SQL Server gives you two functions for formatting values: FORMAT() and CONVERT(). They overlap enough that it’s not always obvious which one to reach for. This article skips the feature-by-feature breakdown and focuses on answering the question of which one you should use for a given scenario.
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SQL Server CONVERT() Date Style Codes Explained (With Examples)
In SQL Server, dates are stored in one format but often need to be displayed in another. That’s where the CONVERT() function can help. It lets you take a date value and turn it into a string in whatever format you need, whether that’s MM/DD/YYYY for an American audience or DD-MM-YYYY for a universally recognized date format.
The tricky part when using this function is the style code. This a number you pass into CONVERT() that tells it which format to use. There are dozens of style codes, and they’re not exactly intuitive to memorise. This article breaks down the most useful ones with real examples so you can find what you need and move on.
How to Convert a Date to a String in SQL Server
There are a few reasons you might need to convert a date to a string in SQL Server. Maybe you need a date in a specific format for a report. Maybe you’re concatenating it with other text. Maybe an external system expects dates as strings. Whatever the reason, SQL Server gives you several ways to do it, and the right one depends on what you’re trying to achieve.
This article covers four functions: FORMAT(), CONVERT(), CAST(), and STR().
How to Format Dates in SQL Server (A Beginner’s Guide)
Dates in SQL Server can be surprisingly tricky if you’re new to the game. The way dates are stored is not always the way you want them displayed, and figuring out how to convert one to the other is one of those things every beginner eventually Googles. So let’s walk through it clearly.
How to Convert JSON to Rows and Columns in SQL Server
Modern applications often exchange information in JSON, and that data often ends up in SQL Server. While JSON’s flexible structure makes it ideal for storing dynamic or nested data, it doesn’t fit neatly into traditional relational tables. The good news is that SQL Server includes a good selection of JSON functions that let you parse, query, and transform JSON content into structured rows and columns. This means that you can work with your JSON data just like any other table.
Using CAST() to Convert Rounded Values to Integers in SQL Server
Sometimes when you’re working with calculated columns in SQL Server, you might get results in a data type that’s less than ideal. For example, maybe it’s a decimal or float when you really need an integer. This can result in the output not appearing exactly the way you want, such as with a bunch of unnecessary trailing decimal zeros.
In such cases, you’ll probably want to remove these trailing zeros from the result. The CAST() function is perfect for this kind of cleanup. You can use it to convert the value to a more suitable type.
When to Use TRY_CONVERT() vs CONVERT() in SQL Server
Both CONVERT() and TRY_CONVERT() in SQL Server are used to convert data types, but they behave quite differently when something goes wrong. Understanding that difference can save you a lot of debugging time, especially when dealing with messy or unpredictable data.
Let’s look at when you should use each, and walk through an example that you can run yourself.
5 Ways to Convert DD/MM/YYYY to DATE in SQL Server
Converting a string in DD/MM/YYYY format to a DATE type can be done in several ways in SQL Server. This article presents five options along with examples.
Handling International Date Formats When Casting to DATETIME in SQL Server
Working with dates in SQL Server is usually quite straightforward. There’s a good range of date types and functions that we can use to manipulate date/time values.
But international date formats can undo all that simplicity in a heartbeat. Something as simple as casting a string into a DATETIME type can blow up depending on how the server interprets the input. This often happens when you’re dealing with applications or imports that don’t stick to a single culture or regional setting.
Let’s walk through an example and see why SQL Server behaves this way, and more importantly, how to handle it correctly.
Fixing Invalid Date Conversions in SQL Server
When you work with dates in SQL Server, you’ll often run into situations where a value can’t be converted directly to a datetime or date. This usually happens because the source data isn’t in a format SQL Server recognises, or because the value itself is out‑of‑range (e.g., “2025‑02‑30”). Fortunately, the built‑in conversion functions CAST() and CONVERT() provide us with enough flexibility to clean up those problematic values without resorting to messy string manipulation.
Below we’ll look at the most common scenarios, show how to diagnose the issue, and demonstrate how to fix it.