Sum

This method computes the sum of the target field.

Code Snippets

The following example returns the sum of the Value column from the [dbo].[Sales] table for a specific customer since yesterday.

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

Targeting a Table

To target a specific table, pass the literal table and field name.

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

Use QueryGroup or QueryField to build more complex 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.Sum("[dbo].[Sales]", Field.From("Value"), where: where);
}

Table Hints

Pass a table hint via the hints argument.

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

Or use the SqlServerTableHints class.

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