How to Avoid Unexpected 0s When Concatenating Strings in SQLite?

String Concatenation in SQLite: Bypassing the Null Coalescing Conundrum

In the realm of database management, the ability to concatenate strings is a fundamental operation. However, when working with SQLite, you may encounter a peculiar issue where the operator, typically used for string concatenation, does not seem to work as expected.

Consider the following SQLite query:

select locationname + '<p>' from location;

Instead of the anticipated string values with the specified text, you are greeted with a puzzling array of 0s. This peculiar behavior is not what you would expect from a string concatenation operation.

The key to unraveling this mystery lies in the nuances of SQLite's syntax. The operator in SQLite serves a dual purpose - it not only concatenates strings but also performs null coalescing. Null coalescing means that if any of the operands is NULL, the result will also be NULL.

In your specific query, if the locationname field contains NULL values, the operator will interpret these as 0s, resulting in the perplexing list of 0s. To circumvent this issue, SQLite provides an alternative operator specifically designed for string concatenation - the || operator.

The || operator, often referred to as the concatenation operator, is tailored to merge strings without any potential null coalescing. By utilizing this operator, you can achieve the desired string concatenation as intended.

select locationname || '<p>' from location;

In conclusion, when it comes to string concatenation in SQLite, remember to employ the appropriate operator for the task at hand. If null coalescing is not your intention, the || operator will prove to be your steadfast companion in the realm of string manipulations.

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