SQL
SQL stands for Structured Query Language and is widely used in relational database systems, such as MySQL, PostgreSQL, MariaDB, and SQLite.
An SQL query enables the extraction of the required information from the database. For example, you can define displaying data from specific columns that correspond to a certain range. So, when the desired operation is “Select all records from the table ‘contacts’ that take the value ‘YES’ in the column ‘partner’, but max 500 records”, the SQL query would look like this:
SELECT *
FROM contacts
WHERE partner = ‘YES’
LIMIT 500
Commands written in SQL are divided into four basic categories: commands defining data (e.g., CREATE), commands manipulating data (e.g., SELECT), commands controlling data (e.g., GRANT), and other commands. However, different languages more or less respect SQL standards; for example, MySQL deviates from them more than PostgreSQL.
