SQL · Theory

AND OR

Theory

48/439

AND OR

Mix AND and OR only with parentheses. WHERE (city = 'Pune' OR city = 'Goa') AND marks < 40; fail students from those cities.

Without brackets MySQL does AND first. Your English sentence is not the operator order.

Trap — writing AND/OR chains from spoken language without drawing two groups on paper.

On the example next to this theory — AND OR — wHERE combines predicates with AND/OR; LIKE does pattern match.

Exam tip

(city = 'Pune' OR city = 'Goa') AND marks < 40

AND OR — sample query

CREATE TABLE products (id INTEGER PRIMARY KEY, name TEXT, price REAL);
INSERT INTO products VALUES (1, 'Pen', 10), (2, 'Book', 200), (3, 'Bag', 50);
SELECT * FROM products
WHERE price BETWEEN 20 AND 150 AND name LIKE 'B%';

AND OR — wHERE combines predicates with AND/OR; LIKE does pattern match.

Short notes

DefBracket OR groups, then AND the rest.
Rule(A OR B) AND C.
TrapRelying on default precedence.

CREATE TABLE products (id INTEGER PRIMARY KEY, name TEXT, price REAL); INSERT INTO products VALUES (1, 'Pen', 10), (2, 'Book', 200), (3, 'Bag', 50); SELECT * FROM products WHERE price BETWEEN 20 AND 150 AND name LIKE 'B%';

AND OR

AND OR — sample query

Short notes

Questions

AND OR

AND OR — sample query

Short notes

Questions