NOT operator is used in SQL statements to negate a condition or a logical expression. It is a unary operator that takes a single argument and returns the opposite of that argument’s boolean value.
The syntax of the
NOT operator in SQLite is straightforward. It is written as “NOT expression”, where “expression” is any valid SQL expression that evaluates to a boolean value. For example, the following SQL statement selects all rows from a table named “customers” where the “age” column is not equal to 25:
SELECT * FROM customers WHERE NOT age = 25;
In this statement, the NOT operator negates the condition “age = 25”, which means that the query will select all rows where the “age” column is not equal to 25.
NOT operator can also be used with other SQL operators to create more complex conditions. For example, the following SQL statement selects all rows from a table named “orders” where the “status” column is not equal to ‘delivered’ and the “total” column is greater than 1000:
SELECT * FROM orders WHERE NOT status = 'delivered' AND total > 1000;
In this statement, the
NOT operator is used with the logical
AND operator to create a compound condition that includes both the “status” and “total” columns.
It is important to note that the NOT operator has a higher precedence than other operators, such as
OR. This means that any expression that contains the
NOT operator will be evaluated first, before any other operators in the expression.
In conclusion, the SQLite
NOT operator is a powerful tool that can be used to negate conditions and expressions in SQL statements. It can be used to create complex conditions that involve multiple columns and operators, and it has a higher precedence than other operators in SQL expressions.