SQL 101 Tag Archives

What is the difference between a primary and unique key?

Primary and Unique Key

In this article we learn the difference between a primary and unique key, and why both are important to maintaining a relational database structure. All the examples for this lesson are based on Microsoft SQL Server Management Studio and the AdventureWorks2012 database.  You can get started using these free tools using my Guide Getting Started Using SQL […]

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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 […]

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What is the difference between WHERE and HAVING clauses?

In this article learn when to use WHERE and HAVING.  Both perform similar functions, but for different purposes! All the examples for this article are based on Microsoft SQL Server Management Studio and the AdventureWorks2012 database.  You can get started using these free tools using my Guide Getting Started Using SQL Server. How do Where and Having Differ? […]

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Do Partial Matches Using LIKE

Pattern Matching with LIKE

In this lesson you are going to explore how to do pattern matching with the SQL Where clause LIKE operator.  Using this phrase allows us perform partial matches of data values and obtain answers to questions which can’t be done with conventional comparisons. The lesson’s objectives are to: learn about the like clause understand wild cards […]

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What are the Top Ten Databases?

Everyone has their favorite DBMS, is your favorite one of the top databases? Though some non-relational products have entered the top ten, the relational paradigm remains firmly entrenched in the database world.  However specialized database types such document store databases and wide column stores are gaining in popularity to become top databases. Top of the […]

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Query Results Using Boolean Logic

Old Fashioned Computer

In today’s lesson you’re going to learn how to query results using the WHERE clause. The objectives of today’s lesson are to: Learn to use more than one compare condition at a time using Boolean logic Comprehensive example with Select, Where, and Order By Using Multiple Conditions to Query Results In previous lesson’s we learned how the […]

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How to Filter Query Results

Where Clause

In today’s lesson you’re going to learn how filter the results returned from your queries using the WHERE clause.  This clause is important as only those records matching the where clause’s conditions are returned in the query results. The objectives of today’s lesson are to: Learn about various condition types, such as Equality, Range, and […]

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How to Filter Query Results

In today’s lesson you’re going to learn how to filter query results using the WHERE clause.  This clause is important as only those records matching the where clause’s conditions are returned in the query results. The objectives of today’s lesson are to: Learn about various condition types, such as Equality, Range, and Membership Comprehensive example […]

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How to sort results using SQLite

Order

In this lesson you are going to explore how to sort your query results by using SQL’s ORDER BY statement.  Using this phrase allows us to sort our result in ascending or descending order.  In addition you can limit your query to a specified number of results. The lesson’s objectives are to: learn how to […]

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