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MDEV-34123 CONCAT Function Returns Unexpected Empty Set in Query

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Search conditions were evaluated using val_int(), which was wrong.
Fixing the code to use val_bool() instead.

Details:
- Adding a new item_base_t::IS_COND flag which marks Items used
  as <search condition> in WHERE, HAVING, JOIN ON, CASE WHEN clauses.
  The flag is at the parse time.
  These expressions must be evaluated using val_bool() rather than val_int().

  Note, the optimizer creates more Items which are used as search conditions.
  Most of these items are not marked with IS_COND yet. This is OK for now,
  but eventually these Items can also be fixed to have the flag.

- Adding a method Item::is_cond() which tests if the Item has the IS_COND flag.

- Implementing Item_cache_bool. It evaluates the cached expression using
  val_bool() rather than val_int().
  Overriding Type_handler_bool::Item_get_cache() to create Item_cache_bool.

- Implementing Item::save_bool_in_field(). It uses val_bool() rather than
  val_int() to evaluate the expression.

- Implementing Type_handler_bool::Item_save_in_field()
  using Item::save_bool_in_field().

- Fixing all Item_bool_func descendants to implement a virtual val_bool()
  rather than a virtual val_int().

- To find places where val_int() should be fixed to val_bool(), a few
  DBUG_ASSERT(!is_cond()) where added into val_int() implementations
  of selected (most frequent) classes:

  Item_field
  Item_str_func
  Item_datefunc
  Item_timefunc
  Item_datetimefunc
  Item_cache_bool
  Item_bool_func
  Item_func_hybrid_field_type
  Item_basic_constant descendants

- Fixing all places where DBUG_ASSERT() happened during an "mtr" run
  to use val_bool() instead of val_int().
This commit is contained in:
Alexander Barkov
2024-05-14 09:19:34 +04:00
committed by Oleksandr Byelkin
parent 6f6c1911dc
commit a931da82fa
52 changed files with 2098 additions and 151 deletions
Download Patch File Download Diff File Expand all files Collapse all files

37
sql/sql_select.cc
View File

@@ -3212,7 +3212,7 @@ int JOIN::optimize_stage2()
having->update_used_tables();
if (having->const_item() && !having->is_expensive())
{
if (!having->val_int())
if (!having->val_bool())
{
having= const_cast<Item_bool_static*>(&Item_false);
zero_result_cause= "Impossible HAVING noticed after reading const tables";
@@ -4791,8 +4791,8 @@ void JOIN::exec_inner()
DBUG_ASSERT(error == 0);
if (cond_value != Item::COND_FALSE &&
having_value != Item::COND_FALSE &&
(!conds || conds->val_int()) &&
(!having || having->val_int()))
(!conds || conds->val_bool()) &&
(!having || having->val_bool()))
{
if (do_send_rows &&
(procedure ? (procedure->send_row(procedure_fields_list) ||
@@ -4825,11 +4825,11 @@ void JOIN::exec_inner()
*/
if (!zero_result_cause &&
exec_const_cond && !(select_options & SELECT_DESCRIBE) &&
!exec_const_cond->val_int())
!exec_const_cond->val_bool())
zero_result_cause= "Impossible WHERE noticed after reading const tables";
/*
We've called exec_const_cond->val_int(). This may have caused an error.
We've called exec_const_cond->val_bool(). This may have caused an error.
*/
if (unlikely(thd->is_error()))
{
@@ -12846,7 +12846,7 @@ make_join_select(JOIN *join,SQL_SELECT *select,COND *cond)
bool const_cond_result;
{
Json_writer_array a(thd, "computing_condition");
const_cond_result= const_cond->val_int() != 0;
const_cond_result= const_cond->val_bool() != 0;
}
if (!const_cond_result)
{
@@ -15992,7 +15992,7 @@ return_zero_rows(JOIN *join, select_result *result, List<TABLE_LIST> *tables,
join->no_rows_in_result_called= 1;
while ((item= it++))
item->no_rows_in_result();
if (having && having->val_int() == 0)
if (having && having->val_bool() == false)
send_row=0;
}
@@ -17338,6 +17338,7 @@ Item *eliminate_item_equal(THD *thd, COND *cond, COND_EQUAL *upper_levels,
return 0;
eq_item->eval_not_null_tables(0);
eq_item->quick_fix_field();
eq_item->base_flags|= item_base_t::IS_COND;
}
current_sjm= field_sjm;
}
@@ -21780,7 +21781,7 @@ do_select(JOIN *join, Procedure *procedure)
sufficient to check only the condition pseudo_bits_cond.
*/
DBUG_ASSERT(join->outer_ref_cond == NULL);
if (!join->pseudo_bits_cond || join->pseudo_bits_cond->val_int())
if (!join->pseudo_bits_cond || join->pseudo_bits_cond->val_bool())
{
// HAVING will be checked by end_select
error= (*end_select)(join, 0, 0);
@@ -21841,7 +21842,7 @@ do_select(JOIN *join, Procedure *procedure)
JOIN_TAB *join_tab= join->join_tab +
(join->tables_list ? join->const_tables : 0);
if (join->outer_ref_cond && !join->outer_ref_cond->val_int())
if (join->outer_ref_cond && !join->outer_ref_cond->val_bool())
error= NESTED_LOOP_NO_MORE_ROWS;
else
error= join->first_select(join,join_tab,0);
@@ -22419,7 +22420,7 @@ evaluate_join_record(JOIN *join, JOIN_TAB *join_tab,
if (select_cond)
{
select_cond_result= MY_TEST(select_cond->val_int());
select_cond_result= MY_TEST(select_cond->val_bool());
/* check for errors evaluating the condition */
if (unlikely(join->thd->is_error()))
@@ -22815,7 +22816,7 @@ join_read_const_table(THD *thd, JOIN_TAB *tab, POSITION *pos)
(*tab->on_expr_ref)->update_used_tables();
DBUG_ASSERT((*tab->on_expr_ref)->const_item());
#endif
if ((table->null_row= MY_TEST((*tab->on_expr_ref)->val_int() == 0)))
if ((table->null_row= MY_TEST((*tab->on_expr_ref)->val_bool() == 0)))
mark_as_null_row(table);
}
if (!table->null_row && ! tab->join->mixed_implicit_grouping)
@@ -23571,7 +23572,7 @@ end_send(JOIN *join, JOIN_TAB *join_tab, bool end_of_records)
/* Copy non-aggregated fields when loose index scan is used. */
copy_fields(&join->tmp_table_param);
}
if (join->having && join->having->val_int() == 0)
if (join->having && join->having->val_bool() == 0)
DBUG_RETURN(NESTED_LOOP_OK); // Didn't match having
if (join->procedure)
{
@@ -23762,7 +23763,7 @@ end_send_group(JOIN *join, JOIN_TAB *join_tab, bool end_of_records)
while ((item= it++))
item->no_rows_in_result();
}
if (join->having && join->having->val_int() == 0)
if (join->having && join->having->val_bool() == 0)// TODO: tests
error= -1; // Didn't satisfy having
else
{
@@ -23872,7 +23873,7 @@ end_write(JOIN *join, JOIN_TAB *join_tab __attribute__((unused)),
if (copy_funcs(join_tab->tmp_table_param->items_to_copy, join->thd))
DBUG_RETURN(NESTED_LOOP_ERROR); /* purecov: inspected */
if (likely(!join_tab->having || join_tab->having->val_int()))
if (likely(!join_tab->having || join_tab->having->val_bool()))
{
int error;
join->found_records++;
@@ -24123,7 +24124,7 @@ end_write_group(JOIN *join, JOIN_TAB *join_tab __attribute__((unused)),
}
copy_sum_funcs(join->sum_funcs,
join->sum_funcs_end[send_group_parts]);
if (!join_tab->having || join_tab->having->val_int())
if (!join_tab->having || join_tab->having->val_bool())
{
int error= table->file->ha_write_tmp_row(table->record[0]);
if (unlikely(error) &&
@@ -26126,7 +26127,7 @@ static int remove_dup_with_compare(THD *thd, TABLE *table, Field **first_field,
break;
goto err;
}
if (having && !having->val_int())
if (having && !having->val_bool())
{
if (unlikely((error= file->ha_delete_row(record))))
goto err;
@@ -26264,7 +26265,7 @@ static int remove_dup_with_hash_index(THD *thd, TABLE *table,
break;
goto err;
}
if (having && !having->val_int())
if (having && !having->val_bool())
{
if (unlikely((error= file->ha_delete_row(record))))
goto err;
@@ -28401,7 +28402,7 @@ int JOIN::rollup_send_data(uint idx)
int res= 0;
/* Get reference pointers to sum functions in place */
copy_ref_ptr_array(ref_ptrs, rollup.ref_pointer_arrays[i]);
if ((!having || having->val_int()))
if ((!having || having->val_bool()))
{
if (send_records < unit->lim.get_select_limit() && do_send_rows &&
(res= result->send_data_with_check(rollup.fields[i],