Like most companies, yours probably relies on a database or two. If this sounds like your business, there’s a really good chance you’re leveraging SQL. This popular programming language was made specifically to help people manage data stored in a relational database management system (RDBMS). It also works for stream processing, though that would be for a relational data stream management system (RDSMS).
A Brief History of SQL
Structured Query Language was originally developed by Raymond F. Boyce and Donald D. Chamberlin while they were employees at IBM in the early 70s. Originally called SEQUEL (Structured English QUEry Language), it was a program created to manipulate and/or retrieve data found in IBM’s original relational database management system (known as System R).
Early on, Relational Software Inc. was convinced of the potential something like SQL could offer and developed their own RDBMS based on this programming language. At the end of 1979, Relational Software Inc. unveiled the first commercial version of it, called Oracle V2. IBM would soon follow, have tested their System R prototype across customer groups. One version actually came out in 1979 as well with two more following in 1981 and 1983.
SQL Today
Today, SQL is supported by most relational databases and is also monitored by the American National Standards Institute (ANSI). There is no one version, though (hence why it’s seen as a standard), as most major vendors have their own offering, including the likes of Oracle and Microsoft.
SQL remains one of the most popular methods for querying, inserting, updating and modifying data in a relational database. DBAs (Database Administrators) love SQL because it works with practically every relational database and across numerous platforms.
The Importance of Learning SQL
In fact, most DBAs consider it a rite of passage to learn it, culminating in the writing of one’s first script or SELECT statement without the help of GUI (Graphical User Interfaces).
If you’re familiar with relational databases, you might wonder why SQL is still around. Graphical tools also make it much easier to do queries. Anyone who’s ever used a drag-and-drop wizard knows that. The reason why SQL is still around, though, is because while those tools are convenient, they’re nowhere near as powerful.
The Four Types of SQL Code
You can divide this code into four categories:
- SELECT statements are used to handle queries. This category can be subdivided into WHERE, SELECT, FROM and ORDER BY.
- DML (Data Manipulation Language) is actually a subset of SELECT statements. It can be called upon to update, add or delete data and is made up of the DELETE, INSERT and UPDATE statements, plus other control statements like SAVEPOINT, BEGIN TRANSLATION, ROLLBACK and COMMIT.
- DDL (Data Definition Language) is utilized for managing index structures and tables. Examples of Data Definition Language statements include ALTER, DROP, CREATE and TRUNCATE.
- DCL (Data Control Language) is used to oversee the assigning and revoking of database rights and permissions. The two main statements it uses (though not the only ones) are GRANT and REVOKE.
While each of these four categories entails much more than just the above, this represents the main code SQL uses. This should also give you a better understanding of how helpful SQL can be for dealing with relational databases.
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Structured Query Language (SQL)
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