SQL Server Convert

Hello Dev, welcome to this journal article about SQL Server Convert. In this article, we will be discussing everything you need to know about converting data types in SQL Server. SQL Server Convert is a powerful tool that allows you to manipulate data types in your SQL Server database. This tool can help you convert data from one format to another, which is especially useful when working with different data sources. Let’s dive in!

What is SQL Server Convert?

SQL Server Convert is a built-in function in SQL Server that allows you to convert data from one data type to another. This function is useful when you need to change the data type of a specific field in your database, or when you need to convert data for comparison or sorting purposes.

Here’s a simple example of how SQL Server Convert works:

Original Data Type	Converted Data Type
Integer	Varchar
123	‘123’

In the above example, we are converting an integer value (123) to a varchar value (‘123’). This can be useful, for example, when you need to display the integer value as text in a report or on a web page.

How to Use SQL Server Convert

Using SQL Server Convert is simple. Here is the basic syntax:

CONVERT(target_data_type, expression, style)

The parameters are:

• target_data_type: the data type you want to convert to
• expression: the value you want to convert
• style: optional, specifies the format of the output

Let’s look at some examples to see how this works in practice.

SQL Server Convert Examples

Converting Dates

One common use case for SQL Server Convert is when working with dates. SQL Server stores dates as a datetime value, which includes both the date and time. However, you might need to convert this to a different format when working with the data.

For example, let’s say you have a table that contains a datetime field called dob. You want to display this on a web page in the format MM/DD/YYYY. Here’s how you can do that:

SELECT CONVERT(varchar, dob, 101) AS dob_formatted FROM my_table

The result will be a varchar value in the format MM/DD/YYYY.

There are many other date formats you can use with SQL Server Convert – see the table below for some examples.

Style	Output Format
100	mon dd yyyy hh:miAM (or PM)
101	mm/dd/yyyy
102	yyyy.mm.dd
103	dd/mm/yyyy

Converting Numbers

Another common use case for SQL Server Convert is when working with numbers. SQL Server stores numbers in a variety of formats, including integers, decimals, and floats. You might need to convert these to a different format for various reasons, such as display or calculation purposes.

Here are some examples of how you can use SQL Server Convert to convert numbers:

SELECT CONVERT(float, my_int_column) AS float_value FROM my_table

This will convert the integer value in my_int_column to a float value.

SELECT CONVERT(decimal(10,2), my_float_column) AS decimal_value FROM my_table

This will convert the float value in my_float_column to a decimal value with two decimal places.

SQL Server Convert FAQ

Can I convert data types without using SQL Server Convert?

Yes, there are other ways to convert data types in SQL Server, such as the CAST and CONVERT functions. However, SQL Server Convert is generally the most flexible and powerful option.

What happens if I try to convert data that is not compatible with the target data type?

If you try to convert data that is not compatible with the target data type, SQL Server will return an error. For example, if you try to convert a string value to an integer, but the string contains non-numeric characters, you will get an error.

What is the syntax for using SQL Server Convert with variables?

The syntax for using SQL Server Convert with variables is the same as with regular values:

SELECT CONVERT(target_data_type, @my_variable, style) AS converted_value FROM my_table

Can I use SQL Server Convert in a WHERE clause?

Yes, you can use SQL Server Convert in a WHERE clause to convert values for comparison purposes. For example:

SELECT * FROM my_table WHERE CONVERT(varchar, dob, 101) = '01/01/2000'

This will return all records where the dob field is on January 1st, 2000.

That’s it for this article. We hope you found it useful and informative. If you have any questions or comments, feel free to leave them below. Happy converting!