Understanding the ORA-00928 Error: Fixing the Missing SELECT Keyword in SQL Queries

Learn how to resolve the `ORA-00928` error by correctly using the SELECT keyword in SQL, with practical examples and best practices.
---

Visit these links for original content and any more details, such as alternate solutions, latest updates/developments on topic, comments, revision history etc. For example, the original title of the Question was: ORA-00928: missing SELECT keyword. Please explain

If anything seems off to you, please feel free to write me at vlogize [AT] gmail [DOT] com.
---
Understanding the ORA-00928 Error: Fixing the Missing SELECT Keyword in SQL Queries

When working with SQL, especially in Oracle databases, encountering errors can be a frustrating experience. One common error that developers face is the ORA-00928: missing SELECT keyword. This error signals a problem in your SQL syntax, typically pointing to a missing SELECT clause in a query. In this guide, we'll dissect this error, explore its causes, and guide you through the resolution with clear examples.

The Problem: Understanding the ORA-00928 Error

What Does ORA-00928 Mean?

The ORA-00928 error message indicates that there is a syntax issue in your SQL statement where the SQL engine expects a SELECT keyword but cannot find it. This frequently occurs within the context of creating views or writing complex SELECT statements.

Why Am I Getting This Error?

In the provided SQL code example, an attempt was made to create a view called norders. However, the error arises primarily because of an improper syntax. Here's the problematic code:

[[See Video to Reveal this Text or Code Snippet]]

In this code, the inclusion of N1 does not belong to SQL syntax, leading to the confusion and triggering the error.

The Solution: Correcting the SQL Syntax

Proper Syntax for Creating a View

To resolve the ORA-00928 error, you'll want to ensure that your SQL syntax is structured properly. Here's how to correctly create the view without errors:

[[See Video to Reveal this Text or Code Snippet]]

Breakdown of the Correct SQL Statement

CREATE VIEW Statement: This begins the process of creating a new view in the database.

AS Keyword: This clearly indicates that what follows is the definition of the view.

SELECT Statement: This is crucial and must always start with SELECT to retrieve data.

AVG and SUM Functions: These aggregate functions calculate the average and total purchases, respectively.

FROM Clause: The use of table aliases (s for Salesman and o for orders) enhances clarity.

JOIN: Instead of using commas to join tables, we should use the JOIN keyword. This is often considered better practice and improves readability.

GROUP BY Clause: This groups the results by the n_ame field so that aggregate calculations can be performed correctly.

Best Practices to Avoid Similar Errors

Always Use Explicit Joins: Instead of using commas to define a join between multiple tables, use explicit JOIN statements. This not only helps in preventing syntax errors but also enhances the clarity of the SQL query.

Double-check SQL Syntax: When encountering errors, revisit the SQL syntax to ensure keywords and clauses are properly placed.

Test Incrementally: If you're writing complex queries, build and test them in smaller sections to isolate any syntax issues.

Conclusion

The ORA-00928: missing SELECT keyword error can be frustrating, but understanding its cause and applying the right syntax can help you resolve it efficiently. By following best practices in SQL writing and ensuring proper syntax, you can avoid these kinds of errors in the future. Happy querying!