When using DuckDB’s command line interface (CLI), we can use the .mode command to change how query results are formatted. For example, we can output query results as a table, in CSV format, or even JSON. Another option is to output it in “line” mode, which outputs the query results vertically, as opposed to horizontally across the screen.
This article demonstrates how to enable vertical query output in the DuckDB CLI with line mode.
In DuckDB, the CONCAT_WS() function provides an efficient way to join strings with a specified separator. CONCAT_WS() stands for “concatenate with separator”, and many RDBMSs have such a function.
CONCAT_WS() is particularly useful when you need to combine multiple fields or values with a consistent delimiter.
Let’s explore its features and practical applications.
Continue readingString concatenation is a common operation in database queries, and many database management systems (DBMSs) provide at least one or two ways to concatenate strings. DuckDB is no exception.
One option for concatenating strings in DuckDB is with the CONCAT() function. This function provides a robust and NULL-safe way to combine strings.
Unlike the concatenation operator (||), CONCAT() handles NULL values gracefully and provides a cleaner syntax for combining multiple strings.
In this article, we’ll explore everything from basic usage to advanced techniques and best practices.
Continue readingPartial indexing is a feature in many DBMSs, including SQLite, that allows developers to optimize database performance by creating indexes only for specific subsets of data. This can significantly reduce the index size and improve query speed, especially in cases where only a portion of the data is frequently queried.
In this article, we’ll look at how to create a partial index in SQLite, why it’s useful, and provide an example to illustrate its use.
Continue readingDuckDB is a fast and reliable analytical database that offers a bunch of aggregate functions. One such function is ANY_VALUE().
In this post, we’ll explore the ANY_VALUE() function, along with examples to demonstrate its usage.
The FLOOR() function in SQLite returns the largest integer value that is less than or equal to a given numeric expression. Essentially, it “rounds down” a decimal number to the nearest integer below it.
This function is useful in cases where you want to discard the decimal portion of a number without rounding up.
Continue readingIf you’re getting an error that reads “mode should be one of: ascii box column …etc” in DuckDB, it appears that you’re trying to set the output mode to an invalid value.
While we can change the output mode in DuckDB, it must be one of the supported modes.
To fix this issue, be sure to use a supported mode.
Continue readingDuckDB’s CLI provides a convenient way to generate INSERT statements from query results. This can be particularly useful for data migration, creating test data, or backing up specific data subsets. Here’s how to do it.
SQLite is a widely-used lightweight database engine that powers many mobile, embedded, and desktop applications. One of its key features is its dynamic type system, which allows flexibility in handling data. While this is advantageous in many scenarios, there are cases where developers need precise control over how data is treated or converted between types. This is where SQLite’s CAST() expression comes in.
NULL values in databases can be tricky to handle and often lead to unexpected results. DuckDB’s COALESCE() function provides an easy way to manage NULL values effectively.
In this article, we’ll explore the COALESCE() function in DuckDB with some practical examples.