Question

我是SQLite的新手，已经从数据库中选择了我需要的特定行（也就是缺少值的行）。谁能帮助我开发一个查询，该查询将删除所有未选中的行？到目前为止，我可以选择以下内容：

SELECT * FROM BadData_Table   
WHERE A IS NULL OR A = ''
    OR B IS NULL OR B = ''
    OR C IS NULL OR C = ''
    OR D IS NULL OR D = ''
    OR E IS NULL OR E = ''
    OR F IS NULL OR F = ''
    OR G IS NULL OR G = ''
    OR H IS NULL OR H = ''
    OR I IS NULL OR I = ''
    OR J IS NULL OR J = '';

Answer 1

您可以将运算符NOT应用于整个条件：

DELETE FROM BadData_Table   
WHERE NOT (
       A IS NULL OR A = ''
    OR B IS NULL OR B = ''
    OR C IS NULL OR C = ''
    OR D IS NULL OR D = ''
    OR E IS NULL OR E = ''
    OR F IS NULL OR F = ''
    OR G IS NULL OR G = ''
    OR H IS NULL OR H = ''
    OR I IS NULL OR I = ''
    OR J IS NULL OR J = ''
);

等效于：

DELETE FROM BadData_Table   
WHERE 
        A IS NOT NULL AND A <> ''
    AND B IS NOT NULL AND B <> ''
    AND C IS NOT NULL AND C <> ''
    AND D IS NOT NULL AND D <> ''
    AND E IS NOT NULL AND E <> ''
    AND F IS NOT NULL AND F <> ''
    AND G IS NOT NULL AND G <> ''
    AND H IS NOT NULL AND H <> ''
    AND I IS NOT NULL AND I <> ''
    AND J IS NOT NULL AND J <> ''
;

SQLite从表中删除未选择的行

1 个答案: