PS-9390 fix: JSON_TABLE and EXISTS() does not work

https://perconadev.atlassian.net/browse/PS-9390

Backported the fix for Bug #114897 / #36606073
(https://bugs.mysql.com/bug.php?id=114897)
"json_table and exists make a bug"
(commit 15e6812@mysql/mysql-server)
which was added by Oracle in 9.3.0 but not in 8.4.5 / 8.0.42.

In addition, 'json.json_table' MTR test case extended with the
original query reported in PS-9390.

Author: kahatlen

mysql-test/suite/json/r/json_table.result

@@ -2196,3 +2196,29 @@ SELECT * FROM JSON_TABLE('[1, 2]', '$' COLUMNS (
 #
 SELECT 1 FROM JSON_TABLE(ROW(1, 2), '$' COLUMNS (o FOR ORDINALITY)) AS jt;
 ERROR 21000: Operand should contain 1 column(s)
+#
+# Bug#36606073: json_table and exists make a bug
+#
+CREATE TABLE t(x VARCHAR(10));
+INSERT INTO t VALUES ('[1]'), ('[2]'), ('[3]');
+SELECT * FROM t WHERE EXISTS (
+SELECT * FROM JSON_TABLE(x, '$[*]' COLUMNS (i INT PATH '$')) AS jt WHERE i = 2
+);
+x
+[2]
+DROP TABLE t;
+#
+# PS-9390: JSON_TABLE and EXISTS() does not work
+# https://perconadev.atlassian.net/browse/PS-9390
+#
+CREATE TABLE t (id INT PRIMARY KEY, b JSON);
+INSERT INTO t SET id = 1, b = '{"a": [{"b": "1"}]}';
+SELECT * FROM t WHERE EXISTS(SELECT 1 FROM JSON_TABLE(t.b, '$."a"[*]' COLUMNS (col1 VARCHAR(100) PATH '$.b' )) a);
+id	b
+1	{"a": [{"b": "1"}]}
+INSERT INTO t SET id = 2, b = '{"a": [{"b": "2"}]}';
+SELECT * FROM t WHERE EXISTS(SELECT 1 FROM JSON_TABLE(t.b, '$."a"[*]' COLUMNS (col1 VARCHAR(100) PATH '$.b' )) a);
+id	b
+1	{"a": [{"b": "1"}]}
+2	{"a": [{"b": "2"}]}
+DROP TABLE t;

mysql-test/suite/json/t/json_table.test

@@ -1533,3 +1533,26 @@ SELECT * FROM JSON_TABLE('[1, 2]', '$' COLUMNS (
 --echo #
 --error ER_OPERAND_COLUMNS
 SELECT 1 FROM JSON_TABLE(ROW(1, 2), '$' COLUMNS (o FOR ORDINALITY)) AS jt;
+
+--echo #
+--echo # Bug#36606073: json_table and exists make a bug
+--echo #
+
+CREATE TABLE t(x VARCHAR(10));
+INSERT INTO t VALUES ('[1]'), ('[2]'), ('[3]');
+SELECT * FROM t WHERE EXISTS (
+  SELECT * FROM JSON_TABLE(x, '$[*]' COLUMNS (i INT PATH '$')) AS jt WHERE i = 2
+);
+DROP TABLE t;
+
+--echo #
+--echo # PS-9390: JSON_TABLE and EXISTS() does not work
+--echo # https://perconadev.atlassian.net/browse/PS-9390
+--echo #
+
+CREATE TABLE t (id INT PRIMARY KEY, b JSON);
+INSERT INTO t SET id = 1, b = '{"a": [{"b": "1"}]}';
+SELECT * FROM t WHERE EXISTS(SELECT 1 FROM JSON_TABLE(t.b, '$."a"[*]' COLUMNS (col1 VARCHAR(100) PATH '$.b' )) a);
+INSERT INTO t SET id = 2, b = '{"a": [{"b": "2"}]}';
+SELECT * FROM t WHERE EXISTS(SELECT 1 FROM JSON_TABLE(t.b, '$."a"[*]' COLUMNS (col1 VARCHAR(100) PATH '$.b' )) a);
+DROP TABLE t;

sql/sql_resolver.cc

@@ -107,6 +107,7 @@
 #include "sql/sql_union.h"  // Query_result_union
 #include "sql/system_variables.h"
 #include "sql/table.h"
+#include "sql/table_function.h"
 #include "sql/thd_raii.h"
 #include "sql/thr_malloc.h"
 #include "sql/visible_fields.h"
@@ -2354,6 +2355,11 @@ static void fix_tables_after_pullout(Query_block *parent_query_block,
       "lateral CTE".
     */
   }
+
+  if (tr->is_table_function()) {
+    tr->table_function->fix_after_pullout(parent_query_block,
+                                          removed_query_block);
+  }
 }
 
 /**

sql/table_function.cc

@@ -93,6 +93,12 @@ bool Table_function::init_args() {
   return false;
 }
 
+void Table_function::fix_after_pullout(Query_block *parent_query_block,
+                                       Query_block *removed_query_block) {
+  do_fix_after_pullout(parent_query_block, removed_query_block);
+  table->pos_in_table_list->dep_tables = used_tables();
+}
+
 /******************************************************************************
   Implementation of JSON_TABLE function
 ******************************************************************************/
@@ -766,6 +772,11 @@ void Table_function_json::do_cleanup() {
   for (uint i = 0; i < m_all_columns.size(); i++) m_all_columns[i]->cleanup();
 }
 
+void Table_function_json::do_fix_after_pullout(
+    Query_block *parent_query_block, Query_block *removed_query_block) {
+  source->fix_after_pullout(parent_query_block, removed_query_block);
+}
+
 void JT_data_source::cleanup() {
   v.clear();
   producing_records = false;
@@ -870,6 +881,11 @@ void Table_function_sequence::do_cleanup() {
   m_precalculated_upper_bound = 0;
 }
 
+void Table_function_sequence::do_fix_after_pullout(
+    Query_block *parent_query_block, Query_block *removed_query_block) {
+  m_source->fix_after_pullout(parent_query_block, removed_query_block);
+}
+
 ulonglong Table_function_sequence::calculate_upper_bound() const {
   ulonglong res = 0;
   if (!m_source->is_null()) {

sql/table_function.h

@@ -158,6 +158,17 @@ class Table_function {
 
   virtual bool walk(Item_processor processor, enum_walk walk, uchar *arg) = 0;
 
+  /**
+    Fix after tables have been moved from one query_block level to the parent
+    level, e.g by semijoin conversion.
+
+    @param parent_query_block  query_block that tables are moved to.
+    @param removed_query_block query_block that tables are moved away from,
+                          child of parent_query_block.
+  */
+  void fix_after_pullout(Query_block *parent_query_block,
+                         Query_block *removed_query_block);
+
  private:
   /**
     Get the list of fields to create the result table
@@ -173,6 +184,8 @@ class Table_function {
   virtual bool do_init_args() = 0;
   friend bool Table_ref::setup_table_function(THD *thd);
   virtual void do_cleanup() {}
+  virtual void do_fix_after_pullout(Query_block *parent_query_block,
+                                    Query_block *removed_query_block) = 0;
 };
 
 /****************************************************************************
@@ -431,6 +444,8 @@ class Table_function_json final : public Table_function {
   List<Create_field> *get_field_list() override;
   bool do_init_args() override;
   void do_cleanup() override;
+  void do_fix_after_pullout(Query_block *parent_query_block,
+                            Query_block *removed_query_block) override;
 };
 
 class Table_function_sequence final : public Table_function {
@@ -501,6 +516,8 @@ class Table_function_sequence final : public Table_function {
   virtual List<Create_field> *get_field_list() override;
   virtual bool do_init_args() override;
   virtual void do_cleanup() override;
+  void do_fix_after_pullout(Query_block *parent_query_block,
+                            Query_block *removed_query_block) override;
 
   ulonglong calculate_upper_bound() const;
 };