怎么用SQL 快速判断 24个字段是否为空值

可以使用如下的SQL语句来快速判断24个字段是否为空值：

SELECT 
    CASE WHEN col1 IS NULL THEN 'col1 is null' ELSE '' END AS col1,
    CASE WHEN col2 IS NULL THEN 'col2 is null' ELSE '' END AS col2,
    CASE WHEN col3 IS NULL THEN 'col3 is null' ELSE '' END AS col3,
    CASE WHEN col4 IS NULL THEN 'col4 is null' ELSE '' END AS col4,
    CASE WHEN col5 IS NULL THEN 'col5 is null' ELSE '' END AS col5,
    CASE WHEN col6 IS NULL THEN 'col6 is null' ELSE '' END AS col6,
    CASE WHEN col7 IS NULL THEN 'col7 is null' ELSE '' END AS col7,
    CASE WHEN col8 IS NULL THEN 'col8 is null' ELSE '' END AS col8,
    CASE WHEN col9 IS NULL THEN 'col9 is null' ELSE '' END AS col9,
    CASE WHEN col10 IS NULL THEN 'col10 is null' ELSE '' END AS col10,
    CASE WHEN col11 IS NULL THEN 'col11 is null' ELSE '' END AS col11,
    CASE WHEN col12 IS NULL THEN 'col12 is null' ELSE '' END AS col12,
    CASE WHEN col13 IS NULL THEN 'col13 is null' ELSE '' END AS col13,
    CASE WHEN col14 IS NULL THEN 'col14 is null' ELSE '' END AS col14,
    CASE WHEN col15 IS NULL THEN 'col15 is null' ELSE '' END AS col15,
    CASE WHEN col16 IS NULL THEN 'col16 is null' ELSE '' END AS col16,
    CASE WHEN col17 IS NULL THEN 'col17 is null' ELSE '' END AS col17,
    CASE WHEN col18 IS NULL THEN 'col18 is null' ELSE '' END AS col18,
    CASE WHEN col19 IS NULL THEN 'col19 is null' ELSE '' END AS col19,
    CASE WHEN col20 IS NULL THEN 'col20 is null' ELSE '' END AS col20,
    CASE WHEN col21 IS NULL THEN 'col21 is null' ELSE '' END AS col21,
    CASE WHEN col22 IS NULL THEN 'col22 is null' ELSE '' END AS col22,
    CASE WHEN col23 IS NULL THEN 'col23 is null' ELSE '' END AS col23,
    CASE WHEN col24 IS NULL THEN 'col24 is null' ELSE '' END AS col24
FROM your_table;

这条SQL语句将会返回一个包含24列的结果集，每列为一个字段，如果该字段为空值，则该列的值为该字段名加上" is null"的字符串，否则该列的值为空字符串。你可以根据查询结果来判断哪些字段为空值，哪些字段不为空值。