Database Management Systems
If you’re getting an error that reads something like “No function matches the given name and argument types ‘bool_and(INTEGER)’” in DuckDB, it’s probably because you’re passing a non-boolean value to the bool_and() function.
The bool_and() function is for use against boolean expressions, so to fix this issue, be sure that the argument you pass to the function is a boolean expression.
The favg() function in DuckDB calculates averages using a floating point summation method known as Kahan summation (or compensated summation). This method helps reduce the accumulation of rounding errors that can occur when many floating point numbers are involved when using the regular avg() function.
In DuckDB, avg() is an aggregate function that returns the average of all non-NULL values in its argument (usually a column).
In this article we’ll take a quick look at this function, along with some basic examples.
Continue readingDuckDB is a high-performance, in-process SQL database management system that supports various modes of operation, including the ability to create an in-memory database. An in-memory database stores all data in RAM, ensuring fast access and excellent performance.
This article explores how to create an in-memory database in DuckDB.
Continue readingSQLite is a lightweight, self-contained database engine renowned for its simplicity and flexibility. One of its unique features is the way it handles data types through type affinity, which determines how SQLite associates values with storage classes.
Unlike many database systems that enforce strict type constraints, SQLite’s type affinity system is more flexible, accommodating a broader range of data.
Continue readingIn DuckDB, arg_min() is an aggregate function that finds the row with the minimum value in one column and returns the corresponding value from another column at that row. Rows where either of the first two expressions is NULL are ignored.
In this article we explore DuckDB’s arg_min() function with some simple examples.
In DuckDB, arg_max() is an aggregate function that finds the row with the maximum value in one column and returns the corresponding value from another column at that row. Rows where either of the first two arguments is NULL are ignored.
Let’s take a look at the arg_max() with some straightforward examples.
In SQLite, the pow() function calculates the result of raising one number to the power of another. In other words, it performs an exponentiation operation.
The pow() function is particularly useful for mathematical operations where powers or exponents are required.
It’s also available as power(). Both syntaxes do the same thing.
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 reading