cast to wrap the function call to return agtype. */
- fnode = wrap_pg_funccall_to_agtype((Node *)fnode, "integer", location);
+ fnode = node_to_agtype((Node *)fnode, "integer", location);
return (Node *)fnode;
}
@@ -2403,7 +2407,7 @@
fnode->agg_distinct = true;
/* build the cast to wrap the function call to return agtype. */
- fnode = wrap_pg_funccall_to_agtype((Node *)fnode, "integer", location);
+ fnode = node_to_agtype((Node *)fnode, "integer", location);
return (Node *)fnode;
}
else
@@ -2434,7 +2438,7 @@
* helper function to wrap pg_function in the appropiate typecast function to
* interface with AGE components
*/
-static FuncCall *wrap_pg_funccall_to_agtype(Node * fnode, char *type, int location)
+static FuncCall *node_to_agtype(Node * fnode, char *type, int location)
{
List *funcname = list_make1(makeString("ag_catalog"));
