Basic SQL Tutorials
Introduction to SQL
The Structured Query Language (SQL) is the language of databases. All modern relational databases, including Access, FileMaker Pro, Microsoft SQL Server and Oracle use SQL as their basic building block. In fact, it’s often the only way that you can truly interact with the database itself.
The Structured Query Language provides the foundation for all relational database systems. Join us as we explore the fundamental concepts behind this powerful language.
Structured Query Language (SQL) Basics
Most large-scale databases use the Structured Query Language (SQL) to define all user and administrator interactions. This language offers a flexible interface for databases of all shapes and sizes.
Free Learning SQL E-Course
The Structured Query Language (SQL) forms the backbone of all relational databases. This language offers a flexible interface for databases of all shapes and sizes and is used as the basis for all user and administrator interactions with the database. In this course, you'll learn the basics of using SQL to store, retrieve and manipulate information in a database.
Retrieving Data with the SELECT Statement
The SELECT command is the most commonly used command in SQL. It allows database users to retrieve the specific information they desire from an operational database.
Inserting Data with the SQL INSERT Command
The INSERT command in SQL is used to add records to an existing table. Returning to the personal_info example from the previous section, let's imagine that our HR department needs to add a new employee to their database.
Creating Databases and Tables In SQL
Learn to create databases and tables using the Structured Query Language (SQL) in this step-by-step tutorial from your About.com Guide to Databases.
Deleting Database Tables with the DROP Command
The DROP command allows us to remove entire database objects from our database.
Access Controls in SQL
Our databases contain information that is vital to the continued operations of our organizations. In this article, your About.com Guide introduces the SQL commands used to control access to your database.
All About NULL Values
Users new to the world of databases are often confused by a special value particular to our field – the NULL value. Read about the proper uses of NULL in this article.
DISTINCT Keyword in SQL
The DISTINCT keyword in SQL allows you to select only those records that contain unique values for the columns requested in a SELECT statement. Duplicate values are ignored and only displayed once.
SQL INTERSECT Queries
SQL's INTERSECT operation allows you to identify the rows that appear in multiple source tables or SELECT query results. This set of common rows is known as the intersection of the two tables. The INTERSECT operation is related to the UNION operation that provides a listing of all of the rows that appear in any of the subject tables.