MySQL WHERE Clause

The WHERE clause is used for filtering records in MySQL queries. It specifies conditions that records must meet to appear in the result. WHERE can be used with SELECT, UPDATE, DELETE and other SQL statements. Basic syntax:

SELECT column1, column2
FROM table_name
WHERE condition;

EXAMPLE

SELECT * FROM duplicated_table WHERE country = "UK";

WHERE country = "UK" AND city = "London";

SELECT * FROM first_table WHERE age > 30;

SELECT * FROM duplicated_table WHERE city LIKE "L%";

RESULT

In the WHERE clause, you can use the following operators:

Operator	Description	Usage Example
=	Equal	WHERE name = "John"
>	Greater than	WHERE age > 30
<	Less than	WHERE age < 25
>=	Greater than or equal	WHERE age >= 18
<=	Less than or equal	WHERE price <= 100
<> or !=	Not equal	WHERE country <> "Germany"
AND	Combines multiple conditions, all must be true	WHERE age > 20 AND country = "UK"
BETWEEN	Between a certain range	WHERE age BETWEEN 18 AND 30
LIKE	Search for a pattern in text	WHERE name LIKE "J%"
IN	Specifies multiple possible values for a column	WHERE country IN ("UK", "USA")
NOT	Negation of other operators	WHERE NOT country = "Germany"
OR	Alternative conditions, at least one must be true	WHERE city = "London" OR city = "Paris"

Conditions can include:

Comparison operators (=, >, <, >=, <=, !=)
Logical operators (AND, OR, NOT)
IN, BETWEEN, LIKE and other operators

The WHERE clause is a powerful tool for:

Filtering data by specific values
Finding records within a range
Combining multiple conditions
Pattern matching with LIKE
Checking for NULL values