Category Archives: Oracle Sql

Sql  stands for Structured Query Language. is the language to communicate with  the rdbms.  plsql is the programming part of sql

Oracle sql and plsql are the languages which are widely used. They are easy to learn and apply. Here I would be listing out all the articles on Oracle sql and plsql

I am starting the basics so it is very helpful for the beginners to run sql and plsql here

 

Sql Subqueries : Single, Multiple, Scalar and Correlated

Sql SubQueries 1) A Subquery or Nested query is a query within another SQL query and embedded within the WHERE clause. A subquery is a query within a query 2) A subquery is used to return data that will be used in the main query as a condition to further restrict the data to be retrieved. 3) Subqueries answer the queries that have multiple parts. … Continue reading Sql Subqueries : Single, Multiple, Scalar and Correlated »

What are Oracle Joins (Sql Joins)?

Sometimes you need to display data from multiple tables. In order to perform that you need to link one table to another table.There are various ways in which we can obtain data from Multiple tables.Here I would be focusing on Oracle Joins.This is valid for in general any Sql Joins also Oracle Joins A Oracle Joins ( Sql Joins) is a query that combines rows from … Continue reading What are Oracle Joins (Sql Joins)? »

How to resolve ORA-00904: invalid identifier

ORA-00904: invalid identifier is one of the common error seen. Reference: Oracle documentation One of the most common cause of this error Invalid identifier means the column name entered is either missing or invalid. It also Some time comes  when you used reserved word in Oracle database. Check List to resolve the ORA-00904 error  It comes when you put extra comma in the create table … Continue reading How to resolve ORA-00904: invalid identifier »

How to use Oracle SQL*Plus

Here in this post,I would be giving introduction to Oracle sqlplus  which is Oracle tools to connect to database  and how to download Oracle sqlplus Oracle SQL*Plus What is Oracle Sql*plus: 1) SQLPlus, widely used by DBAs and developers, is a powerful and straightforward tool from Oracle to interact with the database. 2) SQLPlus has its own formatting commands to make your queries look better, … Continue reading How to use Oracle SQL*Plus »

how to write sql queries

Last updated on June 21st, 2018 at 05:59 pm What is SQL? Relational Database Management system(RDBMS) contains many tables . These tables are the basic storage in Database. Tables contains the information about something in the real world for example customers ,employees ,deptTables in the database contain zero to many rows. SQL which stands for “Structured Query Language” which is pronounced as “SQL” or “sequel … Continue reading how to write sql queries »

How to use external tables in Oracle with example

Last updated on June 21st, 2018 at 04:49 pmExternal table is one of the important feature in oracle , we will exploring external table in oracle with example in this post What are EXTERNAL TABLES in Oracle? 1)External tables are read only tables where the data is stored in flat files outside the database 2) You can user external table feature to access external files as … Continue reading How to use external tables in Oracle with example »

Oracle Create table Syntax,Tip and Examples

Last updated on June 21st, 2018 at 06:42 pmThis article talks how to create table in Oracle,create table syntax in oracle,oracle create table example, Oracle is the most RDBMS used everywhere for system Table of content What is Oracle database Table How to create table in oracle create table syntax in oracle Privilege required to create table Other characteristics associated with table How to modify the … Continue reading Oracle Create table Syntax,Tip and Examples »

How to delete duplicate rows from Oracle table

Last updated on December 22nd, 2017 at 06:14 pmWe often need to find  and delete duplicate rows from oracle table due to many reasons in the database. We need to delete to clear off the data issues often. There are many ways to oracle delete duplicate rows but keep original .I would be showing off few  faster method to achieve it in this post. Please note … Continue reading How to delete duplicate rows from Oracle table »

REGEXP string Manipulation

String manipulation and searching contribute to a large percentage of the logic within a Webbased application. Regular expressions are a method of describing both simple and complex patterns for searching and manipulating. Usage ranges from the simple (“Find the word SAN in the text”) to the more complex (“Extract all URLs from the text”) to the archaic (“Find all words in which every second character … Continue reading REGEXP string Manipulation »

Oracle Case Statement Explained with Tips and Examples

Last updated on December 24th, 2017 at 02:08 pmWe have seen working of Oracle Decode processing in the previous post Oracle sql decode processing Now let us see Case statement processing Table of content Case statement in Oracle Simple case statement Searchable Case statement Nested Oracle Case statement Important points about Simple and searchable Case statement difference between Case and Decode statement   Case statement … Continue reading Oracle Case Statement Explained with Tips and Examples »

Helpful overview about Oracle cursor

Last updated on September 17th, 2017 at 05:17 pmOracle Cursor Oracle Uses work area called Private SQL areas to execute SQL Statements and store information. A Oracle Cursor is a PL/SQL construct that allows you to name these work areas, and to access their stored information Types of Oracle Cursor Implicit Cursor in Oracle Explicit Cursor in Oracle   Implicit cursor in Oracle Explicit Cursor … Continue reading Helpful overview about Oracle cursor »

How to alter table add column oracle

Last updated on April 1st, 2017 at 08:11 am-You Add a new column using the ALTER TABLE statement. – The table must be contained in your schema To alter a table, or you should either have  ALTER object privilege for the table or the ALTER ANY TABLE system privilege. -If a view, materialized view, trigger,  function-based index, check constraint, function, procedure of package depends on a base table, the … Continue reading How to alter table add column oracle »