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Fix of LP BUG#777809

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There are 2 volatile condition constructions AND/OR constructions and fields(references) when first
good supported to be top elements of conditions because it is normal practice
(see copy_andor_structure for example) fields without any expression in the condition is really rare
and mostly useless case however it could lead to problems when optimiser changes/moves them unaware
of other variables referring to them. An easy solution of this problem is just to replace single field
in a condition with equivalent expression well supported by the server (<field> -> <field> != 0).

mysql-test/r/view.result:
  New test added.
mysql-test/t/view.test:
  New test added.
sql/sql_parse.cc:
  <field> -> <field> != 0
sql/sql_yacc.yy:
  <field> -> <field> != 0
This commit is contained in:
unknown
2011-07-21 11:20:55 +03:00
parent 541469f7cb
commit 20a2e1d0ac
4 changed files with 63 additions and 3 deletions
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23
sql/sql_parse.cc
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@ -6890,6 +6890,28 @@ push_new_name_resolution_context(THD *thd,
}
/**
Fix condition which contains only field (f turns to f <> 0 )
@param cond The condition to fix
@return fixed condition
*/
Item *normalize_cond(Item *cond)
{
if (cond)
{
Item::Type type= cond->type();
if (type == Item::FIELD_ITEM || type == Item::REF_ITEM)
{
cond= new Item_func_ne(cond, new Item_int(0));
}
}
return cond;
}
/**
Add an ON condition to the second operand of a JOIN ... ON.
@ -6908,6 +6930,7 @@ void add_join_on(TABLE_LIST *b, Item *expr)
{
if (expr)
{
expr= normalize_cond(expr);
if (!b->on_expr)
b->on_expr= expr;
else