Keep it Simple and Smart
First 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 moreClick on the “configure” button as below Toad Tool Option dialog box will open then click on the “Auto add…” button Below screen will open after that you can selecte the listed program ( as we selected Notepad) then click “OK” Now you can check the your selected program add
» 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 moreError: ORA-04091: table name is mutating, trigger/function may not see it Cause: Mutating trigger error occurs when a trigger references the table that owns the trigger. So the result is we receive the above error message. Solution: We cannot refer the table in the trigger that owns the trigger. If
» Read moreVarinder Sandhu is using WP-Gravatar