Fixed bug#12185: Data type aggregation may produce wrong result
The Item::tmp_table_field_from_field_type() function creates Field_datetime object instead of Field_timestamp object for timestamp field thus always changing data type is a tmp table is used. The Field_blob object constructor which is used in the Item::tmp_table_field_from_field_type() is always setting packlength field of newly created blob to 4. This leads to changing fields data type for example from the blob to the longblob if a temporary table is used. The Item::make_string_field() function always converts Field_string objects to Field_varstring objects. This leads to changing data type from the char/binary to varchar/varbinary. Added appropriate Field_timestamp object constructor for using in the Item::tmp_table_field_from_field_type() function. Added Field_blob object constructor which sets pack length according to max_length argument. The Item::tmp_table_field_from_field_type() function now creates Field_timestamp object for a timestamp field. The Item_type_holder::display_length() now returns correct NULL length NULL length. The Item::make_string_field() function now doesn't change Field_string to Field_varstring in the case of Item_type_holder. The Item::tmp_table_field_from_field_type() function now uses the Field_blob constructor which sets packlength according to max_length.
Showing
Please register or sign in to comment