当null时忽略where子句列

Question

我有一个SQL，我希望在其中一个排序子句是NUll时在这样的子句中对它进行排序，然后它应该跳过它并转到下一个排序子句

Answer 1

使用coalesce，将下一个排序子句放入当前考虑顺序的列中：

SELECT * FROM table
ORDER BY firstcolumn, COALESCE(second_column_might_be_null, thirdcolumn), thirdcolumn

Answer 2

订单时的用例

order by case when val is not null then yourdeseired
         else val end asc

或者你可以使用合并

order by COALESCE(col1, col2,999999) //here if both column is null then its order value will be 999999 otherwise it will order according to 1st non null column wise