SQL CREATE UNION: Combine Data from Multiple Tables

An Introduction to SQL CREATE UNION

In SQL, the CREATE UNION statement is used to combine data from two or more tables into a single result set. Whether you are a beginner or an experienced SQL user, understanding how to use CREATE UNION can greatly enhance your ability to manipulate and analyze data effectively.

How Does SQL CREATE UNION Work?

The CREATE UNION statement allows you to merge the result sets of two or more SELECT queries. It combines the rows from each query's result set and removes any duplicate rows, resulting in a single result set.

To use CREATE UNION, the SELECT queries must have the same number of columns, and the corresponding columns must have compatible data types. The columns in the result set will have the same names as the columns in the first SELECT query.

Example Usage of SQL CREATE UNION

Let's say we have two tables in a database: "Customers" and "Suppliers". Both tables have columns for "ID", "Name", and "City". We can use CREATE UNION to combine the data from these tables into a single result set:

    
      SELECT ID, Name, City
      FROM Customers
      UNION
      SELECT ID, Name, City
      FROM Suppliers;
    
  

In this example, the result set will contain unique combinations of ID, Name, and City from both the "Customers" and "Suppliers" tables.

Benefits of Using SQL CREATE UNION

The CREATE UNION statement provides several benefits:

• Combine data from multiple tables: CREATE UNION allows you to easily merge the information from different tables, simplifying data analysis and reporting.
• Remove duplicate rows: The UNION operation automatically removes duplicate rows from the result set, saving you time and effort.
• Flexible querying: You can apply filtering conditions, sorting, and other SQL operations to the combined result set, providing powerful data manipulation capabilities.

Conclusion

SQL CREATE UNION is a valuable tool for combining data from multiple tables in a single result set. By using CREATE UNION, you can streamline your data analysis processes and gain deeper insights from your database. Whether you're working with large datasets or need to perform complex queries, understanding how to effectively use CREATE UNION will greatly enhance your SQL skills.

Thank you for reading this article. We hope that it has provided you with a clear understanding of SQL CREATE UNION and its benefits in data manipulation. By utilizing CREATE UNION, you can unlock the full potential of your SQL queries and make more informed decisions based on your data.