Keep it Simple and Smart
About this Book Oracle 2 Day DBA is a database administration quick start guide that teaches you how to perform common day-to-day database administrative tasks. The goal of this book is to give you adequate information to help you understand the concepts behind the Oracle Database. It teaches you how
» Read moreFor all intents and purposes you can consider a user to be a schema and a schema to be a user. A schema is the set of objects (tables, views, indexes, etc) that belongs to an user account. It is often used as another way to refer to an Oracle
» Read moreFirst I would like to share some background of this post. As I have SQL Server background (you can see in my profile here) and when I started learning Oracle. I have so many basic questions regarding oracle environment. Even I was little lit bit confused about few things. But
» Read moreON DELETE CASCADE: When a referenced parent table row is removed the entire child are removed automatically. Example: — Create a Table as mytable1 having the PRIMARY KEY CREATE TABLE MYTABLE1 ( ID INTEGER PRIMARY KEY, EMP_NAME VARCHAR2(10) ); — Create a Table as mytable2 having the FOREIGN KEY CREATE
» Read moreIf you have user that owns objects and you want to drop the user then you have to use the Cascade keyword with your drop statement/command. The Oracle DROP USER CASCADE command drops a user and all owned objects. Without using DROP USER CASCADE you cannot delete the user that
» Read moreHow to get the Second highest/ largest Value from the column ? Example: See the table values in the snapshot. As per requirement we need to get second highest/ largest salary form the column sal which is 3000 as per column values. Solution: Script: select ename,sal from ( select ename,
» Read moreWe can create a trigger with multiple actions (i.e. Insert or Update or Delete) here sharing an example of trigger in which we can handle three actions as insert, update and delete. Example: CREATE OR REPLACE TRIGGER EMPLOYEE_AI_AU_AD AFTER INSERT OR UPDATE OR DELETE ON EMPLOYEE FOR EACH ROW DECLARE
» Read moreDatabases, tablespaces, and datafiles are closely related, but they have important differences. It is important to know the differences for Newbie that‘s why sharing here. Databases: An Oracle database consists of one or more logical storage units called tablespaces that collectively store all of the database data. Tablespace: Each tablespace
» Read more— CREATE TABLE CREATE TABLE EMPLOYEE ( ID NUMBER NOT NULL, FIRST_NAME VARCHAR2(10 BYTE), LAST_NAME VARCHAR2(10 BYTE) ); — INSERT SOME VALUES INTO TABLES INSERT INTO EMPLOYEE (ID,FIRST_NAME,LAST_NAME) VALUES (1,'VARINDER','SANDHU'); INSERT INTO EMPLOYEE (ID,FIRST_NAME,LAST_NAME) VALUES (2,'DINESH','SHARMA'); INSERT INTO EMPLOYEE (ID,FIRST_NAME,LAST_NAME) VALUES (3,'RANJOYT','SINGH'); INSERT INTO EMPLOYEE (ID,FIRST_NAME,LAST_NAME) VALUES (4,'VIKRAM','SINGH'); — CREATE
» Read moreWithin a trigger body of a row trigger, two correlation names exist for every column of the table being modified: one for the old column value, and one for the new column value. Depending on the type of triggering statement, certain correlation names might not have any meaning. A trigger
» Read moreVarinder Sandhu is using WP-Gravatar