When working with the SQL Command Line Interface (CLI), it’s often useful to customize the output formatting to better suit your needs. By default, the CLI displays result sets in a tabular format, but sometimes you may want to modify the appearance or organization of the output.

In this article, we’ll explore some common techniques for customizing output formatting in the SQL CLI.

1. Changing Column Headers

By default, the CLI displays column headers based on the names of the selected columns in your SQL query. However, you may prefer to provide more descriptive or user-friendly names for the columns in your output.

To change the column headers, you can use the AS keyword in your SQL query to provide custom labels for each column. For example:

SELECT first_name AS 'First Name', last_name AS 'Last Name' FROM users;

This query renames the first_name and last_name columns as ‘First Name’ and ‘Last Name’, respectively. The CLI will display these custom labels as the column headers in the output.

2. Formatting Numeric Values

If your query contains numeric values, you can customize the formatting of these values to make them easier to read. For example, you might want to add thousands separators or specify the number of decimal places to display.

You can achieve this by using SQL’s built-in formatting functions, such as FORMAT or ROUND. Here’s an example:

SELECT product_name, FORMAT(price, 2) AS 'Formatted Price' FROM products;

In this query, the FORMAT function is used to round the price column to two decimal places. The CLI will display the formatted values in the output.

3. Controlling Query Output Size

By default, the CLI limits the number of rows displayed in the output of your query. This is useful for avoiding large result sets that may overwhelm the screen. However, if you want to view more rows or even unlimited rows, you can adjust the output size.

To change the output size, you can use the SET command along with the ROWLIMIT option. For example:

SET ROWLIMIT 1000;

This command sets the maximum number of rows displayed to 1000. You can replace 1000 with any desired value or use 0 for unlimited rows.

4. Exporting Query Results

If you need to save or transfer query results for further analysis or sharing, you can export the output to a file. The CLI provides the SPOOL command for this purpose.

To export the query result, you can use the following command:

SPOOL output.txt;
SELECT * FROM products;
SPOOL OFF;

This command saves the results of the SELECT statement to a file named output.txt in the current directory.

Conclusion

Customizing the output formatting in the SQL CLI can greatly enhance your experience and make it easier to work with the data. By changing column headers, formatting numeric values, controlling query output size, and exporting results, you can tailor the output to your specific needs.

With these techniques, you’ll have more control over the appearance and organization of the output, allowing you to efficiently analyze and share your SQL query results.

#SQL #CLI