SQL Guide (Structured Query Language)

SQL Guide


SQL - Structured Query Language (Structured Query Language)

SQL is a standard computer language used to access and manipulate databases.
Common database management systems: MySQL, SQL Server, Access, Oracle, Sybase, and DB2
For those who want to store data and retrieve data from the database people, SQL knowledge is invaluable.

What is SQL?

  • SQL refers to the Structured Query Language (S tructured Q uery L anguage)
  • SQL gives us the ability to access the database
  • SQL is an ANSI standard computer language
  • SQL for database queries executed
  • SQL can retrieve data from the database
  • SQL can insert a new record in the database
  • SQL can delete records from the database
  • SQL is easy to learn

SQL database tables

A database typically contains one or more tables. Each table consists of a name identity (such as "customer" or "Order"). Table contains records with data (rows).
The following example is a table named "Persons" of:

SQL query program

With SQL, we can query a database and get a result set returned.
Discover the program like this:
SELECT LastName FROM Persons
The result set will look like this:
LastName
Hansen
Svendson
Pettersen

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