When working with SQLite, displaying query results in a customized format can significantly improve readability and data parsing. The .separator dot command provides a powerful way to define specific delimiters for both columns and rows in your output. This guide will walk you through how to effectively use this command to tailor your SQLite output.

Understanding the .separator Command

The .separator command takes two arguments:
1. Column Separator: The string used to separate individual columns within a row.
2. Row Separator: The string used to separate different rows in the result set.

By default, the row separator is a newline character ( or on Windows), and the column separator varies based on the output mode.

Basic Usage with Custom Separators

Let’s say you want to separate columns with a pipe (|) and rows with a series of dashes (---). You would use the command as follows:

.separator "|" "---"

This would produce output where each column is delimited by | and each complete row is followed by ---. For example:

1|The Hobbit|J.R.R. Tolkien|310|1937-09-21|39.99---2|The Fellowship of the Ring|J.R.R. Tolkien|423|1954-07-29|49.99---

Incorporating Newlines for Enhanced Readability

Often, you’ll want the row separator to appear on a new line for better visual separation. You can embed newline characters () directly into your separator string. For instance, to have each row followed by a newline and then ---, you’d use:

.separator "|" "
---"

This will produce output like:

sqlite> .separator "|" "
---"
sqlite> select * from books;
1|The Hobbit|J.R.R. Tolkien|310|1937-09-21|39.99
---2|The Fellowship of the Ring|J.R.R. Tolkien|423|1954-07-29|49.99
---3|The Two Towers|J.R.R. Tolkien|352|1954-11-11|49.99
---4|The Return of the King|J.R.R. Tolkien|416|1955-10-20|49.99
---sqlite>

Notice that the --- appears after each row. Other special characters like (carriage return) or (tab) can also be used in both column and row separators.

Output Modes and Separator Settings

It’s important to understand which output modes respect the .separator command. Currently, the primary modes that utilize these custom settings are:

• list: Default mode, where columns are separated by | by default.
• quote: Similar to list, but values are quoted.

For other modes like tabs or csv, you might need a slightly different approach if you only want to change the row separator while keeping the default column separator for that mode.

Maintaining Default Column Separators in Specific Modes

If you’re in tabs mode and want to keep the column separator as a tab () but change the row separator, you must explicitly set the column separator to along with your desired row separator. For example, to use a double newline (`

) as a row separator intabs` mode:

.mode tabs
.separator "    " "

"

This will ensure your columns remain tab-separated while each record is followed by two newlines, creating a blank line between rows:

sqlite> .mode tabs
sqlite> .separator "    " "

"
sqlite> select * from books;
id      title   author  pages   release_date    price

1       The Hobbit      J.R.R. Tolkien  310     1937-09-21      39.99

2       The Fellowship of the Ring      J.R.R. Tolkien  423     1954-07-29      49.99

3       The Two Towers  J.R.R. Tolkien  352     1954-11-11      49.99

4       The Return of the King  416     1955-10-20      49.99

sqlite>

Similarly, for csv mode, you would set the column separator to a comma (,) if you wish to maintain its default while modifying the row separator.

Conclusion

The .separator dot command is an invaluable tool for anyone needing precise control over SQLite’s output formatting. By understanding its arguments and how it interacts with different output modes, you can generate highly structured and readable data for various purposes, from scripting to custom data exports. Experiment with different separators to find the format that best suits your needs.