The AND & OR Clauses

The AND & OR clauses

The SQL AND & OR operators are used to combine multiple conditions in order to narrow data in an SQL statement. These two operators are called the conjunctive operators.

These operators provide a means to make multiple comparisons with different operators in the same SQL statement.

The AND Operator

The AND operator allows the existence of multiple conditions in a SQL statement’s WHERE clause.

Syntax

The basic syntax of the AND operator with a WHERE clause is as follows:

SELECT column1, column2, ... columnN 

FROM table_name

WHERE [condition1] AND [condition2]...AND [conditionN];

You can combine N number of conditions using the AND operator. For an action to be taken by the SQL statement, whether it be a transaction or a query, all conditions separated by the AND must be TRUE.

Example

In this example, we will retrieve the ID, Name and Salary fields from the CUSTOMERS table, where the salary is greater than $20,000 (inclusive) and the age is less than 25 years.

The steps needed to solve this problem are highlighted below: