Average

This method is used to compute the average value of the target field.

Code Snippets

Below is the sample code that averages the column Value from a [dbo].[Sales] table for a specific customer since yesterday.

using (var connection = new SqlConnection(connectionString))
{
    var customerExpenses = connection.Average<Sales>(e => e.Value,
        e => e.CustomerId == 10045 && e.DateInsertedUtc >= DateTime.UtcNow.Date.AddDays(-1));
}

Targeting a Table

You can also target a specific table by passing the literal table and field name like below.

using (var connection = new SqlConnection(connectionString))
{
    var customerExpenses = connection.Average("[dbo].[Sales]", Field.From("Value"), new { State = "Michigan" });
}

Or, use the QueryGroup or QueryField if you are to enhance the WHERE expressions.

using (var connection = new SqlConnection(connectionString))
{
    var where = new []
    {
        new QueryField("CustomerId", 10045),
        new QueryField("DateInsertedUtc", Operation.GreaterThanOrEqual, DateTime.UtcNow.Date.AddDays(-1))
    }
    var customerExpenses = connection.Average("[dbo].[Sales]", Field.From("Value"), where);
}

Table Hints

To pass a hint, simply write the table-hints and pass it in the hints argument.

using (var connection = new SqlConnection(connectionString))
{
    var customerExpenses = connection.Average<Sales>(e => e.Value,
        e => e.CustomerId == 10045 && e.DateInsertedUtc >= DateTime.UtcNow.Date.AddDays(-1),
        hints: "WITH (NOLOCK)");
}

Or, you can use the SqlServerTableHints class.

using (var connection = new SqlConnection(connectionString))
{
    var customerExpenses = connection.Average<Sales>(e => e.CustomerId == 10045 && e.DateInsertedUtc >= DateTime.UtcNow.Date.AddDays(-1),
        hints: SqlServerTableHints.NoLock);
}