Aggregating Pivoted Views over Multiple Fields with Boolean Values
Introduction
In this article, we will explore a SQL problem involving aggregating pivoted views over multiple fields with boolean values. The goal is to create a view that displays the count of product IDs for each pair of attributes, where each attribute has binary values indicating availability or not.
Problem Statement
Given a source table containing different attributes of footwear in multiple boolean fields, we need to create an aggregated pivot view of the availability for each pair of attributes. The cell value should indicate the count of product IDs at the intersection of the given pair.
Sample Data
The sample data provided consists of a table with various attributes of footwear, including s_7, s_8, s_9, s_10, c_white, c_black, c_blue, c_brown, c_other, t_shoes, t_sandals, and t_slippers. Each attribute has binary values (1 = available, 0 = not available) for each product ID.
Desired Output
The desired output is a table with the attributes as columns and the count of product IDs for each pair of attributes as rows. For example, the count of product IDs with s_8 and c_black should be displayed in the intersection cell.
SQL Solution
To solve this problem, we can use a query that involves UNION ALL operations to combine multiple SELECT statements. Here’s an example SQL query:
SELECT 's_7' `attribute`, SUM(`s_7` = 1) `s_7`, SUM(`s_8` = 1) `s_8`, SUM(`s_9` = 1) `s_9`, SUM(`s_10` = 1) `s_10`, SUM(`c_white` = 1) `c_white`, SUM(`c_black` = 1) `c_black`, SUM(`c_blue` = 1) `c_blue`, SUM(`c_brown` = 1) `c_brown`, SUM(`c_other` = 1) `c_other`, SUM(`t_shoes` = 1) `t_shoes`, SUM(`t_sandals` = 1) `t_sandals`, SUM(`t_slippers` = 1) `t_slippers`
FROM t1
WHERE `s_7` = 1
UNION ALL
SELECT 's_8' `attribute`, SUM(`s_7` = 1) `s_7`, SUM(`s_8` = 1) `s_8`, SUM(`s_9` = 1) `s_9`, SUM(`s_10` = 1) `s_10`, SUM(`c_white` = 1) `c_white`, SUM(`c_black` = 1) `c_black`, SUM(`c_blue` = 1) `c_blue`, SUM(`c_brown` = 1) `c_brown`, SUM(`c_other` = 1) `c_other`, SUM(`t_shoes` = 1) `t_shoes`, SUM(`t_sandals` = 1) `t_sandals`, SUM(`t_slippers` = 1) `t_slippers`
FROM t1
WHERE `s_8` = 1
UNION ALL
SELECT 's_9' `attribute`, SUM(`s_7` = 1) `s_7`, SUM(`s_8` = 1) `s_8`, SUM(`s_9` = 1) `s_9`, SUM(`s_10` = 1) `s_10`, SUM(`c_white` = 1) `c_white`, SUM(`c_black` = 1) `c_black`, SUM(`c_blue` = 1) `c_blue`, SUM(`c_brown` = 1) `c_brown`, SUM(`c_other` = 1) `c_other`, SUM(`t_shoes` = 1) `t_shoes`, SUM(`t_sandals` = 1) `t_sandals`, SUM(`t_slippers` = 1) `t_slippers`
FROM t1
WHERE `s_9` = 1
UNION ALL
SELECT 's_10' `attribute`, SUM(`s_7` = 1) `s_7`, SUM(`s_8` = 1) `s_8`, SUM(`s_9` = 1) `s_9`, SUM(`s_10` = 1) `s_10`, SUM(`c_white` = 1) `c_white`, SUM(`c_black` = 1) `c_black`, SUM(`c_blue` = 1) `c_blue`, SUM(`c_brown` = 1) `c_brown`, SUM(`c_other` = 1) `c_other`, SUM(`t_shoes` = 1) `t_shoes`, SUM(`t_sandals` = 1) `t_sandals`, SUM(`t_slippers` = 1) `t_slippers`
FROM t1
WHERE `s_10` = 1
UNION ALL
SELECT 'c_white' `attribute`, SUM(`s_7` = 1) `s_7`, SUM(`s_8` = 1) `s_8`, SUM(`s_9` = 1) `s_9`, SUM(`s_10` = 1) `s_10`, SUM(`c_white` = 1) `c_white`, SUM(`c_black` = 1) `c_black`, SUM(`c_blue` = 1) `c_blue`, SUM(`c_brown` = 1) `c_brown`, SUM(`c_other` = 1) `c_other`, SUM(`t_shoes` = 1) `t_shoes`, SUM(`t_sandals` = 1) `t_sandals`, SUM(`t_slippers` = 1) `t_slippers`
FROM t1
WHERE 'c_white' = 1
UNION ALL
SELECT 'c_black' `attribute`, SUM(`s_7` = 1) `s_7`, SUM(`s_8` = 1) `s_8`, SUM(`s_9` = 1) `s_9`, SUM(`s_10` = 1) `s_10`, SUM(`c_black` = 1) `c_black`, SUM(`c_blue` = 1) `c_blue`, SUM(`c_brown` = 1) `c_brown`, SUM(`c_other` = 1) `c_other`, SUM(`t_shoes` = 1) `t_shoes`, SUM(`t_sandals` = 1) `t_sandals`, SUM(`t_slippers` = 1) `t_slippers`
FROM t1
WHERE 'c_black' = 1
UNION ALL
SELECT 'c_blue' `attribute`, SUM(`s_7` = 1) `s_7`, SUM(`s_8` = 1) `s_8`, SUM(`s_9` = 1) `s_9`, SUM(`s_10` = 1) `s_10`, SUM(`c_blue` = 1) `c_blue`, SUM(`c_brown` = 1) `c_brown`, SUM(`c_other` = 1) `c_other`, SUM(`t_shoes` = 1) `t_shoes`, SUM(`t_sandals` = 1) `t_sandals`, SUM(`t_slippers` = 1) `t_slippers`
FROM t1
WHERE 'c_blue' = 1
UNION ALL
SELECT 'c_brown' `attribute`, SUM(`s_7` = 1) `s_7`, SUM(`s_8` = 1) `s_8`, SUM(`s_9` = 1) `s_9`, SUM(`s_10` = 1) `s_10`, SUM(`c_brown` = 1) `c_brown`, SUM(`c_other` = 1) `c_other`, SUM(`t_shoes` = 1) `t_shoes`, SUM(`t_sandals` = 1) `t_sandals`, SUM(`t_slippers` = 1) `t_slippers`
FROM t1
WHERE 'c_brown' = 1
UNION ALL
SELECT 'c_other' `attribute`, SUM(`s_7` = 1) `s_7`, SUM(`s_8` = 1) `s_8`, SUM(`s_9` = 1) `s_9`, SUM(`s_10` = 1) `s_10`, SUM(`c_other` = 1) `c_other`, SUM(`t_shoes` = 1) `t_shoes`, SUM(`t_sandals` = 1) `t_sandals`, SUM(`t_slippers` = 1) `t_slippers`
FROM t1
WHERE 'c_other' = 1
UNION ALL
SELECT 't_shoes' `attribute`, SUM(`s_7` = 1) `s_7`, SUM(`s_8` = 1) `s_8`, SUM(`s_9` = 1) `s_9`, SUM(`s_10` = 1) `s_10`, SUM(`t_shoes` = 1) `t_shoes`, SUM(`t_sandals` = 1) `t_sandals`, SUM(`t_slippers` = 1) `t_slippers`
FROM t1
WHERE 't_shoes' = 1
UNION ALL
SELECT 't_sandals' `attribute`, SUM(`s_7` = 1) `s_7`, SUM(`s_8` = 1) `s_8`, SUM(`s_9` = 1) `s_9`, SUM(`s_10` = 1) `s_10`, SUM(`t_sandals` = 1) `t_sandals`, SUM(`t_shoes` = 1) `t_shoes`, SUM(`t_slippers` = 1) `t_slippers`
FROM t1
WHERE 't_sandals' = 1
UNION ALL
SELECT 't_slippers' `attribute`, SUM(`s_7` = 1) `s_7`, SUM(`s_8` = 1) `s_8`, SUM(`s_9` = 1) `s_9`, SUM(`s_10` = 1) `s_10`, SUM(`t_slippers` = 1) `t_slippers`, SUM(`t_shoes` = 1) `t_shoes`, SUM(`t_sandals` = 1) `t_sandals`
FROM t1
WHERE 't_slippers' = 1;
This query uses UNION ALL to combine multiple SELECT statements, each selecting a different attribute. The SUM function is used to count the number of rows where the attribute is equal to 1.
Example Solution in PHP
Here’s an example solution in PHP that generates the SQL query dynamically:
$attributes = ['s_7', 's_8', 's_9', 's_10', 'c_white', 'c_black', 'c_blue', 'c_brown', 'c_other', 't_shoes', 't_sandals', 't_slippers'];
$sql = '';
foreach ($attributes as $attribute) {
if ($sql) {
$sql .= ' UNION ALL ';
}
$sql .= "SELECT '$attribute' `attribute`";
foreach ($attributes as $attr) {
$sql .= ", SUM(`$attr` = 1) `$attr'";
}
$sql .= " FROM t1 WHERE `$attribute` = 1";
}
echo $sql;
This PHP code loops through the list of attributes and generates the SQL query dynamically. The UNION ALL operator is used to combine multiple SELECT statements, each selecting a different attribute.
Conclusion
In this article, we explored a SQL problem involving aggregating pivoted views over multiple fields with boolean values. We provided a solution using UNION ALL operations and demonstrated how to generate the SQL query dynamically in PHP.
Last modified on 2024-09-13