merge into 语法

　Oracle中，要实现相同的功能，要用到Merge into来实现（Oracle 9i引入的功能），其语法如下： MERGE INTO table_name alias1 USING (table|view|sub_query) alias2ON (join condition) WHEN MATCHED THEN     UPDATE      SET col1 = col_val1,            col2 = col_val2 WHEN NOT MATCHED THEN     INSERT (column_list) VALUES (column_values);