Oracle & SQL

Oracle Data Types Character Data Types: Char(2) Varchar (20) Clob: large character string as long as 4GB Bolb and bfile: large amount of binary file Numeric Data Types: Number: used to store real numbers Binary float & binary double: to store data in a floating –point format Date and Time Data Types: Date: stores date & time Timestamp: stores time values that are precise to fractional seconds Conversion functions: TO_CHAR: floating number to a string TO_NUMBER: floating number or string to a number TO_DATE: character data to a DATE data type TO_TIMESTAMP:

SQL Statements Data Manipulation: SELECT INSERT DELETE UPDATE Data Definition: CREATE TABLE DROP TABLE ALTER TABLE CREATE VIEW DROP VIEW CREATE INDEX DROP INDEX CREATE SCHEME DROP SCHEME CREATE DOMAIN DROP DOMAIN Access Control: GRANT REVOKE

Transaction Control: COMMIT: Ends the current transaction ROLLBACK: Aborts the current transaction SET TRANSACTION: Define the data access char. Programmatic Control: DECLARE EXPLAIN OPEN FETCH CLOSE PREPARE EXECUTE DESCRIBE

Sql Operators Comparison operator: Between: tests whether a value is between a pair of value IN: test whether a value is in a list of values LIKE: Tests whether a value follows a certain pattern Logical Operator: AND, OR, NOT, GE, LE The set Operator: UNION: combines the result of more than one select statement after removing any duplicate rows NUION ALL: INTERSECTION: MINUS: returns the rows returned by the first query that aren’t in the second query’s result.

SQL Functions Single-Row Functions: CONCAT: puts together two or more character strings into one string LENGTH: length of character string LOWER: uppercase letter to lower case SUBSTR: part of string INSTR: number indicating where in a string a certain string value starts. REPLACE: Aggregate Functions: MIN MAX AVG SUM COUNT: total number of columns COUNT(*) : number of rows in a table Number & Date Functions: ROUND TRUNC TO_DATE