使用COALESCE函数填充缺失值。
示例代码:
SELECT COALESCE(Table1.column1, Table2.column1) as column1, COALESCE(Table1.column2, Table2.column2) as column2, COALESCE(Table1.column3, Table2.column3) as column3 FROM Table1 UNION ALL SELECT COALESCE(Table1.column1, Table2.column1) as column1, COALESCE(Table1.column2, Table2.column2) as column2, COALESCE(Table1.column3, Table2.column3) as column3 FROM Table2