The GROUP BY statement is a powerful tool that facilitates data organization by grouping it according to specific columns specified in the query. This statement is commonly used alongside aggregate functions to summarize data effectively. On the other hand, the ORDER BY clause offers even greater control over result sets, allowing you to arrange them in either ascending or descending order, based on alphabetical or numerical values.
SQL(Structured Query Language) is used for accessing and manipulating databases. Group By and Order By are both clauses of SQL. These are both used to organize data obtained by SQL queries.
Before discussing the difference between GROUP BY and ORDER BY clauses, we will first know about these SQL clauses individually.
ORDER BY clause sorts the result-set of data in ascending or descending order. By default, it sorts the data in ascending order. DESC keyword sorts the result-data set in descending order.
Order By Syntax
SELECT column1_, column2_….
FROM table_name
WHERE conditions_
ORDER BY column1_, column2_, .... ASC|DESC;
Explanation
Here, SELECT column1_, column2_……. is the command that tells the SQL server to select column1_, column2_,.... from table “table_name” fulfilling the conditions in WHERE clause.
Example
In this example, we will create a table and use the order by clause on the Score column with the DESC keyword.
SQL
SQL
CREATE TABLE Students ( ID INT PRIMARY KEY, Name VARCHAR(255), Score INT );
As the name suggests, the GROUP BY clause groups the rows with the same attribute values. It uses aggregate functions like SUM, AVG, MIN, MAX, and COUNT. Here, the tuples(rows) are grouped based on similarities between attribute values.
Group By Syntax
SELECT column_name1, function_type(column_name2)
FROM table_name
WHERE conditions_
GROUP BY column_name1
Explanation
Here, SELECT column_name1, function_type(column_name2) selects column_name and applies the aggregate function “function_type” on column_name2 from table “table_name” fulfilling the conditions in WHERE clause and finally grouping them by column_name1.
Example
In this example, we will create a table of orders and use the group by clause on the CustomerName column along with the SUM aggregate function.
Can the ORDER BY clause and the GROUP BY clause be used together in SQL?
Yes, but the placement of both clauses is vital. You must place the ORDER BY clause after the GROUP BY clause. And the GROUP BY clause must be placed after the WHERE clause.
What is the main difference between ORDER BY and GROUP BY clauses?
The ORDER BY clause sorts the data in ascending or descending order. Whereas the GROUP BY clause groups the tuples(rows) based on the similarities of columns. Using the aggregate function to use the GROUP BY clause is compulsory.
Is GROUP BY and ORDER BY same in SQL?
No, GROUP BY and ORDER BY are not the same. They serve different purposes. The GROUP BY clause is used to group rows that have the same values in one or more columns. On the other hand, the ORDER BY clause is used to sort the result set of a SQL query based on one or more columns.
Which is first GROUP BY or ORDER BY in SQL?
In SQL, the GROUP BY clause is executed before the ORDER BY clause. First, rows are grouped based on the specified columns in GROUP BY, and then the result set is sorted using ORDER BY.
Conclusion
In summary, both GROUP BY and ORDER BY are essential SQL clauses. GROUP BY helps organize data into groups, while ORDER BY sorts data based on specified columns. Understanding when to use each empowers efficient data management and querying in SQL.
In this article, we started by discussing what ORDER BY and GROUP BY clauses are. Then, we learned the syntax of these clauses and discussed them with examples. Finally, we discussed the key differences between these two clauses.