1berry/MariaDB-server
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

MDEV-25202: JSON_TABLE: Early table reference leads to unexpected result set

Browse Source 
Address review input: switch Name_resolution_context::ignored_tables from
table_map to a list of TABLE_LIST objects. The rationale is that table
bits may be changed due to query rewrites, etc, which may potentially
require updating ignored_tables.
This commit is contained in:
Sergei Petrunia 2021-04-16 19:50:08 +03:00 committed by Alexey Botchkov
parent 0984b8ed08
commit b0817ff8de
8 changed files with 150 additions and 64 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

17
mysql-test/suite/json/r/json_table.result
View File

@ -790,6 +790,23 @@ ON t1.a = tt.b;
a b c o
1 1 {} 1
2 2 [] NULL
prepare s from
"SELECT *
FROM
t1 RIGHT JOIN
v2 AS tt
LEFT JOIN
JSON_TABLE(CONCAT(tt.c,''), '$' COLUMNS(o FOR ORDINALITY)) AS jt
ON tt.b = jt.o
ON t1.a = tt.b";
execute s;
a b c o
1 1 {} 1
2 2 [] NULL
execute s;
a b c o
1 1 {} 1
2 2 [] NULL
DROP VIEW v2;
DROP TABLE t1, t2;
#

13
mysql-test/suite/json/t/json_table.test
View File

@ -682,6 +682,19 @@ FROM
ON tt.b = jt.o
ON t1.a = tt.b;
prepare s from
"SELECT *
FROM
t1 RIGHT JOIN
v2 AS tt
LEFT JOIN
JSON_TABLE(CONCAT(tt.c,''), '$' COLUMNS(o FOR ORDINALITY)) AS jt
ON tt.b = jt.o
ON t1.a = tt.b";
execute s;
execute s;
DROP VIEW v2;
DROP TABLE t1, t2;

15
sql/item.cc
View File

@ -10713,3 +10713,18 @@ bool Item::cleanup_excluding_immutables_processor (void *arg)
return false;
}
}
bool ignored_list_includes_table(ignored_tables_list_t list, TABLE_LIST *tbl)
{
if (!list)
return false;
List_iterator<TABLE_LIST> it(*list);
TABLE_LIST *list_tbl;
while ((list_tbl = it++))
{
if (list_tbl == tbl)
return true;
}
return false;
}

7
sql/item.h
View File

@ -162,6 +162,9 @@ void dummy_error_processor(THD *thd, void *data);
void view_error_processor(THD *thd, void *data);
typedef List<TABLE_LIST>* ignored_tables_list_t;
bool ignored_list_includes_table(ignored_tables_list_t list, TABLE_LIST *tbl);
/*
Instances of Name_resolution_context store the information necessary for
name resolution of Items and other context analysis of a query made in
@ -236,7 +239,7 @@ struct Name_resolution_context: Sql_alloc
Bitmap of tables that should be ignored when doing name resolution.
Normally it is {0}. Non-zero values are used by table functions.
*/
table_map ignored_tables;
ignored_tables_list_t ignored_tables;
/*
Security context of this name resolution context. It's used for views
@ -247,7 +250,7 @@ struct Name_resolution_context: Sql_alloc
Name_resolution_context()
:outer_context(0), table_list(0), select_lex(0),
error_processor_data(0),
ignored_tables(0),
ignored_tables(NULL),
security_ctx(0)
{}

109
sql/json_table.cc
View File

@ -44,9 +44,14 @@ static table_function_handlerton table_function_hton;
/*
@brief
Collect a bitmap of tables that a given table function cannot have
Collect a set of tables that a given table function cannot have
references to.
@param
table_func The table function we are connecting info for
join_list The nested join to be processed
disallowed_tables Collect the tables here.
@detail
According to the SQL standard, a table function can refer to any table
that's "preceding" it in the FROM clause.
@ -80,16 +85,16 @@ static table_function_handlerton table_function_hton;
we are ok with operating on the tables "in the left join order".
@return
TRUE - enumeration has found the Table Function instance. The bitmap is
ready.
FALSE - Otherwise
0 - Continue
1 - Finish the process, success
-1 - Finish the process, failure
*/
static
bool get_disallowed_table_deps_for_list(table_map table_func_bit,
int get_disallowed_table_deps_for_list(MEM_ROOT *mem_root,
TABLE_LIST *table_func,
List<TABLE_LIST> *join_list,
table_map *disallowed_tables)
List<TABLE_LIST> *disallowed_tables)
{
TABLE_LIST *table;
NESTED_JOIN *nested_join;
@ -99,23 +104,25 @@ bool get_disallowed_table_deps_for_list(table_map table_func_bit,
{
if ((nested_join= table->nested_join))
{
if (get_disallowed_table_deps_for_list(table_func_bit,
int res;
if ((res= get_disallowed_table_deps_for_list(mem_root, table_func,
&nested_join->join_list,
disallowed_tables))
return true;
disallowed_tables)))
return res;
}
else
{
*disallowed_tables |= table->table->map;
if (table_func_bit == table->table->map)
if (disallowed_tables->push_back(table, mem_root))
return -1;
if (table == table_func)
{
// This is the JSON_TABLE(...) that are we're computing dependencies
// for.
return true;
return 1; // Finish the processing
}
}
}
return false;
return 0; // Continue
}
@ -129,19 +136,31 @@ bool get_disallowed_table_deps_for_list(table_map table_func_bit,
See get_disallowed_table_deps_for_list
@return
Bitmap of tables that table function can NOT have references to.
NULL - Out of memory
Other - A list of tables that the function cannot have references to. May
be empty.
*/
static
table_map get_disallowed_table_deps(JOIN *join, table_map table_func_bit)
List<TABLE_LIST>* get_disallowed_table_deps(MEM_ROOT *mem_root,
SELECT_LEX *select,
TABLE_LIST *table_func)
{
table_map disallowed_tables= 0;
if (!get_disallowed_table_deps_for_list(table_func_bit, join->join_list,
&disallowed_tables))
{
// We haven't found the table with table_func_bit in all tables?
DBUG_ASSERT(0);
}
List<TABLE_LIST> *disallowed_tables;
if (!(disallowed_tables = new List<TABLE_LIST>))
return NULL;
int res= get_disallowed_table_deps_for_list(mem_root, table_func,
select->join_list,
disallowed_tables);
// The collection process must have finished
DBUG_ASSERT(res != 0);
if (res == -1)
return NULL; // Out of memory
return disallowed_tables;
}
@ -1034,48 +1053,56 @@ bool push_table_function_arg_context(LEX *lex, MEM_ROOT *alloc)
Perform name-resolution phase tasks
@detail
- The only argument that needs resolution is the JSON text
- Then, we need to set dependencies: if JSON_TABLE refers to table's
column, e.g.
The only argument that needs name resolution is the first parameter which
has the JSON text:
JSON_TABLE (t1.col ... ) AS t2
JSON_TABLE(json_doc, ... )
then it can be computed only after table t1.
- The dependencies must not form a loop.
The argument may refer to other tables and uses special name resolution
rules (see get_disallowed_table_deps_for_list for details). This function
sets up Name_resolution_context object appropriately before calling
fix_fields for the argument.
@return
false OK
true Fatal error
*/
int Table_function_json_table::setup(THD *thd, TABLE_LIST *sql_table,
bool Table_function_json_table::setup(THD *thd, TABLE_LIST *sql_table,
SELECT_LEX *s_lex)
{
TABLE *t= sql_table->table;
thd->where= "JSON_TABLE argument";
{
bool save_is_item_list_lookup;
bool res;
save_is_item_list_lookup= s_lex->is_item_list_lookup;
s_lex->is_item_list_lookup= 0;
if (!m_context_setup_done)
{
m_context_setup_done= true;
// Prepare the name resolution context. First, copy the context that is
// used for name resolution of the WHERE clause
*m_context= s_lex->context;
// Then, restrict it to only allow to refer to tables that come before the
// table function reference
m_context->ignored_tables= get_disallowed_table_deps(s_lex->join, t->map);
if (!(m_context->ignored_tables=
get_disallowed_table_deps(thd->stmt_arena->mem_root, s_lex,
sql_table)))
return TRUE; // Error
}
bool save_is_item_list_lookup;
save_is_item_list_lookup= s_lex->is_item_list_lookup;
s_lex->is_item_list_lookup= 0;
// Do the same what setup_without_group() does: do not count the referred
// fields in non_agg_field_used:
const bool saved_non_agg_field_used= s_lex->non_agg_field_used();
res= m_json->fix_fields_if_needed(thd, &m_json);
bool res= m_json->fix_fields_if_needed(thd, &m_json);
s_lex->is_item_list_lookup= save_is_item_list_lookup;
s_lex->set_non_agg_field_used(saved_non_agg_field_used);
if (res)
return TRUE;
}
return TRUE; // Error
return FALSE;
}

7
sql/json_table.h
View File

@ -198,7 +198,7 @@ public:
List<Json_table_column> m_columns;
/*** Name resolution functions ***/
int setup(THD *thd, TABLE_LIST *sql_table, SELECT_LEX *s_lex);
bool setup(THD *thd, TABLE_LIST *sql_table, SELECT_LEX *s_lex);
int walk_items(Item_processor processor, bool walk_subquery,
void *argument);
@ -226,7 +226,8 @@ public:
/*** Construction interface to be used from the parser ***/
Table_function_json_table(Item *json):
m_json(json)
m_json(json),
m_context_setup_done(false)
{
cur_parent= &m_nested_path;
last_sibling_hook= &m_nested_path.m_nested;
@ -250,6 +251,8 @@ private:
/* Context to be used for resolving the first argument. */
Name_resolution_context *m_context;
bool m_context_setup_done;
/* Current NESTED PATH level being parsed */
Json_table_nested_path *cur_parent;

19
sql/sql_base.cc
View File

@ -6101,7 +6101,8 @@ Field *
find_field_in_table_ref(THD *thd, TABLE_LIST *table_list,
const char *name, size_t length,
const char *item_name, const char *db_name,
const char *table_name, table_map ignored_tables,
const char *table_name,
ignored_tables_list_t ignored_tables,
Item **ref,
bool check_privileges, bool allow_rowid,
uint *cached_field_index_ptr,
@ -6194,8 +6195,13 @@ find_field_in_table_ref(THD *thd, TABLE_LIST *table_list,
TABLE_LIST *table;
while ((table= it++))
{
if (table->table && (table->table->map & ignored_tables))
/*
Check if the table is in the ignore list. Only base tables can be in
the ignore list.
*/
if (table->table && ignored_list_includes_table(ignored_tables, table))
continue;
if ((fld= find_field_in_table_ref(thd, table, name, length, item_name,
db_name, table_name, ignored_tables,
ref, check_privileges, allow_rowid,
@ -6322,8 +6328,8 @@ Field *find_field_in_table_sef(TABLE *table, const char *name)
first_table list of tables to be searched for item
last_table end of the list of tables to search for item. If NULL
then search to the end of the list 'first_table'.
ignored_tables Bitmap of tables that should be ignored. Do not try
to find the field in those.
ignored_tables Set of tables that should be ignored. Do not try to
find the field in those.
ref if 'item' is resolved to a view field, ref is set to
point to the found view field
report_error Degree of error reporting:
@ -6351,7 +6357,7 @@ Field *find_field_in_table_sef(TABLE *table, const char *name)
Field *
find_field_in_tables(THD *thd, Item_ident *item,
TABLE_LIST *first_table, TABLE_LIST *last_table,
table_map ignored_tables,
ignored_tables_list_t ignored_tables,
Item **ref, find_item_error_report_type report_error,
bool check_privileges, bool register_tree_change)
{
@ -6475,7 +6481,8 @@ find_field_in_tables(THD *thd, Item_ident *item,
for (; cur_table != last_table ;
cur_table= cur_table->next_name_resolution_table)
{
if (cur_table->table && (cur_table->table->map & ignored_tables))
if (cur_table->table &&
ignored_list_includes_table(ignored_tables, cur_table))
continue;
Field *cur_field= find_field_in_table_ref(thd, cur_table, name, length,

5
sql/sql_base.h
View File

@ -195,14 +195,15 @@ bool fill_record(THD *thd, TABLE *table, Field **field, List<Item> &values,
Field *
find_field_in_tables(THD *thd, Item_ident *item,
TABLE_LIST *first_table, TABLE_LIST *last_table,
table_map ignored_tables,
ignored_tables_list_t ignored_tables,
Item **ref, find_item_error_report_type report_error,
bool check_privileges, bool register_tree_change);
Field *
find_field_in_table_ref(THD *thd, TABLE_LIST *table_list,
const char *name, size_t length,
const char *item_name, const char *db_name,
const char *table_name, table_map ignored_tables,
const char *table_name,
ignored_tables_list_t ignored_tables,
Item **ref, bool check_privileges, bool allow_rowid,
uint *cached_field_index_ptr,
bool register_tree_change, TABLE_LIST **actual_table);