Fix missing space before WHERE in GRAPH_TABLE deparse

get_graph_pattern_def() emitted the pattern-level WHERE keyword as
"WHERE " with no leading space, so reverse-parsing produced output
like "(o IS orders)WHERE (...)".  The element-level WHERE deparse in
get_path_pattern_expr_def() already prepends a separating space; the
pattern-level branch was inconsistent with it.  Emit " WHERE " to
match.

The output still re-parses to the same tree, so this is cosmetic.

For test coverage, add a whole-pattern WHERE clause to the existing
customers_us view, which is already reverse-parsed with
pg_get_viewdef().

Author: Dhruv Chauhan <chauhandhruv351@gmail.com>
Reviewed-by: Ashutosh Bapat <ashutosh.bapat.oss@gmail.com>
Discussion: https://www.postgresql.org/message-id/flat/CANWwWcpHb0h7tg6otRnL-FV83jwQpAiyw1bhvv8T78kpwZ-0ow%40mail.gmail.com

diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c
index 908134594cb1a06d838d6300bc42f31dbbb09939..1d41c06201bbfc7df1630490ad74745f1ef56393 100644 (file)
--- a/src/backend/utils/adt/ruleutils.c
+++ b/src/backend/utils/adt/ruleutils.c
@@ -8135,7 +8135,7 @@ get_graph_pattern_def(GraphPattern *graph_pattern, deparse_context *context)
 
        if (graph_pattern->whereClause)
        {
-               appendStringInfoString(buf, "WHERE ");
+               appendStringInfoString(buf, " WHERE ");
                get_rule_expr(graph_pattern->whereClause, context, false);
        }
 }

diff --git a/src/test/regress/expected/graph_table.out b/src/test/regress/expected/graph_table.out
index 46566b2e32f682ece464fe5e42c3a31c2978ad48..b7a6182457d06b4fca7befd2267d7f8078976a49 100644 (file)
--- a/src/test/regress/expected/graph_table.out
+++ b/src/test/regress/expected/graph_table.out
@@ -965,13 +965,14 @@ SELECT * FROM GRAPH_TABLE (g4 MATCH (s WHERE s.id = 3)-[e]-(d) COLUMNS (s.val, e
 
 -- GRAPH_TABLE in views
 -- The query in the view definition is intentionally complex to test one view with many
--- features like label disjunction, lateral references, WHERE clauses in graph
--- patterns.
+-- features like label disjunction, lateral references, WHERE clauses on graph
+-- pattern elements as well as on the whole graph pattern.
 CREATE VIEW customers_us AS
 SELECT g.* FROM x1,
                 GRAPH_TABLE (myshop MATCH (c IS customers WHERE c.address = 'US' AND c.customer_id = x1.a)
                                           -[IS customer_orders | customer_wishlists ]->
                                           (l IS orders | wishlists)-[ IS list_items]->(p IS products)
+                                    WHERE p.price > 0
                                     COLUMNS (c.name AS customer_name, p.name AS product_name, p.price, x1.a AS a)) g
            ORDER BY customer_name, product_name;
 -- Dropping properties or labels used by a view is not allowed
@@ -993,14 +994,14 @@ DETAIL:  view customers_us depends on property price of property graph myshop
 HINT:  Use DROP ... CASCADE to drop the dependent objects too.
 -- ruleutils reverse parsing
 SELECT pg_get_viewdef('customers_us'::regclass);
-                                                                                                                                                 pg_get_viewdef                                                                                                                                                 
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
-  SELECT g.customer_name,                                                                                                                                                                                                                                                                                      +
-     g.product_name,                                                                                                                                                                                                                                                                                           +
-     g.price,                                                                                                                                                                                                                                                                                                  +
-     g.a                                                                                                                                                                                                                                                                                                       +
-    FROM x1,                                                                                                                                                                                                                                                                                                   +
-     GRAPH_TABLE (myshop MATCH (c IS customers WHERE (((c.address)::text = 'US'::text) AND (c.customer_id = x1.a)))-[IS customer_orders|customer_wishlists]->(l IS orders|wishlists)-[IS list_items]->(p IS products) COLUMNS (c.name AS customer_name, p.name AS product_name, p.price AS price, x1.a AS a)) g+
+                                                                                                                                                                pg_get_viewdef                                                                                                                                                                 
+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
+  SELECT g.customer_name,                                                                                                                                                                                                                                                                                                                     +
+     g.product_name,                                                                                                                                                                                                                                                                                                                          +
+     g.price,                                                                                                                                                                                                                                                                                                                                 +
+     g.a                                                                                                                                                                                                                                                                                                                                      +
+    FROM x1,                                                                                                                                                                                                                                                                                                                                  +
+     GRAPH_TABLE (myshop MATCH (c IS customers WHERE (((c.address)::text = 'US'::text) AND (c.customer_id = x1.a)))-[IS customer_orders|customer_wishlists]->(l IS orders|wishlists)-[IS list_items]->(p IS products) WHERE (p.price > (0)::numeric) COLUMNS (c.name AS customer_name, p.name AS product_name, p.price AS price, x1.a AS a)) g+
    ORDER BY g.customer_name, g.product_name;
 (1 row)
 

diff --git a/src/test/regress/sql/graph_table.sql b/src/test/regress/sql/graph_table.sql
index 3fb0e50ddb29dbb9f215c8e8eb90094a68bc7501..85298f93964a2995189bc41dad3125198b3efd27 100644 (file)
--- a/src/test/regress/sql/graph_table.sql
+++ b/src/test/regress/sql/graph_table.sql
@@ -539,13 +539,14 @@ SELECT * FROM GRAPH_TABLE (g4 MATCH (s WHERE s.id = 3)-[e]-(d) COLUMNS (s.val, e
 -- GRAPH_TABLE in views
 
 -- The query in the view definition is intentionally complex to test one view with many
--- features like label disjunction, lateral references, WHERE clauses in graph
--- patterns.
+-- features like label disjunction, lateral references, WHERE clauses on graph
+-- pattern elements as well as on the whole graph pattern.
 CREATE VIEW customers_us AS
 SELECT g.* FROM x1,
                 GRAPH_TABLE (myshop MATCH (c IS customers WHERE c.address = 'US' AND c.customer_id = x1.a)
                                           -[IS customer_orders | customer_wishlists ]->
                                           (l IS orders | wishlists)-[ IS list_items]->(p IS products)
+                                    WHERE p.price > 0
                                     COLUMNS (c.name AS customer_name, p.name AS product_name, p.price, x1.a AS a)) g
            ORDER BY customer_name, product_name;
 -- Dropping properties or labels used by a view is not allowed