What is SQL?

What is SQL? It is a domain-specific language specifically designed for managing data in relational database management systems. Its primary purpose is to enable stream processing within such systems. However, it can also be used for other purposes, such as managing user accounts or creating reports. ANSI and ISO standards also help to define it.

Structured Query Language

Structured Query Language (SQL) is a language that enables the management of data in relational data stream management systems. The language is domain-specific, which means it is optimized for managing data in these systems.

MySQL

MySQL is a relational database management system that supports all common programming languages. It supports multiple storage engines and does not consume a lot of space. Its built-in tool, MySQL Workbench, allows you to create, manage, and maintain a database. The database is protected against external manipulation and does not take up a lot of space. However, the downside of MySQL is that it is vulnerable to security threats.

ANY

If you are a software developer or database administrator, you probably heard of ANSI for SQL or Structured English Query Language (SQL). This language was originally called SEQUEL, but the name has since been changed. The word is typically pronounced “sequel,” though some prefer the more non-acronym pronunciation of “ess-cue-el.” ANSI is an organization that has been involved in developing standards for the language since its development.

ISO

When it comes to a database language, you have many options. You can choose from SQL or ISO/IEC 9075. Both of these standards describe the structure of data and operations. Both standards are derived from the International Electrotechnical Commission or ISO. They have a similar conceptual framework but differ in how they define and process statements.

Tables

Tables are collections of related data held in a table format within a database. They consist of rows and columns.

SELECT clause

The SELECT clause in SQL allows you to specify the columns you wish to include in the result. While SQL is not case-sensitive, you should capitalize your columns to make your code more readable. The SELECT clause specifies one or more columns and can include a wildcard character (*) to indicate all columns. It also supports a limit on the number of rows you want to return, which is useful for testing purposes and avoids consuming too many resources.

Predicates

Predicates in SQL can be used to qualify rows in a SELECT statement. They evaluate two boolean values. One predicate returns TRUE if the argument is true, while the other returns FALSE. The predicate EXISTS is a subquery that tests whether a given column contains at least one row.

JOIN clause

In SQL, the JOIN clause allows records from two or more statements to be joined together. It is a subset of the standard and does a join with a specified join condition. This join condition may be a Boolean expression and must be enclosed in parentheses. The JOIN clause always modifies the FROM clause, and it is possible to specify two named sources in the FROM clause. In this case, each table must have a dot-qualified name.