# DBNull

*noun*

say it: **“DEE-bee nul”** **/ˈdiːbiː nʌl/**

The value ADO.NET uses for a database NULL, which is not the same as C#'s null.

## What is **DBNull** in C#?

**DBNull** — The value ADO.NET hands you for a database `NULL`, as `DBNull.Value`. It isn't C#'s `null`, so check for it with `reader.IsDBNull(...)` before you read the column.

```csharp
int column = reader.GetOrdinal("Region");
string? region = reader.IsDBNull(column) ? null : reader.GetString(column);
```

## In a sentence

- “Reading the Region column threw an error until I checked for **DBNull** first.”

Level: Journeyman · [More C# terms at this level](https://www.ask-codey.com/glossary?category=c-sharp&level=3)

Updated: October 28, 2026

Source: https://www.ask-codey.com/glossary/dbnull