SQL WHERE Clause: Combining Conditions

Logical Operators in SQL WHERE Clause

SQL provides logical operators to combine multiple conditions in the WHERE clause.

The main operators are AND, OR, and NOT.

• AND: Both conditions must be true.
• OR: At least one condition must be true.
• NOT: Negates a condition.

Using AND Operator

The AND operator requires all combined conditions to be true for a record to be included in the result.

It is useful when you want to narrow down results by multiple criteria.

Using OR Operator

The OR operator requires at least one of the combined conditions to be true.

It is useful when you want to broaden your search criteria.

Using NOT Operator

The NOT operator negates a condition, selecting records where the condition is false.

It helps exclude specific data from your results.

Combining Multiple Conditions with Parentheses

When combining AND, OR, and NOT operators, parentheses control the order of evaluation.

Without parentheses, SQL evaluates AND before OR by default, which can lead to unexpected results.

• Use parentheses to group conditions logically.
• This ensures your query filters data as intended.