diff options
Diffstat (limited to 'sql/item.cc')
| -rw-r--r-- | sql/item.cc | 34 |
1 files changed, 25 insertions, 9 deletions
diff --git a/sql/item.cc b/sql/item.cc index ad8b79182d4..27cb6d49fd4 100644 --- a/sql/item.cc +++ b/sql/item.cc @@ -1424,7 +1424,8 @@ bool agg_item_charsets(DTCollation &coll, const char *fname, In case we're in statement prepare, create conversion item in its memory: it will be reused on each execute. */ - arena= thd->activate_stmt_arena_if_needed(&backup); + arena= thd->is_stmt_prepare() ? thd->activate_stmt_arena_if_needed(&backup) + : NULL; for (i= 0, arg= args; i < nargs; i++, arg+= item_sep) { @@ -1459,7 +1460,7 @@ bool agg_item_charsets(DTCollation &coll, const char *fname, been created in prepare. In this case register the change for rollback. */ - if (arena && arena->is_conventional()) + if (arena) *arg= conv; else thd->change_item_tree(arg, conv); @@ -3903,7 +3904,9 @@ Field *Item::make_string_field(TABLE *table) if (max_length/collation.collation->mbmaxlen > CONVERT_IF_BIGGER_TO_BLOB) return new Field_blob(max_length, maybe_null, name, table, collation.collation); - if (max_length > 0) + /* Item_type_holder holds the exact type, do not change it */ + if (max_length > 0 && + (type() != Item::TYPE_HOLDER || field_type() != MYSQL_TYPE_STRING)) return new Field_varstring(max_length, maybe_null, name, table, collation.collation); return new Field_string(max_length, maybe_null, name, table, @@ -3967,6 +3970,7 @@ Field *Item::tmp_table_field_from_field_type(TABLE *table) case MYSQL_TYPE_TIME: return new Field_time(maybe_null, name, table, &my_charset_bin); case MYSQL_TYPE_TIMESTAMP: + return new Field_timestamp(maybe_null, name, table, &my_charset_bin); case MYSQL_TYPE_DATETIME: return new Field_datetime(maybe_null, name, table, &my_charset_bin); case MYSQL_TYPE_YEAR: @@ -3990,7 +3994,11 @@ Field *Item::tmp_table_field_from_field_type(TABLE *table) case MYSQL_TYPE_LONG_BLOB: case MYSQL_TYPE_BLOB: case MYSQL_TYPE_GEOMETRY: - return new Field_blob(max_length, maybe_null, name, table, + if (this->type() == Item::TYPE_HOLDER) + return new Field_blob(max_length, maybe_null, name, table, + collation.collation, 1); + else + return new Field_blob(max_length, maybe_null, name, table, collation.collation); break; // Blob handled outside of case } @@ -6053,14 +6061,13 @@ bool Item_type_holder::join_types(THD *thd, Item *item) max_length= my_decimal_precision_to_length(precision, decimals, unsigned_flag); } - else - max_length= max(max_length, display_length(item)); - + switch (Field::result_merge_type(fld_type)) { case STRING_RESULT: { const char *old_cs, *old_derivation; + uint32 old_max_chars= max_length / collation.collation->mbmaxlen; old_cs= collation.collation->name; old_derivation= collation.derivation_name(); if (collation.aggregate(item->collation, MY_COLL_ALLOW_CONV)) @@ -6072,6 +6079,14 @@ bool Item_type_holder::join_types(THD *thd, Item *item) "UNION"); DBUG_RETURN(TRUE); } + /* + To figure out max_length, we have to take into account possible + expansion of the size of the values because of character set + conversions. + */ + max_length= max(old_max_chars * collation.collation->mbmaxlen, + display_length(item) / item->collation.collation->mbmaxlen * + collation.collation->mbmaxlen); break; } case REAL_RESULT: @@ -6090,7 +6105,8 @@ bool Item_type_holder::join_types(THD *thd, Item *item) max_length= (fld_type == MYSQL_TYPE_FLOAT) ? FLT_DIG+6 : DBL_DIG+7; break; } - default:; + default: + max_length= max(max_length, display_length(item)); }; maybe_null|= item->maybe_null; get_full_info(item); @@ -6151,7 +6167,7 @@ uint32 Item_type_holder::display_length(Item *item) case MYSQL_TYPE_DOUBLE: return 53; case MYSQL_TYPE_NULL: - return 4; + return 0; case MYSQL_TYPE_LONGLONG: return 20; case MYSQL_TYPE_INT24: |