Table of Contents:

Connect to Oracle Database........................................................................................................................2

Finding your user name...............................................................................................................................3

Create STUDENT table.................................................................................................................................4

SELECT on a Table........................................................................................................................................6

To Select all columns...............................................................................................................................6

To select specific columns.......................................................................................................................6

To select columns in any specific order...................................................................................................6

“Order By” to sort data............................................................................................................................7

“Order By” on NULL data.........................................................................................................................8

“Order By” w/ DESC.................................................................................................................................8

“Order BY” on multiple columns..............................................................................................................9

“Order By” using Number........................................................................................................................9

Major (vs) Minor sort.............................................................................................................................10

Alias a column........................................................................................................................................11

Comments: Single Line, Multi Line.........................................................................................................12

WHERE Clause...........................................................................................................................................14

Basic Where clauses..............................................................................................................................14

OR clause...............................................................................................................................................14

Double (vs) Single Quote.......................................................................................................................14

Operations on NULL value.....................................................................................................................15

Order of precedence.............................................................................................................................16

IN operator............................................................................................................................................16

NULL + NOT IN.......................................................................................................................................17

BETWEEN/ NOT BETWEEN.....................................................................................................................18

LIKE........................................................................................................................................................18

DISTINCT (vs) Group BY.........................................................................................................................19

FETCH Clause.........................................................................................................................................19

Connect to Oracle Database

Finding your user name

Create STUDENT table

DROP TABLE STUDENT;

CREATE TABLE student (sid NUMBER, fname CHAR(20), lname CHAR(20), class_code CHAR(2), grade_pt NUMBER(3,2) );

describe student

INSERT INTO student VALUES (501, 'Ravi', 'Nandigam', 'CS', 4.00);INSERT INTO student VALUES (502, 'Mike', 'B', 'EC', 3.92);INSERT INTO student VALUES (503, 'Tammy', 'A', 'ME', 2.10);INSERT INTO student VALUES (504, 'Elmer', 'Andy', 'CS', 5.00);INSERT INTO student VALUES (505, 'Srini', 'M', 'EC', 1.92);INSERT INTO student VALUES (506, 'Amar', 'Kaka', 'CI', 0.92);INSERT INTO student VALUES (507, 'Zaheer', 'Khan', NULL, NULL);INSERT INTO student VALUES (508, 'Mahesh', 'ch', 'ME', NULL);INSERT INTO student VALUES (509, 'Susan', 'abc', 'EC', 2.00);INSERT INTO student VALUES (510, 'Sarada', 'K', 'CS', 4.50);COMMIT;

SELECT on a Table

To Select all columnsSELECT * FROM STUDENT;

To select specific columnsselect fname, class_code, grade_pt from student;

To select columns in any specific orderselect class_code, lname, sid from student;

“Order By” to sort dataselect * from student order by fname;

“Order By” on NULL dataselect * from student order by grade_pt;

“Order By” w/ DESCselect * from student order by grade_pt desc;

“Order BY” on multiple columnsselect sid, fname, lname from student order by class_code, grade_pt;

“Order By” using Numberselect sid, fname, lname from student order by sid;select sid, fname, lname from student order by 1;

Major (vs) Minor sortselect * from student order by lname, class_code;

Alias a columnselect sid “Student ID”, fname “First Name”, lname “Last Name” from student;

SELECT sid as “Student Id” from student;

Comments: Single Line, Multi Line

WHERE Clause

Basic Where clauses

OR clause

Double (vs) Single Quote

Operations on NULL value

Note: NULL means UNKNOWN data, so EQUAL(=) won’t work.

Order of precedence

Note: () , NOT, AND, OR

IN operator

NULL + NOT IN

BETWEEN/ NOT BETWEEN

LIKE

Note: CHAR data will be padded with spaces at the end. Hence, second query above didn’t return any record.

Note2: Use trim to remove trailing spaces

DISTINCT (vs) Group BY

FETCH Clause