diff options
Diffstat (limited to 'sql/sql_lex.h')
| -rw-r--r-- | sql/sql_lex.h | 46 |
1 files changed, 41 insertions, 5 deletions
diff --git a/sql/sql_lex.h b/sql/sql_lex.h index e8c65ba5100..2240f504290 100644 --- a/sql/sql_lex.h +++ b/sql/sql_lex.h @@ -472,14 +472,16 @@ class st_select_lex: public st_select_lex_node { public: Name_resolution_context context; - char *db, *db1, *table1, *db2, *table2; /* For outer join using .. */ + char *db; Item *where, *having; /* WHERE & HAVING clauses */ Item *prep_where; /* saved WHERE clause for prepared statement processing */ /* point on lex in which it was created, used in view subquery detection */ st_lex *parent_lex; enum olap_type olap; - SQL_LIST table_list, group_list; /* FROM & GROUP BY clauses */ - List<Item> item_list; /* list of fields & expressions */ + /* FROM clause - points to the beginning of the TABLE_LIST::next_local list. */ + SQL_LIST table_list; + SQL_LIST group_list; /* GROUP BY clause. */ + List<Item> item_list; /* list of fields & expressions */ List<String> interval_list, use_index, *use_index_ptr, ignore_index, *ignore_index_ptr; /* @@ -492,7 +494,12 @@ public: List<TABLE_LIST> top_join_list; /* join list of the top level */ List<TABLE_LIST> *join_list; /* list for the currently parsed join */ TABLE_LIST *embedding; /* table embedding to the above list */ - TABLE_LIST *leaf_tables; /* list of leaves in join table tree */ + /* + Beginning of the list of leaves in a FROM clause, where the leaves + inlcude all base tables including view tables. The tables are connected + by TABLE_LIST::next_leaf, so leaf_tables points to the left-most leaf. + */ + TABLE_LIST *leaf_tables; const char *type; /* type of select for EXPLAIN */ SQL_LIST order_list; /* ORDER clause */ @@ -594,7 +601,6 @@ public: bool init_nested_join(THD *thd); TABLE_LIST *end_nested_join(THD *thd); TABLE_LIST *nest_last_join(THD *thd); - void save_names_for_using_list(TABLE_LIST *tab1, TABLE_LIST *tab2); void add_joined_table(TABLE_LIST *table); TABLE_LIST *convert_right_join(); List<Item>* get_item_list(); @@ -736,6 +742,21 @@ typedef struct st_lex List<set_var_base> var_list; List<Item_param> param_list; List<LEX_STRING> view_list; // view list (list of field names in view) + /* + A stack of name resolution contexts for the query. This stack is used + at parse time to set local name resolution contexts for various parts + of a query. For example, in a JOIN ... ON (some_condition) clause the + Items in 'some_condition' must be resolved only against the operands + of the the join, and not against the whole clause. Similarly, Items in + subqueries should be resolved against the subqueries (and outer queries). + The stack is used in the following way: when the parser detects that + all Items in some clause need a local context, it creates a new context + and pushes it on the stack. All newly created Items always store the + top-most context in the stack. Once the parser leaves the clause that + required a local context, the parser pops the top-most context. + */ + List<Name_resolution_context> context_stack; + SQL_LIST proc_list, auxilliary_table_list, save_list; create_field *last_field; udf_func udf; @@ -927,6 +948,21 @@ typedef struct st_lex return ( query_tables_own_last ? *query_tables_own_last : 0); } void cleanup_after_one_table_open(); + + void push_context(Name_resolution_context *context) + { + context_stack.push_front(context); + } + + void pop_context() + { + context_stack.pop(); + } + + Name_resolution_context *current_context() + { + return context_stack.head(); + } } LEX; struct st_lex_local: public st_lex |