# Set parameters

In this section, you will learn how to set parameters in the .NET SDK for SurrealDB.

Within your application, you can define parameters that can be used to store and retrieve data from SurrealDB.
Parameters are used to store data in a structured format, and can be used to store data in a key-value pair format.

>[!IMPORTANT]
> Parameters allow you to define global (database-wide) parameters that are available to every client.

<table>
	<thead>
		<tr>
			<th scope="col">Method</th>
			<th scope="col">Description</th>
		</tr>
	</thead>
	<tbody>
		<tr>
			<td scope="row" data-label="Method"><a href="#set"> <code> db.Set(key, value) </code></a></td>
			<td scope="row" data-label="Description">Assigns a value as a parameter for this connection</td>
		</tr>
        <tr>
            <td scope="row" data-label="Method"><a href="#unset"> <code> db.Unset(key) </code></a></td>
            <td scope="row" data-label="Description">Removes a parameter for this connection</td>
        </tr>
	</tbody>
</table>

## `.Set()` {#set}

Assigns a value as a parameter for this connection.

```csharp title="Method Syntax"
await db.Set(key, val)
```

### Arguments

<table>
    <thead>
        <tr>
            <th colspan="2" scope="col">Arguments</th>
            <th colspan="2" scope="col">Description</th>
        </tr>
    </thead>
    <tbody>
        <tr>
            <td colspan="2" scope="col" scope="row" data-label="Arguments">
                <code>key</code>
                <label label="required" />
            </td>
            <td colspan="2" scope="col" scope="row" data-label="Description">
                Specifies the name of the variable.
            </td>
        </tr>
        <tr>
            <td colspan="2" scope="col" scope="row" data-label="Arguments">
                <code>value</code>
                <label label="required" />
            </td>
            <td colspan="2" scope="col" scope="row" data-label="Description">
                Assigns the value to the variable name.
            </td>
        </tr>
        <tr>
            <td colspan="2" scope="col" scope="row" data-label="Arguments">
                <code>cancellationToken</code>
                <label label="optional" />
            </td>
            <td colspan="2" scope="col" scope="row" data-label="Description">
                The cancellationToken enables graceful cancellation of asynchronous operations.
            </td>
        </tr>
    </tbody>
</table>

### Example usage

```csharp
// Assign the variable on the connection
await db.Set("name", new Name { FirstName = "Tobie",
    LastName = "Morgan Hitchcock" });

// Use the variable in a subsequent query
await db.Query($"CREATE person SET name = $name");

// Use the variable in a subsequent query
await db.Query($"SELECT * FROM person WHERE name.first_name = $name.first_name");
```

<br />

## `.Unset()` {#unset}

Removes a parameter for this connection.

```csharp title="Method Syntax"
await db.Unset(key)
```

### Arguments

<table>
    <thead>
        <tr>
            <th colspan="2" scope="col">Arguments</th>
            <th colspan="2" scope="col">Description</th>
        </tr>
    </thead>
    <tbody>
        <tr>
            <td colspan="2" scope="col" scope="row" data-label="Arguments">
                <code>key</code>
                <label label="required" />
            </td>
            <td colspan="2" scope="col" scope="row" data-label="Description">
                Specifies the SurrealQL statements.
            </td>
        </tr>
        <tr>
            <td colspan="2" scope="col" scope="row" data-label="Arguments">
                <code>cancellationToken</code>
                <label label="optional" />
            </td>
            <td colspan="2" scope="col" scope="row" data-label="Description">
                The cancellationToken enables graceful cancellation of asynchronous operations.
            </td>
        </tr>
    </tbody>
</table>

### Example usage

```csharp
await db.Unset("name");
```