Exists

This method is used to check whether the rows are existing in the table.

Code Snippets

Below is the sample code to check whether a row is existing from the [dbo].[Person] table.

using (var connection = new SqlConnection(connectionString))
{
    var existing = connection.Exists<Person>(10045);
}

Or, you can use the Linq to enhance the expression.

using (var connection = new SqlConnection(connectionString))
{
    var existing = connection.Exists<Person>(e =>
        e.Name == "Doe" && e.DateOfBirth =  DateTime.Parse("2000-01-01"));
}

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 existing = connection.Exists("[dbo].[Person]", 10045);
}

Or, you can use the QueryGroup or QueryField to enhance the expression.

using (var connection = new SqlConnection(connectionString))
{
    var where = new []
    {
        new QueryField("Name", "Doe"),
        new QueryField("DateOfBirth", DateTime.Parse("2000-01-01"))
    };
    var existing = connection.Exists("[dbo].[Person]", 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 existing = connection.Exists<Person>(10045,
    hints: "WITH (NOLOCK)");
}

Or, you can use the SqlServerTableHints class.

using (var connection = new SqlConnection(connectionString))
{
    var existing = connection.Exists<Person>(10045,
    hints: SqlServerTableHints.NoLock);
}