SQL查询，空值数（每列）

Question

我有一个名为Hafizwala的表，其中包含农民姓名，害虫种群1，害虫种群2，播种日期等属性。我必须为以下内容编写查询：

没有。 nulls（对于每一列）

我该怎么写这个查询???

Answer 1

请尝试一下，希望它有用

  SELECT COUNT(*)-COUNT(Farmer_Name) As [Farmer Name], COUNT(*)-COUNT(Pest_Population1) As [Pest Population1],
   COUNT(*)-COUNT(Pest_Population2) As  [Pest Population2], COUNT(*)-COUNT(dated) As  [dated]
FROM Hafizwala 

Answer 2

试试这个

SELECT CASE WHEN Name IS NULL THEN 1 ELSE 0 END +
    CASE WHEN pest_popu1 IS NULL THEN 1 ELSE 0 END +       
    CASE WHEN pest_popu2 IS NULL THEN 1 ELSE 0 END +       
    CASE WHEN sowing_date IS NULL THEN 1 ELSE 0 END 

from table_name