Database Management Systems
In DuckDB, we can use functions like strftime() and strptime() to format date or timestamp values. These functions accept a format string that specifies how the date or timestamp should be formatted.
The format string consists of one or more format specifiers. For example, '%d/%m/%Y' is a format string that consists of three format specifiers. The output from that format specifier might look something like 05/09/2050.
DuckDB has a min_by() function that’s similar to the min() function, but with a twist. While the min() function simply returns the minimum value, the min_by() function finds the row with the minimum value in one column and returns the corresponding value from another column at that row.
Here are some examples that demonstrate how it works.
Continue readingIf you find yourself running a lot of ad-hoc queries that start with SELECT * FROM, you might be interested in this interesting feature of DuckDB.
DuckDB allows us to start queries with the FROM clause. When we do this, DuckDB will return all columns without us needing to specify SELECT *.
One common operation you may find yourself doing occasionally in DuckDB is adding intervals to date and/or time values. DuckDB provides us with a couple of easy ways to do this.
Here are two ways to add days to a date in DuckDB.
Continue readingIn SQL databases, COUNT() is a commonly used aggregation function that returns the number of rows in a group. In this article, I run some examples of the COUNT() function in DuckDB. DuckDB is a high-performance analytical database system that’s designed to be fast, reliable, portable, and easy to use.
If you’re getting an error that reads “Binder Error: RESERVOIR_QUANTILE can only take parameters in the range [0, 1]” in DuckDB, it appears that you’re passing an invalid second argument to the reservoir_quantile() function.
To fix this issue, make sure the second argument is between 0 and 1.
Continue readingDuckDB includes a reservoir_quantile() function that allows us to compute approximate quantiles efficiently. It provides the approximate quantile using reservoir sampling. This function can be handy when working with large datasets where exact quantile computation would be too slow or resource-intensive.
In this article, we will explore how the reservoir_quantile() function works, along with examples to demonstrate its usage.
DuckDB has a date_add() function, which allows us to add a specified time interval to a date or timestamp. This article looks at how the date_add() function works in DuckDB, including its syntax, usage, and examples.
DuckDB is an in-process SQL OLAP database management system designed for analytical workloads. It is known for its speed, efficiency, and ease of use. One of the many functions DuckDB provides is current_date, which is useful for working with date-related data.
In this article, we’ll look at how the current_date function works, along with some straightforward examples.
SQLite is a lightweight, serverless SQL database engine commonly used for developing mobile applications, web applications, and embedded systems. Among its various functionalities, SQLite allows developers to create indexes, including unique indexes, to enhance data retrieval speed and enforce constraints on data integrity.
A unique index ensures that all values in a specific column, or combination of columns, are distinct, preventing duplicate entries.
In this guide, we’ll walk through the basics of unique indexes in SQLite, explore when and why to use them, and provide examples of how to create them.
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