Welcome

SQL is a standard language for accessing databases.

 

  • SQL stands for Structured Query Language
  • SQL lets you access and manipulate databases
  • SQL is an ANSI (American National Standards Institute) standard

Our SQL tutorial will teach you how to use SQL to access and manipulate data in: MySQL, SQL Server, Access, Oracle, Sybase, DB2, and other database systems.

As we have IDE for other coding language like eclipse or JDeveloper, TOAD is the IDE for SQL and lost of DBAs are very familiar with this IDE, so we will use it in our examples where neccessary.

SQL Capabilities

  • SQL can execute queries against a database
  • SQL can retrieve data from a database
  • SQL can insert records in a database
  • SQL can update records in a database
  • SQL can delete records from a database
  • SQL can create new databases
  • SQL can create new tables in a database
  • SQL can create stored procedures in a database
  • SQL can create views in a database
  • SQL can set permissions on tables, procedures, and views

SQL Standardizations

Although SQL is an ANSI (American National Standards Institute) standard, there are different versions of the SQL language.

However, to be compliant with the ANSI standard, they all support at least the major commands (such as SELECT, UPDATE, DELETE, INSERT, WHERE) in a similar manner.

RDBMS stands for Relational Database Management System.

RDBMS is the basis for SQL, and for all modern database systems such as MS SQL Server, IBM DB2, Oracle, MySQL, and Microsoft Access.

The data in RDBMS is stored in database objects called tables. A table is a collection of related data entries and it consists of columns and rows.

Example:


SELECT * FROM Customers;

What Next?

Next we will learn basic syntaxes and keywords for SQL.