Database administrators – or those that handle the administrative tasks associated with running a database system, rely on a database programming language to issue queries to retrieve and manipulate data from their respective database. Database programmers, data analysts, data modelers, and anyone who needs to access the information stored in a relational database management system (RDBMS) use some form of what is known as SQL – or Structured Query Language. In this database development tutorial, we discuss what SQL is, its benefits, and disadvantages.
Before we begin learning about SQL, a quick question: do you prefer to learn in a classroom or online course setting? If so, we have a tutorial highlighting the Best Online Courses to Learn SQL that can help you get started down the right path.
Overview of Structure Query Language
Structured Query Language (SQL) is a programming language used to issue commands to a database system for purposes of database management, adding information, manipulating data, or for the retrieval of data from a table. SQL, in particular, is the standard language used by database administrators and database programmers to interact with relational database management systems, which include:
- IBM DB2
- Microsoft Access
- MS SQL Server
It should be noted that many of the above RDBMS have their own version or flavor of SQL that are proprietary to each database environment. That being said, they do share much of the same syntax and statements that standard SQL does, including statements like:
What Is SQL Used For?
SQL is a powerful database programming language and a standard of both the American National Standards Institute (ANSI) and the International Organization for Standardization. Primarily, the language is used to manipulate the data in a relational database in some fashion, which can include, but is not limited to, the following:
- You can use SQL to execute queries against a database or tables within a database
- You can use SQL to retrieve information from a database or tables within a database
- You can use SQL to manipulate information in a database. This can include adding records, updating records, and deleting records from a table.
- You can use SQL to manipulate database structures in general; a database admin or database programmer can create new databases, create new tables, edit existing table structures (such as adding new columns), form relationships, create stored procedures, and create views and reports.
- You can use SQL to manage database users, set permissions, perform security related tasks, and backup/restore information stored in a database or its tables
What is a Relational Database Management Systems? (RDBMS)
A relational database system – also known as a RDBMS – is a database system that is based on relationships between data points in a table structure, which is made up of columns, rows, and individual cells. Rows run horizontal in a relational database, while columns run vertically. Each row consist of one or more cells, dependent upon how many columns exist. For example, consider a database table that contains the names of customers and their phone numbers. In such a database, each row would contain a cell for first name, last name, and phone number. Each of these cells would be related to one another, because they are within the same row. Each of these data points, further, would correspond to a column, which would represent each data point type.
Any data point or cell under the First Name column would be equated to a person’s first name. Likewise, any cell under the Last Name column would be considered a person’s last name, and so forth.
In addition, tables within a relational database system can also be related and the data within individual tables can be related to one another. Building upon our table of names and phone numbers, we might also have a table full of social security numbers. A database administrator could then create a relationship between the First Name, Last Name, and Social Security data so that the information would be related and considered part of the same row (essentially, if not in reality), without the data having to reside within the same table.
The reason for this separation of data into separate tables can be plentiful. Sometimes data is kept in table for security and data integrity reasons; other times, new data points might be added after a table structure has been created, and it becomes easier to store the new information in a separate table.
What are the Benefits of SQL?
There are many benefits of using SQL for database administrators and database programmers. These include the following:
- Data queries are processed faster. Information can be retrieved from tables rapidly and operations performed on data are also carried out quickly. These include deletions, insertions, and any other sort of data manipulation, updates, or changes.
- SQL is a simply language and has a simple syntax. While SQL does have a large number of statements, the language is not as complex or large as regular programming languages. This makes it easy to use, learn, understand, and reference.
- SQL is highly portable, meaning it works on many different types of operating systems, architectures, coding environments, server environments, embedded systems (such as those use in the Internet of Things or IoT), and so forth.
- The database programming language is extremely popular, and, as such, support is simple to find for SQL statements, functions, queries, and syntax.
What are the Downsides of SQL?
SQL is not a perfect language by any means, but it ranks above other database languages. Still, it does have its disadvantages, which include:
- Lack of control is one disadvantage of SQL; the nature of securing a database system means that SQL is limited in the elements of a database that it can control, meaning database administrators can be limited in what actions they can perform on a database dependent upon security settings, configuration, and proprietary database settings.
- Some versions of SQL can be expensive or, in the case of free versions, can be costly in terms of support and maintenance.
- Some beginning database administrators, database programmers, and data analysts may find certain SQL interfaces to be confusing at first glance; in addition, the different flavors of SQL can be confusing as well, as they each have their own unique statements (regardless of the fact that the main SQL statements are all the same). This can lead to a slight learning curve, especially to those that are new to relational databases management systems or databases in general.
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