ORACLE QUERIES Select, Insert, Update, Delete, Drop, Alter table, and Create are the few queries among many that can be executed in an Oracle database.
Oracle Select Query: Uses: To fetch records from the database.
Syntax: To select records from a table.
SELECT * from table_name;
Example:
SELECT * from students; |
Oracle Insert Query: Uses: To insert records into a table. Syntax:
INSERT into table_name VALUES(value1, value2, .. valuen);
Example:
INSERT into students VALUES(10, 'Joy', 5); |
Oracle Update Query: Uses: To update records of a table.
Syntax:
UPDATE table_name SET column_name1 = value1, column_name2 = value2 WHERE conditions;
Example:
UPDATE students SET name = 'Joy', age = 5 WHERE id = 10; |
Oracle Delete Query: Uses: To delete records of a table.
Syntax:
DELETE from table_name WHERE conditions;
Example:
DELETE from students WHERE id = 10; |
Oracle Truncate Table Query: Uses: To truncate or remove records of a table but not the structure.
Syntax:
TRUNCATE TABLE table_name;
Example:
TRUNCATE TABLE students; |
Oracle Drop Query: To drop a table or a view.
Syntax: To drop a table.
DROP TABLE table_name;
Syntax: To drop a view.
DROP VIEW view_name;
Example: Dropping a table.
DROP TABLE students; |
Oracle Create Query: Uses: To create a sequence, procedure, table, view, or a function.
Syntax: To create a table.
CREATE TABLE table_name ( column_1 data_type [ NULL | NOT NULL ], column_2 data_type [ NULL | NOT NULL ], ... column_n data_type [ NULL | NOT NULL ] );
Syntax: To create a view.
CREATE VIEW view_name AS SELECT column_1, column_2, … column_n FROM tables WHERE view_conditions;
Example: Creating a table.
CREATE TABLE students ( id number(10) NOT NULL, name varchar2(50) NOT NULL, age number(100)); |
Oracle Alter Query: Uses: To add, modify, delete or drop columns of a table.
Syntax: To add columns in a table.
ALTER TABLE table_name ADD column data_type [ NULL | NOT NULL ] ;
Example: Adding a column in a table.
ALTER TABLE students ADD city varchar2(100); |
