Use Multiple Columns in GROUP BY in Oracle

Q

Can Multiple Columns Be Used in GROUP BY in Oracle?

✍: FYIcenter.com

A

You can use multiple columns in the GROUP BY clause as shown in the following example. It returns how many employees are having the same salary in each department:

SQL> SELECT department_id, salary, count(*) 
  2  FROM employees GROUP BY department_id,
  3  salary HAVING count(*) > 1;
DEPARTMENT_ID     SALARY   COUNT(*)
------------- ---------- ----------
           90      17000          2
           50       3200          4
           50       2200          2
           50       3600          2
           80      10500          2
           80       9000          2
           50       2700          2
......

⇒ Use Group Functions in ORDER BY Clause in Oracle

⇐ Count Duplicated Values in a Column in Oracle

⇑ Understanding SQL SELECT Query Statements in Oracle

⇑⇑ Oracle Database Tutorials

2019-10-27, 4618🔥, 0💬

Divide Query Output into Groups in Oracle
How To Divide Query Output into Groups in Oracle? You can divide query output into multiple groups with the GROUP BY clause. It allows you specify a column as the grouping criteria, so that rows with the same value in the column will be considered as a single group. When the GROUP BY clause is speci... 2019-11-21, 3724🔥, 0💬

Query with an Inner Join in Oracle
How To Write a Query with an Inner Join in Oracle? If you want to query from two tables with an inner join, you can use the INNER JOIN ... ON clause in the FROM clause. The following query returns output with an inner join from two tables: employees and departments. The join condition is that the de... 2019-10-27, 3556🔥, 0💬

Query with a Left Outer Join in Oracle
How To Write a Query with a Left Outer Join in Oracle? If you want to query from two tables with a left outer join, you can use the LEFT OUTER JOIN ... ON clause in the FROM clause. The following query returns output with a left outer join from two tables: departments and employees. The join conditi... 2019-10-18, 3494🔥, 0💬

Group Functions Used with Non-group Selection Fields in Oracle
Can Group Functions Be Mixed with Non-group Selection Fields in Oracle? If a group function is used in the SELECT clause, all other selection fields must be group level fields. Non-group fields can not be mixed with group fields in the SELECT clause. The script below gives you an example of invalid ... 2019-11-21, 3436🔥, 0💬

Define and Use Table Alias Names in Oracle
How To Define and Use Table Alias Names in Oracle? When column names need to be prefixed with table names, you can define table alias name and use them to prefix column names as shown in the following select statement: SQL> SELECT e.first_name, e.last_name, d.department_name FROM employees e ... 2019-10-27, 3436🔥, 0💬

Apply Filtering Criteria at Group Level in Oracle
How To Apply Filtering Criteria at Group Level in Oracle? If you want to return only specific groups from the query, you can apply filtering criteria at the group level by using the HAVING clause inside the GROUP BY clause. The following script gives you a good HAVING example: SQL> SELECT dep... 2019-11-21, 3287🔥, 0💬

Use Group Functions in ORDER BY Clause in Oracle
Can Group Functions Be Used in the ORDER BY Clause in Oracle? If the query output is aggregated as groups, you can sort the groups by using group functions in the ORDER BY clause. The following statement returns how many employees are having the same salary in each department. The group output is so... 2019-10-27, 3230🔥, 0💬

Ways to Join Two Tables in a Single Query in Oracle
How To Join Two Tables in a Single Query in Oracle? Two tables can be joined together in a query in 4 ways: Inner Join: Returns only rows from both tables that satisfy the join condition. Left Outer Join: Returns rows from both tables that satisfy the join condition, and the rest of rows from the fi... 2019-10-27, 3090🔥, 0💬

Use Group Functions in the SELECT Clause in Oracle
How To Use Group Functions in the SELECT Clause in Oracle? If group functions are used in the SELECT clause, they will be used on the rows that meet the query selection criteria, the output of group functions will be returned as output of the query. The following select statement returns 4 values ca... 2019-11-21, 3087🔥, 0💬

All rights in the contents of this web site are reserved by the individual author. fyicenter.com does not guarantee the truthfulness, accuracy, or reliability of any contents.