SQL WHERE

SQL Where clause is used to filter records in a database table, allowing you to retrieve only the rows that meet specific conditions.

SQL Where Syntax

SELECT column1, column2, ...
FROM table_name
WHERE condition;

SELECT column1, column2, ...

FROM table_name

WHERE condition;

SQL Where Examples

SQL Where Filtering by a Single Condition Example

This query retieves all columns from the students table for rows where the NAME starts with the letter ‘A’.

SELECT * FROM Students
WHERE name LIKE 'A%';

SELECT * FROM Students

WHERE name LIKE 'A%';

SQL Where Combining Multiple Conditions with AND

This query retrieves all columns from the PATIENTS table for rows where the gender is ‘M’ (male) and the contact_number is not NULL.

SELECT * FROM Patients
WHERE gender = 'M' AND contact_number IS NOT NULL;

SELECT * FROM Patients

WHERE gender = 'M' AND contact_number IS NOT NULL;

SQL Where Using OR to Broade the Search

This query retrieves all columns from the DOCTORS table for rows where the specialty is either ‘Cardiology’ or ‘Neurology’.

SELECT * FROM Doctors
WHERE specialty = 'Cardiology' OR specialty = 'Neurology';

SELECT * FROM Doctors

WHERE specialty = 'Cardiology' OR specialty = 'Neurology';

SQL Where Visual Diagram

SQL Where Labs