Essential SQL

Introduction Database normalization is process used to organize a database into tables and columns.  The idea is that a table should be about a spec [...]

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 part [...]

What is a Stored Procedure? A stored procedure is a group of one or more database statements stored in the database’s data dictionary and called fr [...]

In this post I interview Eugenio Tacchini, author of DaDaBIK and college professor, and ask him what he feels beginning SQL students should learn and [...]

[...] . Here is a list of all the employees.  To keep it simple only the LastName is shown. In the sample database you could write the following statement to get these results: And here are the Orders. You [...]

[...] we consider combining more than one field to filter a result.  For instance, using our sample database as an example, we may want to find large orders, such as those with a quantity greater than [...]

[...] Getting Started with SQL Server.  You get instructions on how to install the free tools and sample database. Using Multiple Conditions In previous lesson’s we learned how the where clause is used [...]

[...] just add an ORDER BY clause as Exercises It’s important to practice! Use the sample database to answer these questions. Select OrderID, OrderDate, and FreightCharge for all Orders whose [...]

[...] such, SQLite has become very popular with smart phone developers. Learn SQL with SQLite There are several reasons I feel that SQLite3 is suitable for beginners. The first [...]

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 [...]

In today’s lesson you’re going to learn about grouping results returned from your queries using the GROUP BY clause. The objectives of to [...]

When working with SQL databases it is often useful to create diagrams of the database tables and their relationships.  These may be done during t [...]

[...] thing you want in this window, as it is basically a text editor.  Cut and paste or type in a SQL statement, then click Execute to run the statement. The results are show in the bottom portion of the [...]

[...] of last name, those whose last names start with C. With this requirement in mind, our SQL statement becomes: Notice the join condition remains the same.  The only changes are the addition [...]

[...] a value.  As you may expect, the equals sign is used to form an equality.  It the following SQL statement were returning all Persons whose title is Mr. Other examples of equality conditions include: [...]

[...] are grouped, only the unique combinations are returned. The GROUP BY Clause is added to the SQL Statement after the WHERE Clause.  Here is an example where we are listing SalesOrderID, excluding [...]

What is a Null Value? In databases a null value is used to represent a value is unknown.  It is used to signify missing or unknown values.  The [...]

Outer Joins The series starts with the article Introduction to Database Joins.  All the examples for this lesson are based on Microsoft SQL Server [...]

All the examples for this lesson are based on Microsoft SQL Server Management Studio and the AdventureWorks2012 database.  You can get started using [...]

All the examples for this lesson are based on Microsoft SQL Server Management Studio and the AdventureWorks2012 database.  You can get started using [...]