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MDEV-34189 Unexpected error on WHERE inet6col

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normalize_cond() translated `WHERE col` into `WHERE col<>0`

But the opetator "not equal to 0" does not necessarily exists
for all data types.

For example, the query:

  SELECT * FROM t1 WHERE inet6col;

was translated to:

  SELECT * FROM t1 WHERE inet6col<>0;

which further failed with this error:

  ERROR : Illegal parameter data types inet6 and bigint for operation '<>'

This patch changes the translation from `col<>0` to `col IS TRUE`.
So now
  SELECT * FROM t1 WHERE inet6col;
gets translated to:
  SELECT * FROM t1 WHERE inet6col IS TRUE;

Details:
1. Implementing methods:
   - Field_longstr::val_bool()
   - Field_string::val_bool()
   - Item::val_int_from_val_str()
   If the input contains bad data,
   these methods raise a better error message:
     Truncated incorrect BOOLEAN value
   Before the change, the error was:
     Truncated incorrect DOUBLE value

2. Fixing normalize_cond() to generate Item_func_istrue/Item_func_isfalse
   instances instead of Item_func_ne/Item_func_eq

3. Making Item_func_truth sargable, so it uses the range optimizer.
   Implementing the following methods:
   - get_mm_tree(), get_mm_leaf(), add_key_fields() in Item_func_truth.
   - get_func_mm_tree(), for all Item_func_truth descendants.

4. Implementing the method negated_item() for all Item_func_truth
   descendants, so the negated item has a chance to be sargable:
   For example,
     WHERE NOT col IS NOT FALSE    -- this notation is not sargable
   is now translated to:
     WHERE col IS FALSE            -- this notation is sargable
This commit is contained in:
Alexander Barkov
2024-12-29 12:50:04 +04:00
parent d1ba623677
commit 5a8e6230d7
47 changed files with 1670 additions and 257 deletions
Download Patch File Download Diff File Expand all files Collapse all files

5
sql/sql_parse.cc
View File

@@ -8944,7 +8944,7 @@ Item *normalize_cond(THD *thd, Item *cond)
{
item_base_t is_cond_flag= cond->base_flags & item_base_t::IS_COND;
cond->base_flags&= ~item_base_t::IS_COND;
cond= new (thd->mem_root) Item_func_ne(thd, cond, new (thd->mem_root) Item_int(thd, 0));
cond= new (thd->mem_root) Item_func_istrue(thd, cond);
if (cond)
cond->base_flags|= is_cond_flag;
}
@@ -8958,8 +8958,7 @@ Item *normalize_cond(THD *thd, Item *cond)
Item *arg= func_item->arguments()[0];
if (arg->type() == Item::FIELD_ITEM ||
arg->type() == Item::REF_ITEM)
cond= new (thd->mem_root) Item_func_eq(thd, arg,
new (thd->mem_root) Item_int(thd, 0));
cond= new (thd->mem_root) Item_func_isfalse(thd, arg);
}
}
}