# **NOT,!**

## **Operator Description**

`NOT,!` logical operator is used for *logical non-* operations. If the operand is zero, the result is `true`; if the operand is non-zero, the result is `false`; if the operand is `NOT NUL`, the result is `NULL`.

## **Grammar Structure**

```sql
SELECT not column_name FROM table_name;
```

## **Example**

```text
mysql> select not 0;
+--------+
| not 0 |
+--------+
| true |
+--------+
1 row in set (0.02 sec)
mysql> select not null;
+-------------+
| not null |
+-------------+
| NULL |
+-------------+
1 row in set (0.00 sec)
mysql> select not 1;
+--------+
| not 1 |
+--------+
| false |
+--------+
1 row in set (0.01 sec)
```

```text
create table t1 (a boolean,b bool);
insert into t1 values (0,1),(true,false),(true,1),(0,false),(NULL,NULL);

mysql> select not a and not b from t1;
+-----------------------+
| not a and not b |
+-----------------------+
| false |
| false |
| false |
| true |
| NULL |
+-----------------------+
5 rows in set (0.00 sec)
```

## **limit**

MatrixOne does not support the `!` operator for the time being.