Category Archives for "Data Types and Functions"

Knowing which data types and functions to use ads flexibility to your query repertoire.  Each column in a table is defined by a data type, which in turn can server as an input to a function.

In this section is an archive of article covering the best data types and functions posts we have made.

If you’re looking for a good place to start, I would start with

Seven SQL Server Data Types you Must Know to get an understanding of to main types.

One you’ve done that, read

Built-In Functions (SQL Server) to get a good introduction to the various functions you can use to perform calculations, such as setting text to upper case, or determining the month from a date.

All the examples for this lesson are based on Microsoft SQL Server Management Studio and the sample databases AdventureWorks and WideWorldImporters.  You can get started using these free tools using my guide Getting Started Using SQL Server

Uncommon SQL Server Data Types

In this article we’re going to go over a uncommon SQL server data types.  These are those you won’t use every day, but you’ll want to know if you take the 70-461 exam. Even if you don’t plan on taking the 70-461, learning these data types is fun, especially the spatial datatype (I had no idea […]

Continue reading

Know when to use Cast versus Convert

In this article we’re going to explore the CAST and CONVERT functions to understand whether there are any significant differences worth knowing when we want to convert data from one type to another. Since CAST and CONVERT can be used interchangeably in most situations, you may be wondering if one is better than the other. […]

Continue reading

Learn to use SQL Server Date Functions

SQL server’s date functions provide you a set of function that you can use to manipulate dates.  The function are used for a wide variety of operation such as adding weeks to a date, calculating the difference between two dates, or to decompose a date into its fundamental parts. If you not familiar with SQL […]

Continue reading

Introduction to SQL Server’s Common String Functions

The built in SQL String functions make it possible for you to find and alter text values, such as VARCHAR and CHAR datatypes, in SQLServer.  Using these functions you can alter a text value such as changing “Smith, Joe” to “Joe Smith.” If you not familiar with SQL functions, then I would recommend staring with […]

Continue reading

Introduction to SQL Server’s Mathematical Functions

Mathematical Functions to Old Way - Slide Rule!

Math Rocks! SQLServer includes many mathematical functions you can use to perform business and engineering calculations.  Many of these aren’t used in typical day-to-day operations; however, there are several commonly used functions we’ll cover. If you not familiar with SQL functions, then I would recommend staring with the Introduction to SQL Server Built-In Functions. All […]

Continue reading

Introduction to SQL Server’s Built-In Logical Functions

Logical Circuit

Logical functions provide a way to use logical conditions to display one of several values.  You can use logical functions to test a field’s value such as gender (M or F) and display another value(‘Male’ or ‘Female’) as a result. In this article we describe how to use the CHOOSE and IIF functions.  CHOOSE is […]

Continue reading

Built-In Functions (SQL Server)

Built in SQL Functions

Built-In functions are used in SQL SELECT expressions to calculate values and manipulate data.  These functions can be used anywhere expressions are allowed.  Common uses of functions include to change a name to all upper case.  In this article we’ll introduce you to basic concepts. All the examples for this lesson are based on Microsoft […]

Continue reading

Converting Between Data Types with SQL Server Functions

SQL server uses data types to store a specific kind of value such as numbers, dates, or text in table columns and to use in functions, such as mathematical expressions. One issue with data types is that they don’t usually mix well.  Conversion functions make them mix better! Though there are time when types are […]

Continue reading

What is a Database NULL Value?

Null and unknown values

What is a Null Value? In databases a common issue is what value or placeholder do you use to represent a missing values.   In SQL, this is solved with null.  It is used to signify missing or unknown values.  The keyword NULL is used to indicate these values.  NULL really isn’t a specific value as much as it […]

Continue reading