Group by Clause in oracle DBMS

[Laquan]

Hello & good Morning to all !!

I am unable to know the concept of Group by clause. I need your help to know about this concept. I will be very thankful to know about this. The problem is that, I have a query to access the counts of certain data from a table,I need to display two of the values and the others I would like to group them.

Thanks.

[Praetor]

Group by Clause :

The Group by Clause is being used to make the group of one or more than one columns which will produce the results in a sorted order of GROUP BY columns.

It is actually used to get data form the table in a sorted form.But it is always recommended to use the ORDER BY clause with the GROUP BY when ever the sorting is required.

[Katty]

Syntax Group by Clause :

You can implement the GROUP BY clause whenever you requires the sorting of data and you can implement it like this way using syntax :

SQL> SELECT <column_name>, <aggregating_operation>
FROM <table_name>
GROUP BY <column_name>;

Using this syntax,you can implement it with the required statement to access the sorted data from database objects.

[kelfro]

Implementing Group by Clause :

You can implement the GROUP BY clause with the statement when you need to use.I am going to show you an example which will show how to implement :

SELECT dept_id, dept_owner, SUM(sales) as "Total sales"
FROM order_details
GROUP BY dept_id, dept_owner
ORDER BY dept_id;

In the above example,two columns are being used to sort the required data with the GROUP BY clause.

[Zecho]

ORDER BY Clause :

The ORDER BY clause is being used to sort the records in your result set.It is used only with SELECT statements.To view the syntax of the ORDER BY clause is given below :

SELECT <column_name,....>
FROM <table_name>
WHERE (...predicates...)
ORDER BY column ASC/DESC;

[Reegan]

ASC and DESC with ORDER BY Clause :

The ASC and DESC option specifies the type of sorting. The column which is added with ORDER BY clause.These options are used to make a set of order of those values which reside in the columns.

The ASC sorts the values in Ascending order and DESC sorts in descending order.If you omit this option with Order clause then the ASC will take place as default option.