PostgreSQL WHERE - Filter Data

Filter Records

The WHERE clause is used to filter records.

It is used to extract only those records that fulfill a specified condition.

If we want to return only the records where city is London, we can specify that in the WHERE clause:

SELECT * FROM customers
WHERE city = 'London';

PostgreSQL requires quotes around text values.

However, numeric fields should not be enclosed in quotes:

SELECT * FROM customers
WHERE customer_id = 19;

Quotes around numeric fields will not fail, but it is good practice to always write numeric values without quotes.

Use the > operator to return all records where customer_id is greater than 80:

SELECT * FROM customers
WHERE customer_id > 80;

Quotes around numeric fields will not fail, but it is good practice to always write numeric values without quotes.