query all students
SELECT * FROM student;
selected columns
SELECT name, major
FROM student;
column prefix (will be helpful with “join queries”)
SELECT student.name, student.major
FROM student;
Order
Ascending
SELECT * FROM student
ORDER BY name;
Descending
SELECT *
FROM student
ORDER BY name DESC;
Order by column not selected
SELECT name, major
FROM student
ORDER BY student_id DESC;
Multiple order categories
SELECT * FROM student
ORDER BY major, student_id;
Limit
SELECT * FROM student
LIMIT 2;
With order
SELECT * FROM student
ORDER BY student_id DESC
LIMIT 2;
Where Clause
| operator | meaning |
|---|---|
= |
equal |
> |
greater |
< |
smaller |
>= |
greater equal |
<= |
smaller equal |
<> |
unequal |
SELECT * FROM student
WHERE student_id = 2;
WHERE student_id > 2;
WHERE major = 'Biology';
WHERE major = 'Biology' OR major = 'Math';
WHERE major <> 'Biology';
WHERE major <> 'Biology' AND student_id > 2;
IN word
SELECT * FROM student
WHERE major IN ('Biology', 'Computer', 'Music');
SELECT * FROM student
WHERE name IN ('Gila', 'Sason', 'Simha');