3. AGENDA
INTRODUCTION TO THE SQL
BASIC CONCEPTS OF SQL
JOINS IN SQL
TYPES OF JOINS IN SQL
SOME FAQ’S
4. WHAT IS SQL ?
• SQL is a database computer language designed for the retrieval and
management of data in a relational database.
• SQL stands for Structured Query Language.
• RDBMS stands for Relational Database Management System.
• All the Relational Database Management Systems (RDMS) like
MySQL, MS Access, Oracle, Sybase, Informix, Postgres and SQL
Server use SQL as their standard database language.
5. BASIC CONCEPTS OF SQL
The data in an RDBMS is stored in database objects which are called
as tables.
Every table is broken up into smaller entities called fields which are also
known as column.
A record or tuple is also called as a row of data is each individual entry that
exists in a table.
A NULL value in a table is a value in a field that appears to be blank, which
means a field with a NULL value is a field with no value.
6. JOINS IN SQL
•As the name shows, JOIN means to combine something.
•The SQL Joins clause is used to combine records from two or
more tables in a database.
•The SQL JOIN clause takes records from two or more tables in
a database and combines it together.
7. WHY JOIN IS USED IN SQL
•If you want to access more than one table through a select
statement.
•If you want to combine two or more table then SQL JOIN
statement is used .
•It combines rows of that tables in one table and one can
retrieve the information by a SELECT statement.
•The joining of two or more tables is based on common field
between them.
8. TYPES OF JOINS
Inner Join.
Left (Outer) Join.
Right (Outer) Join.
Full (Outer) Join.
9. INNER JOIN
•The most important and frequently used of the joins is
the INNER JOIN.
•They are also referred to as an EQUIJOIN.
•The basic syntax of the INNER JOIN is as follows.
SELECT table1.column1, table2.column2...
FROM table1
INNER JOIN table2
ON table1.common_field =
table2.common_field;