PostgreSQL 9.3:使用array_agg函数以特定格式显示结果 [英] PostgreSQL 9.3: Display result in specific format using array_agg function

问题描述

我想将下表中的给定记录显示为特定格式 如下表所示.

I want to show the given records in the following table into the specific format which is shown below in the table.

创建表格:Test_1

CREATE TABLE Test_1
(
ColumnA varchar,
ColumnB varchar
);

插入记录:

INSERT INTO Test_1 values('A101','B101'),('A102','B102'),
            ('A103','B103'),('A104','B104'),
            ('A105','B105'),('A106','B106'),
            ('A107','B107'),('A108','B108'),
            ('A109','B109'),('A201','B201');

我想显示这样的结果:

预期结果:

ColumnA     ColumnX
---------------------------------------------------------------------------------------------------------------------------------------
A101        "B101" =  1, "B102" = 0, "B103" = 0, "B104" = 0, "B105" = 0, "B106" = 0, "B107" = 0, "B108" = 0, "B109" = 0, "B201" = 0
A102        "B101" =  0, "B102" = 1, "B103" = 0, "B104" = 0, "B105" = 0, "B106" = 0, "B107" = 0, "B108" = 0, "B109" = 0, "B201" = 0
A103        "B101" =  0, "B102" = 0, "B103" = 1, "B104" = 0, "B105" = 0, "B106" = 0, "B107" = 0, "B108" = 0, "B109" = 0, "B201" = 0
A104        "B101" =  0, "B102" = 0, "B103" = 0, "B104" = 1, "B105" = 0, "B106" = 0, "B107" = 0, "B108" = 0, "B109" = 0, "B201" = 0
A105        "B101" =  0, "B102" = 0, "B103" = 0, "B104" = 0, "B105" = 1, "B106" = 0, "B107" = 0, "B108" = 0, "B109" = 0, "B201" = 0
A106        "B101" =  0, "B102" = 0, "B103" = 0, "B104" = 0, "B105" = 0, "B106" = 1, "B107" = 0, "B108" = 0, "B109" = 0, "B201" = 0
A107        "B101" =  0, "B102" = 0, "B103" = 0, "B104" = 0, "B105" = 0, "B106" = 0, "B107" = 1, "B108" = 0, "B109" = 0, "B201" = 0
A108        "B101" =  0, "B102" = 0, "B103" = 0, "B104" = 0, "B105" = 0, "B106" = 0, "B107" = 0, "B108" = 1, "B109" = 0, "B201" = 0
A109        "B101" =  0, "B102" = 0, "B103" = 0, "B104" = 0, "B105" = 0, "B106" = 0, "B107" = 0, "B108" = 0, "B109" = 1, "B201" = 0
A201        "B101" =  0, "B102" = 0, "B103" = 0, "B104" = 0, "B105" = 0, "B106" = 0, "B107" = 0, "B108" = 0, "B109" = 0, "B201" = 1

我正在使用以下脚本来完成我的工作:

For which I am using the following script which does my half job:

SELECT columnA, array_agg(ColumnB) AS ColumnX
FROM  (
   SELECT ColumnA, right(ColumnA, -1)::int AS sortb
    , CASE WHEN m.ColumnB IS NULL THEN 0 ELSE 1 END AS ColumnB
   FROM        (SELECT DISTINCT ColumnA FROM Test_1) b
   CROSS  JOIN (SELECT DISTINCT ColumnB FROM Test_1) a
   LEFT   JOIN Test_1 m USING (ColumnA, ColumnB)
   ORDER  BY sortb, right(ColumnB, -1)::int 
   ) sub
GROUP  BY 1, sortb
ORDER  BY sortb;

上面的脚本给了我以下结果:

The above script gives me the following result:

获得结果:

ColumnA          ColumnX
---------------------------------------
A101        {1,0,0,0,0,0,0,0,0,0}
A102        {0,1,0,0,0,0,0,0,0,0}
A103        {0,0,1,0,0,0,0,0,0,0}
A104        {0,0,0,1,0,0,0,0,0,0}
A105        {0,0,0,0,1,0,0,0,0,0}
A106        {0,0,0,0,0,1,0,0,0,0}
A107        {0,0,0,0,0,0,1,0,0,0}
A108        {0,0,0,0,0,0,0,1,0,0}
A109        {0,0,0,0,0,0,0,0,1,0}
A201        {0,0,0,0,0,0,0,0,0,1}

问题:如何在获取ColumnX的值之前添加columnB值?

Question: How to add columnB values infront of values of getting in ColumnX?

推荐答案

这只是一个简单的修改.
还根据您的评论中的要求添加了实际计数.

It's just a simple modification.
Also added the actual count as requested in your comment.

SELECT columnA, array_agg(ColumnB) AS ColumnX
FROM  (
   SELECT ColumnA, right(ColumnA, -1)::int AS sorta
        , '"' || ColumnB || '" = ' || count(m.ColumnB) AS ColumnB
   FROM        (SELECT DISTINCT ColumnA FROM Test_1) b
   CROSS  JOIN (SELECT DISTINCT ColumnB FROM Test_1) a
   LEFT   JOIN Test_1 m USING (ColumnA, ColumnB)
   GROUP  BY ColumnA, ColumnB
   ORDER  BY sorta, right(ColumnB, -1)::int 
   ) sub
GROUP  BY 1, sorta
ORDER  BY sorta;

SQL小提琴.

根据评论:

SELECT ARRAY[columnA] || array_agg(ColumnB) AS ColumnX
FROM  (
   SELECT ColumnA, right(ColumnA, -1)::int AS sorta
        , '"' || ColumnB || '" = ' || count(m.ColumnB) AS ColumnB
   FROM        (SELECT DISTINCT ColumnA FROM Test_1) b
   CROSS  JOIN (SELECT DISTINCT ColumnB FROM Test_1) a
   LEFT   JOIN Test_1 m USING (ColumnA, ColumnB)
   GROUP  BY ColumnA, ColumnB
   ORDER  BY right(ColumnB, -1)::int, sorta
   ) sub
GROUP  BY columnA, sorta
ORDER  BY sorta;

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