diff options
Diffstat (limited to 'sql/sql_select.cc')
| -rw-r--r-- | sql/sql_select.cc | 48 |
1 files changed, 32 insertions, 16 deletions
diff --git a/sql/sql_select.cc b/sql/sql_select.cc index 939ec003aca..04368c016d1 100644 --- a/sql/sql_select.cc +++ b/sql/sql_select.cc @@ -153,7 +153,7 @@ mysql_select(THD *thd,TABLE_LIST *tables,List<Item> &fields,COND *conds, uint select_options,select_result *result) { TABLE *tmp_table; - int error,tmp; + int error, tmp_error; bool need_tmp,hidden_group_fields; bool simple_order,simple_group,no_order; Item::cond_result cond_value; @@ -380,9 +380,9 @@ mysql_select(THD *thd,TABLE_LIST *tables,List<Item> &fields,COND *conds, thd->fatal_error) goto err; thd->proc_info="preparing"; - if ((tmp=join_read_const_tables(&join)) > 0) + if ((tmp_error=join_read_const_tables(&join)) > 0) goto err; - if (tmp && !(select_options & SELECT_DESCRIBE)) + if (tmp_error && !(select_options & SELECT_DESCRIBE)) { error=return_zero_rows(result,tables,fields, join.tmp_table_param.sum_func_count != 0 && @@ -701,9 +701,11 @@ mysql_select(THD *thd,TABLE_LIST *tables,List<Item> &fields,COND *conds, group=0; } thd->proc_info="Copying to group table"; + tmp_error= -1; if (make_sum_func_list(&join,all_fields) || - do_select(&join,(List<Item> *) 0,tmp_table2,0)) + (tmp_error=do_select(&join,(List<Item> *) 0,tmp_table2,0))) { + error=tmp_error; free_tmp_table(thd,tmp_table2); goto err; /* purecov: inspected */ } @@ -3347,7 +3349,11 @@ create_tmp_table(THD *thd,TMP_TABLE_PARAM *param,List<Item> &fields, if (!param->quick_group) group=0; // Can't use group key else for (ORDER *tmp=group ; tmp ; tmp=tmp->next) + { (*tmp->item)->marker=4; // Store null in key + if ((*tmp->item)->max_length >= MAX_CHAR_WIDTH) + using_unique_constraint=1; + } if (param->group_length >= MAX_BLOB_WIDTH) using_unique_constraint=1; if (group) @@ -3477,7 +3483,7 @@ create_tmp_table(THD *thd,TMP_TABLE_PARAM *param,List<Item> &fields, field_count= (uint) (reg_field - table->field); /* If result table is small; use a heap */ - if (blob_count || using_unique_constraint || + if (blob_count || using_unique_constraint || group_null_items || (select_options & (OPTION_BIG_TABLES | SELECT_SMALL_RESULT)) == OPTION_BIG_TABLES) { @@ -3499,7 +3505,7 @@ create_tmp_table(THD *thd,TMP_TABLE_PARAM *param,List<Item> &fields, if (blob_count == 0) { /* We need to ensure that first byte is not 0 for the delete link */ - if (hidden_null_count) + if (param->hidden_field_count) hidden_null_count++; else null_count++; @@ -3633,14 +3639,17 @@ create_tmp_table(THD *thd,TMP_TABLE_PARAM *param,List<Item> &fields, if (maybe_null) { /* - To be able to group on NULL, we move the null bit to be - just before the column and extend the key to cover the null bit + To be able to group on NULL, we reserve place in group_buff + for the NULL flag just before the column. + The field data is after this flag. + The NULL flag is updated by 'end_update()' and 'end_write()' */ - *group_buff= 0; // Init null byte - key_part_info->offset--; - key_part_info->length++; - group->field->move_field((char*) group_buff+1, (uchar*) group_buff, - 1); + keyinfo->flags|= HA_NULL_ARE_EQUAL; // def. that NULL == NULL + key_part_info->null_bit=field->null_bit; + key_part_info->null_offset= (uint) (field->null_ptr - + (uchar*) table->record[0]); + group->field->move_field((char*) ++group->buff); + group_buff++; } else group->field->move_field((char*) group_buff); @@ -3820,11 +3829,17 @@ static bool create_myisam_tmp_table(TABLE *table,TMP_TABLE_PARAM *param, keyinfo->key_part[i].length > 4) seg->flag|=HA_SPACE_PACK; } - if (using_unique_constraint && - !(field->flags & NOT_NULL_FLAG)) + if (!(field->flags & NOT_NULL_FLAG)) { seg->null_bit= field->null_bit; seg->null_pos= (uint) (field->null_ptr - (uchar*) table->record[0]); + /* + We are using a GROUP BY on something that contains NULL + In this case we have to tell MyISAM that two NULL should + on INSERT be compared as equal + */ + if (!using_unique_constraint) + keydef.flag|= HA_NULL_ARE_EQUAL; } } } @@ -4797,8 +4812,9 @@ end_update(JOIN *join, JOIN_TAB *join_tab __attribute__((unused)), { Item *item= *group->item; item->save_org_in_field(group->field); + /* Store in the used key if the field was 0 */ if (item->maybe_null) - group->buff[0]=item->null_value ? 0: 1; // Save reversed value + group->buff[-1]=item->null_value ? 1 : 0; } // table->file->index_init(0); if (!table->file->index_read(table->record[1], |