Question

我正在尝试计算一个单词出现在一行的所有列中的次数，这是一个id。

+-------+------+------+------+------+------+------+
| id    | pos1 | pos2 | pos3 | pos4 | pos5 | pos6 |
+-------+------+------+------+------+------+------+
| core1 | AA   | BB   | CC   | HH   | YY   | var1 |
| core2 | AA   | BB   | var3 | TT   | var2 | YY   |
| core5 | AA   | BB   | EE   | GG   | YY   | ZZ   |
+-------+------+------+------+------+------+------+

我已尝试使用此代码但仅返回＆＃39; 1＆＃39;而不是＆＃39; 2＆＃39;这就是我想要的。

SELECT count(id) FROM customize WHERE pos1 OR pos2 OR pos3 OR pos4 OR pos5 OR pos6 LIKE 'var%' AND id = 'core2';

我怎么能这样做？

Answer 1

SELECT 
    (IF(pos1 LIKE 'var%', 1, 0) +
    IF(pos2 LIKE 'var%', 1, 0) +
    IF(pos3 LIKE 'var%', 1, 0) +
    IF(pos4 LIKE 'var%', 1, 0) +
    IF(pos5 LIKE 'var%', 1, 0) +
    IF(pos6 LIKE 'var%', 1, 0)) AS done
FROM customize
WHERE id = 'core2'

Answer 2

可能会加载一个联合查询（每列一个），然后计算结果。

SELECT COUNT(*) 
FROM
(
    SELECT id
    FROM customize 
    WHERE id = 'core2'
    AND pos1 LIKE 'var%'
    UNION ALL
    SELECT id
    FROM customize 
    WHERE id = 'core2'
    AND pos2 LIKE 'var%'
    UNION ALL
    SELECT id
    FROM customize 
    WHERE id = 'core2'
    AND pos3 LIKE 'var%'
    UNION ALL
    SELECT id
    FROM customize 
    WHERE id = 'core2'
    AND pos4 LIKE 'var%'
    UNION ALL
    SELECT id
    FROM customize 
    WHERE id = 'core2'
    AND pos5 LIKE 'var%'
    UNION ALL
    SELECT id
    FROM customize 
    WHERE id = 'core2'
    AND pos6 LIKE 'var%'
)

或者，如果您希望计算具有该值的列的行： -

SELECT COUNT(id)
FROM customize 
WHERE id = 'core2'
AND (pos1 LIKE 'var%' OR pos2 LIKE 'var%' OR pos3 LIKE 'var%' OR pos4 LIKE 'var%' OR pos5 LIKE 'var%' OR pos6 LIKE 'var%')

但更好地规范化您的数据库设计

Answer 3

我想你可能想要更像这样的东西：

    select 
     IF(Pos1 LIKE 'var%', 1, 0) +
     IF(Pos2 LIKE 'var%', 1, 0) +
     IF(Pos3 LIKE 'var%', 1, 0) +
     IF(Pos4 LIKE 'var%', 1, 0) +
     IF(Pos5 LIKE 'var%', 1, 0) +
     IF(Pos6 LIKE 'var%', 1, 0) 
 FROM customize
    where id = 'core2'

Answer 4

尝试从概念上分解问题总是有帮助的。解决这个问题有两个阶段。第一种是转动输入表，将列转换为行。

第二种是计算字符串的值。

这是两个查询（http://sqlfiddle.com/#!2/3731e/7/0）。

SELECT COUNT(*) AS stringcount, pos AS string
FROM (  -- pivot the original table
                  SELECT id, 1 AS i, pos1 AS Pos FROM customize
        UNION ALL SELECT id, 2 AS i, pos2 AS Pos FROM customize
        UNION ALL SELECT id, 3 AS i, pos3 AS Pos FROM customize
        UNION ALL SELECT id, 4 AS i, pos4 AS Pos FROM customize
        UNION ALL SELECT id, 5 AS i, pos5 AS Pos FROM customize
        UNION ALL SELECT id, 6 AS i, pos6 AS Pos FROM customize
) AS pivoted
GROUP BY pos
ORDER BY COUNT(*) DESC, pos

计算行的所有列中的文本重合数

4 个答案: