diff options
Diffstat (limited to 'sql/item.cc')
| -rw-r--r-- | sql/item.cc | 113 |
1 files changed, 112 insertions, 1 deletions
diff --git a/sql/item.cc b/sql/item.cc index 1d43351688b..c26e00456b7 100644 --- a/sql/item.cc +++ b/sql/item.cc @@ -312,7 +312,7 @@ void Item_field::set_field(Field *field_par) const char *Item_ident::full_name() const { char *tmp; - if (!table_name) + if (!table_name || !field_name) return field_name ? field_name : name ? name : "tmp_field"; if (db_name && db_name[0]) { @@ -1881,6 +1881,8 @@ void Item_cache_str::store(Item *item) } collation.set(item->collation); } + + double Item_cache_str::val() { int err; @@ -1890,6 +1892,8 @@ double Item_cache_str::val() else return (double)0; } + + longlong Item_cache_str::val_int() { int err; @@ -1900,6 +1904,7 @@ longlong Item_cache_str::val_int() return (longlong)0; } + bool Item_cache_row::allocate(uint num) { item_count= num; @@ -1908,6 +1913,7 @@ bool Item_cache_row::allocate(uint num) (Item_cache **) thd->calloc(sizeof(Item_cache *)*item_count))); } + bool Item_cache_row::setup(Item * item) { example= item; @@ -1924,6 +1930,7 @@ bool Item_cache_row::setup(Item * item) return 0; } + void Item_cache_row::store(Item * item) { null_value= 0; @@ -1935,6 +1942,7 @@ void Item_cache_row::store(Item * item) } } + void Item_cache_row::illegal_method_call(const char *method) { DBUG_ENTER("Item_cache_row::illegal_method_call"); @@ -1944,6 +1952,7 @@ void Item_cache_row::illegal_method_call(const char *method) DBUG_VOID_RETURN; } + bool Item_cache_row::check_cols(uint c) { if (c != item_count) @@ -1954,6 +1963,7 @@ bool Item_cache_row::check_cols(uint c) return 0; } + bool Item_cache_row::null_inside() { for (uint i= 0; i < item_count; i++) @@ -1973,6 +1983,7 @@ bool Item_cache_row::null_inside() return 0; } + void Item_cache_row::bring_value() { for (uint i= 0; i < item_count; i++) @@ -1980,6 +1991,106 @@ void Item_cache_row::bring_value() return; } + +Item_type_holder::Item_type_holder(THD *thd, Item *item) + :Item(thd, *item), item_type(item->result_type()) +{ + DBUG_ASSERT(item->fixed); + + /* + It is safe assign pointer on field, because it will be used just after + all JOIN::prepare calls and before any SELECT execution + */ + if (item->type() == Item::FIELD_ITEM) + field_example= ((Item_field*) item)->field; + else + field_example= 0; +} + + +// STRING_RESULT, REAL_RESULT, INT_RESULT, ROW_RESULT +static Item_result type_convertor[4][4]= +{{STRING_RESULT, STRING_RESULT, STRING_RESULT, ROW_RESULT}, + {STRING_RESULT, REAL_RESULT, REAL_RESULT, ROW_RESULT}, + {STRING_RESULT, REAL_RESULT, INT_RESULT, ROW_RESULT}, + {ROW_RESULT, ROW_RESULT, ROW_RESULT, ROW_RESULT}}; + +void Item_type_holder::join_types(THD *thd, Item *item) +{ + bool change_field= 0, skip_store_field= 0; + Item_result new_type= type_convertor[item_type][item->result_type()]; + + // we have both fields + if (field_example && item->type() == Item::FIELD_ITEM) + { + Field *field= ((Item_field *)item)->field; + if (field_example->field_cast_type() != field->field_cast_type()) + { + if (!(change_field= + field_example->field_cast_compatible(field->field_cast_type()))) + { + /* + if old field can't store value of 'worse' new field we will make + decision about result field type based only on Item result type + */ + if (!field->field_cast_compatible(field_example->field_cast_type())) + skip_store_field= 1; + } + } + } + + // size/type should be changed + if (change_field || + (new_type != item_type) || + (max_length < item->max_length) || + ((new_type == INT_RESULT) && + (decimals < item->decimals)) || + (!maybe_null && item->maybe_null)) + { + // new field has some parameters worse then current + skip_store_field|= (change_field && + (max_length > item->max_length) || + ((new_type == INT_RESULT) && + (decimals > item->decimals)) || + (maybe_null && !item->maybe_null)); + /* + It is safe assign pointer on field, because it will be used just after + all JOIN::prepare calls and before any SELECT execution + */ + if (skip_store_field || item->type() != Item::FIELD_ITEM) + field_example= 0; + else + field_example= ((Item_field*) item)->field; + + max_length= max(max_length, item->max_length); + decimals= max(decimals, item->decimals); + maybe_null|= item->maybe_null; + item_type= new_type; + } + DBUG_ASSERT(item_type != ROW_RESULT); +} + + +double Item_type_holder::val() +{ + DBUG_ASSERT(0); // should never be called + return 0.0; +} + + +longlong Item_type_holder::val_int() +{ + DBUG_ASSERT(0); // should never be called + return 0; +} + + +String *Item_type_holder::val_str(String*) +{ + DBUG_ASSERT(0); // should never be called + return 0; +} + /***************************************************************************** ** Instantiate templates *****************************************************************************/ |