An Important Consideration When Choosing Between LIST_CONCAT() and || For Concatenating Lists in DuckDB

When it comes to concatenating lists in DuckDB, we can use the list_concat() function (and its aliases), or the list concatenation operator (||). Often when we have a choice like this, we can use either option interchangeably. But that isn’t quite true in this case.

There’s an important difference between list_concat() and the || operator in DuckDB, and it all comes down to how it handles NULL values.

Continue reading

Understanding SQLite’s CAST() Expression

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.

Continue reading

Using the WHERE Clause Effectively: Common SQL Operators and Their Usage

The WHERE clause is a fundamental part of SQL queries that allows us to filter data based on specific conditions. Understanding how to use various operators within the WHERE clause can significantly enhance our ability to retrieve precisely the data we need.

This article explores some of the operators that are most commonly used with the WHERE clause.

Continue reading

Using the <@ Operator in PostgreSQL

In PostgreSQL, the <@ operator checks to see whether the second array contains the first array. That is, whether or not the array on the right of the operator contains all elements in the array to the left.

The function returns a Boolean result: It returns true if the second array contains the first array, and false if it doesn’t. If the result is unknown, it returns NULL.

Continue reading

How the @> Operator Works in PostgreSQL

In PostgreSQL, the @> operator checks to see whether the first array contains the second array. That is, whether or not the array on the left of the operator contains all elements in the array to the right.

The function returns a Boolean result: It returns true if the first array contains the second, and false if it doesn’t. If the result is unknown, it returns NULL.

Continue reading

A Quick Look at the && Operator in PostgreSQL

We can use the && operator in PostgreSQL to check two arrays for any overlapping elements.

We include an array on each side of the operator to compare them, and the result is a Boolean value that indicates whether or not there’s any overlap. A result of True (or t) indicates that there’s an overlap, while False (or f) indicates there’s no overlap.

Continue reading

Understanding the Right Shift and Left Shift Operators in SQL Server

SQL Server 2022 introduced a bunch of new bit manipulation functions and operators. Amongst these are the right shift and left shift operators.

The right shift and left shift operators can be used to shift bits to the left or right. Given an integer or binary expression, these operators can shift bits by the amount that we specify.

Continue reading