W- Willpower, Wisdom
A- Attitude, Ambition, Assertiveness, Aim
T- Time management, Thinking, Trust
C- Communication skills, Concentration, Confidence, Consistency, Courage,
Cheerfulness, Commitment
H- Humbleness, Hardwork, Humanity, Honesty, Humour, Health
M- Memory, Money, Music, Motivation, Morale
E- Enthusiasm, Exercise, Energy, Efforts, Entertainment, Ethics
G- God, Guts, Guidance, Goodness, Goals, Genuineness
O- Optimism, Opportunity, Obligation, Observation
D- Daring, Dedication, Diplomacy, Determination, Dignity, Discipline, Dreams
Saturday, October 6, 2012
Oracle Topics and Example
Type of Data Command in SQL
DDL -- Create, Alter, Drop, Rename, Comment, Truncate
Create is used to create a table
Alter is used to change the structure of the table
The drop is used to removing the structure of table and data.
Rename is used to renaming the name of the table and column of the table.
Comment is used to an additional description about table or column in the database.
DML --- Insert, Update, Delete, Merge
Insert is used to insert the data into tables.
The update is used to modify the content of the data in the table.
Delete is used to deleting the data from table using where condition option.
Merget is used to execute 2 operations at a time insert and update in a single command.
TCL --- Commit, Rollback, Savepoint
this is transactions command. This DDL command is auto-commit.
this command is used whenever we are using DML operations.
Commit is used to permit commit into the database
Rollback is used to go back the previous status.
Savepoint is like a checklist for the data to saving point when we required we rollback using save point checklist
DCL-- Grant and Revoke
Grant is used for the user can read & write on a certain database objects
Revoke withdraw access privileges given with the GRANT command
SQL Constraints
Not Null, Unique, Primary Key, Foreign Key, Check, Default, Index
NOT NULL - Ensures that a column cannot have a NULL value
UNIQUE - Ensures that all values in a column are different
PRIMARY KEY - A combination of a NOT NULL and UNIQUE. Uniquely identifies each row in a table
FOREIGN KEY - Uniquely identifies a row/record in another table
CHECK - Ensures that all values in a column satisfy a specific condition
DEFAULT - Sets a default value for a column when no value is specified
INDEX - Used to create and retrieve data from the database very quickly
Different Types of SQL JOINs
Here are the different types of the JOINs in SQL:
(INNER) JOIN: Returns records that have matching values in both tables
LEFT (OUTER) JOIN: Return all records from the left table, and the matched records from the right table
RIGHT (OUTER) JOIN: Return all records from the right table, and the matched records from the left table
FULL (OUTER) JOIN: Return all records when there is a match in either left or right table
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