How to Get Multiple Counts With a Single Query?
When analyzing data, it is common to need counts of different categories within a dataset. For example, we might want to count the number of orders by region, the number of products in each category or the number of users in each age group.
Manually querying each count separately can be time-consuming and inefficient. Below are the methods that are used to get multiple counts with a single query in PostgreSQL.
- Using CASE Statements and GROUP BY Clause
- Using Subquery
Let’s set up an Environment to Get Multiple Counts With Single Query
To understand How to Get Multiple Counts With Single Query in PostgreSQL we need a table on which we will perform various operations and queries. Here we will consider a table called test which contains id val1 and val2 as Columns.
CREATE TABLE test (
id INT PRIMARY KEY,
val1 VARCHAR(50),
val2 VARCHAR(50)
);
INSERT INTO test VALUES (1, 'type1', 'red');
INSERT INTO test VALUES (2, 'type2', 'red');
INSERT INTO test VALUES (3, 'type3', 'blue');
INSERT INTO test VALUES (4, 'type1', 'green');
INSERT INTO test VALUES (5, 'type2', 'red');
INSERT INTO test VALUES (6, 'type3', 'blue');
INSERT INTO test VALUES (7, 'type1', 'green');
INSERT INTO test VALUES (8, 'type2', 'green');
INSERT INTO test VALUES (9, 'type3', 'red');
INSERT INTO test VALUES (10, 'type1', 'blue');
INSERT INTO test VALUES (11, 'type2', 'red');
INSERT INTO test VALUES (12, 'type3', 'green');
INSERT INTO test VALUES (13, 'type1', 'red');
INSERT INTO test VALUES (14, 'type2', 'green');
INSERT INTO test VALUES (15, 'type3', 'red');
Output:
Explanation: Our table has been created.
How to Get Multiple Counts With Single Query in PostgreSQL?
Efficient data analysis often requires counting occurrences of different categories within a dataset. PostgreSQL, a powerful relational database management system offers a feature that allows us to achieve this efficiently.
In this article, we’ll explore how to Get Multiple Counts With a Single Query using various methods along with examples and so on.
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