Top 3 Books to learn Oracle PL SQL for Beginners

In this post you will know the  best Oracle Books for beginners to advanced level developers. If you are totally new to database world, first of all start with SQL and once you are really comfortable move on to PLSQL, because the foundation should be strong before going for the procedural extension (PLSQL). Try and learn from Oracle Press Guides which are written by Oracle Subject Matter Experts; often referred to as Oracle ACEs; and are the best available resource for your investment.

The following are some of the best books on Oracle, written by seasoned authors in this field. You will find these books easy to learn and understand.

1. Oracle Database 12c:

Oracle Database 12c The Complete Reference is a guide book that takes you through the features of this amazing programming language.It was developed by Bob Bryla, Kevin Loney. When you want to make use of the functionalities of this programming language to design powerful database, then you will want to know how you can install, tune, and configure it. Set up Oracle Database 12c or upgrade from an earlier version
Design Oracle databases and plan for application implementation
Construct SQL and SQL*Plus statements and execute powerful queries
Secure data with roles, privileges, virtualization, and encryption
Move data with SQL*Loader and Oracle Data Pump
Restore databases using flashback and the Oracle Database Automatic Undo Management feature
Build and deploy PL/SQL triggers, procedures, and packages
Work with Oracle pluggable and container databases
Develop database applications using Java, JDBC, and XML
Optimize performance with Oracle Real Application Clusters .

2. Oracle PL/SQL Programming:

The best Oracle PL/SQL programming guide by the Oracle community,this definitive guide is precisely what you need to make the most of Oracle's powerful procedural language. This book contains the features and capabilities of pl/sql up through Oracle Database 12c.It Includes optimize PL/SQL performance with features like the function result cache and Oracle utilites such as PL/Scope the PL/SQL hierarchical profiler. Build modular,easy-to-maintain PL/SQL applications using packages,procedures,functions,and triggers.

3. Oracle Essentials:

Oracle Essentials is a simple book that contains beautiful examples and illustrations on how you can use this programming language in an efficient manner. You find out more on Oracle options, products, overall architecture for Oracle Database 11g, data structures, and others. You also learn how you can manage, run, monitor Oracle. You are taught Real Application Testing, Automatic Memory Management, query result set caching, and others. This is one of the best reference books you can lay your hands on.

SQL GROUP BY AND HAVING CLAUSE WITH EXAMPLES

This is one of the important topic in SQL,we have discussed joins in SQL already. SQL includes many aggregate functions,which take information from multiple rows and aggregate it down to produce fewer rows in the final result set."It is used to group the results from one or more tables".

When to use Group By clause?

In fact, if you use select statement  the entire table records  formed as one group by group functions.When we need aggregations like below,we have to use Group by Clause:

• Department-wise total salary of employees
• Month-wise count of employees joined
• Account type and branch-wise average balance maintained

Syntax:

SELECT column_name,function(column_name)

from table_name

GROUP BY column_name

Here is i am taking employee table from them list out job designation_wise number of employees working and total salary from employee table

From the above employee table list out the  job designation_wise and total salary of employees.

Example:

SELECT job,count(*) no_of_employees,sum(sal) total_salary from Employee e

GROUP BY job;

Here job is the column by which rows of employees table are grouped

Result will be:

Having Clause:

The Having clause allows us to filter out groups that do not meet a specific requirement.It is used to mention condition in GROUP based SQL function like WHERE clause.

WHERE clause is executed on actual rows of the table being required.

Syntax:

SELECT column_name,function(column_name)

from table_name 

WHERE column_name condition

GROUP BY column_name

Having function(column_name)condition

Now, we will list out  from the above employee table  department wise no of employees and average salary,of those employees who do not get a commission and only for those departments in which employees get a at least a salary of 25000 or above.

Example:

SELECT Dept_no,count(*)no_of_employees,avg(sal)Avg_sal

from employees

where COM is NULL

GROUP BY Dept_no

Having Min(sal)>=20000

Order By Avg_sal DESC