In SQL, the <code>NOT NULL</code> constraint is used to specify that a column cannot contain any NULL values. When you define a column with the <code>NOT NULL</code> constraint, it means that every row inserted into the table must have a value for that column.
Here's an example of how you can use the <a target="_blank" href="https://www.almabetter.com/bytes/tutorials/sql/not-null-in-sql"><code>NOT NULL</code> constraint</a> when creating a table:
<pre><code class="lang-sql">sqlCopy codeCREATE TABLE Employee (
 ID INT PRIMARY KEY,
 Name VARCHAR(50) NOT NULL,
 Age INT NOT NULL,
 Department VARCHAR(50)
);
</code></pre>
In this example, both the <code>Name</code> and <code>Age</code> columns have the <code>NOT NULL</code> constraint specified, meaning that every entry in the <code>Employee</code> table must have values for these columns. If you try to insert a row without providing a value for a <code>NOT NULL</code> column, the database will throw an error. Practice with this <a target="_blank" href="https://www.almabetter.com/online-compiler/sql">free SQL compiler</a>!

In SQL, the `NOT NULL` constraint is used to specify that a column cannot contain any NULL values. When you define a column with the `NOT NULL` constraint, it means that every row inserted into the table must have a value for that column.

Here's an example of how you can use the [`NOT NULL` constraint](https://www.almabetter.com/bytes/tutorials/sql/not-null-in-sql) when creating a table:

```sql
sqlCopy codeCREATE TABLE Employee (
    ID INT PRIMARY KEY,
    Name VARCHAR(50) NOT NULL,
    Age INT NOT NULL,
    Department VARCHAR(50)
);
```

In this example, both the `Name` and `Age` columns have the `NOT NULL` constraint specified, meaning that every entry in the `Employee` table must have values for these columns. If you try to insert a row without providing a value for a `NOT NULL` column, the database will throw an error. Practice with this [free SQL compiler](https://www.almabetter.com/online-compiler/sql)!

NOT NULL in SQL