How to combine two columns in SQL

How to combine two columns in SQL

Using the concatenation operator (||)

To combine two columns in SQL, you can use the concatenation operator (||) to concatenate the values in the columns. Here is an example of how to do this:

SELECT first_name || ' ' || last_name AS full_name
FROM users

In this example, the SELECT statement is used to retrieve the values in the first_name and last_name columns from the users table.

The concatenation operator (||) is used to concatenate the values in these columns, with a space character (' ') added between the values to separate the first and last names. The resulting value is aliased as full_name and is returned by the query.

Using CONCAT function

Alternatively, you can use the CONCAT function to combine the values in the columns, like this:

SELECT CONCAT(first_name, ' ', last_name) AS full_name
FROM users

In this example, the CONCAT function is used to concatenate the values in the first_name and last_name columns, with a space character added between the values.

The resulting value is aliased as full_name and is returned by the query.

Conclusion

Both of these methods can be used to combine two columns in SQL.

The method you choose will depend on your specific requirements and the database management system you are using. Some database management systems may not support the concatenation operator (||), in which case you can use the CONCAT function instead.