Question

这是我的桌子：

我需要获取每个每个Callid的元素名称计数，其中varname等于'eCounter'并且varvalue最大。

这些表通过元素标识一个（元素）与许多（元素细节）相关。我包括了实际elementid的格式，因此您不要假设它们是连续的数字。

我尝试下面的代码只是为了获得每次调用的最大varvalue / elementid，但这也没有解决。

选择MAX（a.varvalue）作为MAXvarvalue，b.callgui FROM elementdetail AS a，元素AS b 在（a.elementid = b.elementid）和（a.varname ='eCounter'） GROUP BY变量名，callguid

这就是我需要的结果看起来像的样子。

Answer 1

使用最新的Informix版本（14.10.XC1）。

假设有以下表格：

CREATE TABLE element
(
    callid      INTEGER,
    elementid   BIGINT,
    elementname CHAR( 20 )
);

CREATE TABLE elementdetail
(
    elementid   BIGINT,
    varname     CHAR( 20 ),
    varvalue    INTEGER
);

其中填充了示例数据（进行救援的OCR，您确实应该将示例数据和表格以文本形式发布，而不是以图片形式发布）：

INSERT INTO element VALUES ( 1, 1001901560322810000, 'set_Page1' );
INSERT INTO element VALUES ( 1, 1001921560322810000, 'set_Page5' );
INSERT INTO element VALUES ( 1, 1001181560322820000, 'set_Page4' );
INSERT INTO element VALUES ( 1, 1001021560322820000, 'set_Page3' );
INSERT INTO element VALUES ( 1, 1001331560322830000, 'set_Page6' );
INSERT INTO element VALUES ( 2, 1002281560322920000, 'set_Page1' );
INSERT INTO element VALUES ( 2, 1002301560322920000, 'set_Page5' );
INSERT INTO element VALUES ( 2, 1002881560322940000, 'set_Page4' );
INSERT INTO element VALUES ( 3, 1002271560322950000, 'set_Page1' );
INSERT INTO element VALUES ( 3, 1002951560322970000, 'set_Page4' );
INSERT INTO element VALUES ( 3, 1002231560322980000, 'set_Page6' );
INSERT INTO element VALUES ( 4, 1002781560323000000, 'set_Page1' );
INSERT INTO element VALUES ( 4, 1002891560323020000, 'set_Page5' );
INSERT INTO element VALUES ( 4, 1002391560323040000, 'set_Page4' );

INSERT INTO elementdetail VALUES ( 1001901560322810000, 'eCounter', 0 );
INSERT INTO elementdetail VALUES ( 1001901560322810000, 'other_variables', NULL );
INSERT INTO elementdetail VALUES ( 1001921560322810000, 'eCounter', 1 );
INSERT INTO elementdetail VALUES ( 1001921560322810000, 'other_variables', NULL );
INSERT INTO elementdetail VALUES ( 1001181560322820000, 'eCounter', 2 );
INSERT INTO elementdetail VALUES ( 1001181560322820000, 'other_variables', NULL );
INSERT INTO elementdetail VALUES ( 1001021560322820000, 'eCounter', 4 );
INSERT INTO elementdetail VALUES ( 1001021560322820000, 'other_variables', NULL );
INSERT INTO elementdetail VALUES ( 1001331560322830000, 'eCounter', 5 );
INSERT INTO elementdetail VALUES ( 1001331560322830000, 'other_variables', NULL );
INSERT INTO elementdetail VALUES ( 1002281560322920000, 'eCounter', 0 );
INSERT INTO elementdetail VALUES ( 1002281560322920000, 'other_variables', NULL );
INSERT INTO elementdetail VALUES ( 1002301560322920000, 'eCounter', 1 );
INSERT INTO elementdetail VALUES ( 1002301560322920000, 'other_variables', NULL );
INSERT INTO elementdetail VALUES ( 1002881560322940000, 'eCounter', 2 );
INSERT INTO elementdetail VALUES ( 1002881560322940000, 'other_variables', NULL );
INSERT INTO elementdetail VALUES ( 1002271560322950000, 'eCounter', 0 );
INSERT INTO elementdetail VALUES ( 1002271560322950000, 'other_variables', NULL );
INSERT INTO elementdetail VALUES ( 1002951560322970000, 'eCounter', 1 );
INSERT INTO elementdetail VALUES ( 1002951560322970000, 'other_variables', NULL );
INSERT INTO elementdetail VALUES ( 1002231560322980000, 'eCounter', 2 );
INSERT INTO elementdetail VALUES ( 1002231560322980000, 'other_variables', NULL );
INSERT INTO elementdetail VALUES ( 1002781560323000000, 'eCounter', 0 );
INSERT INTO elementdetail VALUES ( 1002781560323000000, 'other_variables', NULL );
INSERT INTO elementdetail VALUES ( 1002891560323020000, 'eCounter', 1 );
INSERT INTO elementdetail VALUES ( 1002891560323020000, 'other_variables', NULL );
INSERT INTO elementdetail VALUES ( 1002391560323040000, 'eCounter', 2 );
INSERT INTO elementdetail VALUES ( 1002391560323040000, 'other_variables', NULL );

我们可以利用CTE做这样的事情：

WITH cte_element AS
(
    SELECT
        e.callid,
        e.elementname,
        d.varvalue
    FROM
        element AS e
    INNER JOIN
        elementdetail AS d
    ON
        e.elementid = d.elementid
    WHERE
        d.varname = 'eCounter'
    ORDER BY
        e.callid,
        d.varvalue
) 
SELECT
    vt1.elementname,
    COUNT( vt1.elementname ) AS count_elementname
FROM
(
    SELECT
        tmp1.callid,
        tmp1.elementname,
        tmp1.varvalue
    FROM
        cte_element AS tmp1
    WHERE
        tmp1.varvalue = 
        (
            SELECT 
                MAX( tmp2.varvalue )
            FROM
                cte_element AS tmp2
            WHERE
                tmp1.callid = tmp2.callid
            GROUP BY
                tmp2.callid
        )
) AS vt1
GROUP BY
    vt1.elementname
;

-- Results
elementname          count_elementname

set_Page6                            2
set_Page4                            2

仍然使用Informix的最新版本，使用窗口而不是CTE：

SELECT
    vt1.elementname,
    COUNT( vt1.elementname ) AS count_elementname
FROM
(
SELECT
    e.callid,
    e.elementname,
    d.varvalue,
    RANK() OVER 
    ( 
        PARTITION BY e.callid ORDER BY e.callid, d.varvalue DESC 
    ) AS rank
FROM
    element AS e
INNER JOIN
    elementdetail AS d
ON
    e.elementid = d.elementid
WHERE
    d.varname = 'eCounter'
ORDER BY
    e.callid,
    d.varvalue
) AS vt1
WHERE
    vt1.rank = 1
GROUP BY
    vt1.elementname
;

-- Results
elementname          count_elementname

set_Page6                            2
set_Page4                            2

对于较旧的Informix版本，没有CTE或窗口，因此我们使用一个临时表：

SELECT
    e.callid,
    e.elementname,
    d.varvalue
FROM
    element AS e
INNER JOIN
    elementdetail AS d
ON
    e.elementid = d.elementid
WHERE
    d.varname = 'eCounter'
ORDER BY
    e.callid,
    d.varvalue
INTO TEMP temp_element 
;

SELECT
    vt1.elementname,
    COUNT( vt1.elementname ) AS count_elementname
FROM
(
    SELECT
        tmp1.callid,
        tmp1.elementname,
        tmp1.varvalue
    FROM
        temp_element AS tmp1
    WHERE
        tmp1.varvalue = 
        (
            SELECT 
                MAX( tmp2.varvalue )
            FROM
                temp_element AS tmp2
            WHERE
                tmp1.callid = tmp2.callid
            GROUP BY
                tmp2.callid
        )
) AS vt1
GROUP BY
    vt1.elementname
;

-- Results
elementname          count_elementname

set_Page6                            2
set_Page4                            2

我不知道当您使用更健壮的数据集（每个表上成千上万个行）时，这些查询将如何扩展。

例如，当callid具有2个elementname且具有相同的eCounter varvalue值时，我没有测试过任何极端情况。

INFORMIX：来自不同callid和Max变量值的子查询中每个元素名称的计数

1 个答案: