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subqueries made printable

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new EXPLAIN parameter to show real query as it was interpreted
(SCRUM) (WL#1274)
This commit is contained in:
bell@sanja.is.com.ua
2003-10-16 15:54:47 +03:00
parent ddf4d1e529
commit a7bdd19707
18 changed files with 735 additions and 181 deletions
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184
sql/sql_select.cc
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@ -328,6 +328,20 @@ JOIN::prepare(Item ***rref_pointer_array,
having->split_sum_func(ref_pointer_array, all_fields);
}
#ifndef DEBUG_OFF
{
char buff[256];
String str(buff,(uint32) sizeof(buff), system_charset_info);
str.length(0);
if (select_lex->master_unit()->item)
select_lex->master_unit()->item->print(&str);
else
unit->print(&str);
str.append('\0');
DBUG_PRINT("info", ("(SUB)SELECT: %s", str.ptr()));
}
#endif
// Is it subselect
{
Item_subselect *subselect;
@ -880,12 +894,12 @@ JOIN::optimize()
need_tmp=1; simple_order=simple_group=0; // Force tmp table without sort
}
tmp_having= having;
if (select_options & SELECT_DESCRIBE)
{
error= 0;
DBUG_RETURN(0);
}
tmp_having= having;
having= 0;
/* Perform FULLTEXT search before all regular searches */
@ -1547,11 +1561,23 @@ mysql_select(THD *thd, Item ***rref_pointer_array,
goto err; // 1
}
if (thd->lex.describe & DESCRIBE_EXTENDED)
{
join->conds_history= join->conds;
join->having_history= (join->having?join->having:join->tmp_having);
}
if (thd->net.report_error)
goto err;
join->exec();
if (thd->lex.describe & DESCRIBE_EXTENDED)
{
select_lex->where= join->conds_history;
select_lex->having= join->having_history;
}
err:
if (free_join)
{
@ -8909,3 +8935,159 @@ int mysql_explain_select(THD *thd, SELECT_LEX *select_lex, char const *type,
result, unit, select_lex, 0);
DBUG_RETURN(res);
}
void st_select_lex::print(THD *thd, String *str)
{
if (!thd)
thd= current_thd;
str->append("select ");
//options
if (options & SELECT_STRAIGHT_JOIN)
str->append("straight_join ");
if ((thd->lex.lock_option & TL_READ_HIGH_PRIORITY) &&
(this == &thd->lex.select_lex))
str->append("high_priority ");
if (options & SELECT_DISTINCT)
str->append("distinct ");
if (options & SELECT_SMALL_RESULT)
str->append("small_result ");
if (options & SELECT_BIG_RESULT)
str->append("big_result ");
if (options & OPTION_BUFFER_RESULT)
str->append("buffer_result ");
if (options & OPTION_FOUND_ROWS)
str->append("calc_found_rows ");
if (!thd->lex.safe_to_cache_query)
str->append("no_cache ");
if (options & OPTION_TO_QUERY_CACHE)
str->append("cache ");
//Item List
bool first= 1;
List_iterator_fast<Item> it(item_list);
Item *item;
while ((item= it++))
{
if (first)
first= 0;
else
str->append(',');
item->print_item_w_name(str);
}
/*
from clause
TODO: support USING/FORCE/IGNORE index
*/
if (table_list.elements)
{
str->append(" from ");
Item *next_on= 0;
for (TABLE_LIST *table= (TABLE_LIST *) table_list.first;
table;
table= table->next)
{
if (table->derived)
{
str->append('(');
table->derived->print(str);
str->append(") ");
str->append(table->alias);
}
else
{
str->append(table->db);
str->append('.');
str->append(table->real_name);
if (strcmp(table->real_name, table->alias))
{
str->append(' ');
str->append(table->alias);
}
}
if (table->on_expr && ((table->outer_join & JOIN_TYPE_LEFT) ||
!(table->outer_join & JOIN_TYPE_RIGHT)))
next_on= table->on_expr;
if (next_on)
{
str->append(" on(");
next_on->print(str);
str->append(')');
next_on= 0;
}
TABLE_LIST *next;
if ((next= table->next))
{
if (table->outer_join & JOIN_TYPE_RIGHT)
{
str->append(" right join ");
if (!(table->outer_join & JOIN_TYPE_LEFT) &&
table->on_expr)
next_on= table->on_expr;
}
else if (next->straight)
str->append(" straight_join ");
else if (next->outer_join & JOIN_TYPE_LEFT)
str->append(" left join ");
else
str->append(" join ");
}
}
}
//where
Item *where= this->where;
if (join)
where= join->conds;
if (where)
{
str->append(" where ");
where->print(str);
}
//group by & olap
if (group_list.elements)
{
str->append(" group by ");
print_order(str, (ORDER *) group_list.first);
switch (olap)
{
case CUBE_TYPE:
str->append(" with cube");
break;
case ROLLUP_TYPE:
str->append(" with rollup");
break;
default:
; //satisfy compiler
}
}
//having
Item *having= this->having;
if (join)
having= join->having;
if (having)
{
str->append(" having ");
having->print(str);
}
if (order_list.elements)
{
str->append(" order by ");
print_order(str, (ORDER *) order_list.first);
}
// limit
print_limit(thd, str);
// PROCEDURE unsupported here
}