Home >> FAQs/Tutorials >> Oracle Tutorials
Oracle Tutorials - Understanding SQL SELECT Query Statements
A collection of 33 FAQs on Oracle SQL SELECT query statements. Clear answers are provided with tutorial exercises on selecting rows and columns from tables and views, sorting and counting query outputs, grouping outputs and applying group functions, joining tables, using subqueries.
Topics included in this FAQ are:
- What Is a SELECT Query Statement?
- How To Select All Columns of All Rows from a Table?
- How To Select Some Columns from a Table?
- How To Select Some Rows from a Table?
- How To Sort the Query Output?
- Can the Query Output Be Sorted by Multiple Columns?
- How To Sort Query Output in Descending Order?
- How To Use SELECT Statement to Count the Number of Rows?
- Can SELECT Statements Be Used on Views?
- How To Filter Out Duplications in Returning Rows?
- What Are Group Functions?
- How To Use Group Functions in the SELECT Clause?
- Can Group Functions Be Mixed with Non-group Selection Fields?
- How To Divide Query Output into Groups?
- How To Apply Filtering Criteria at Group Level?
- How To Count Duplicated Values in a Column?
- Can Multiple Columns Be Used in GROUP BY?
- Can Group Functions Be Used in the ORDER BY Clause?
- How To Join Two Tables in a Single Query?
- How To Write a Query with an Inner Join?
- How To Define and Use Table Alias Names?
- How To Write a Query with a Left Outer Join?
- How To Write a Query with a Right Outer Join?
- How To Write a Query with a Full Outer Join?
- How To Write an Inner Join with the WHERE Clause?
- How To Write a Left Outer Join with the WHERE Clause?
- How To Name Query Output Columns?
- What Is a Subquery?
- How To Use Subqueries with the IN Operator?
- How To Use Subqueries with the EXISTS Operator?
- How To Use Subqueries in the FROM Clause?
- How To Count Groups Returned with the GROUP BY Clause?
- How To Return Top 5 Rows?
Sample scripts used in this FAQ assumes that you are connected to the server with the HR user account
on the default database instance XE. See other FAQ collections on how to connect to the server.
Some sample scripts may require database tables created by other samples in the beginning of the collection.
(Continued on next topic...)