Method BindColumn

Namespace

YndigoBlue.Velocity.Engine

Assembly

YndigoBlue.Velocity.dll

BindColumn<T>(string)

Binds a single column from query results to a typed enumerable collection by column name.

public IEnumerable<T> BindColumn<T>(string columnName)

Parameters

columnName string

The name of the column to bind.

Returns

IEnumerable<T>

A lazy IEnumerable<T> that streams typed values from the specified column one row at a time.

Type Parameters

T

The type to bind the column values to.

Examples

var conn = new SqlServerDatasourceConnection
{
    Hostname = "localhost",
    Database = "sales_db",
    Username = "sa",
    Password = "password"
};

using (var manager = new Manager(conn))
{
    var schema = manager.LoadSchema("dbo");
    var ordersTable = schema["orders"];

    var query = new Query()
        .Select([ordersTable["order_total"]])
        .From(ordersTable)
        .Where(new Criterion<DateTime>(ordersTable["order_date"], ConditionalType.GreaterThan, DateTime.Today.AddDays(-30)));

    using (ResultReader reader = manager.ExecuteReader(query))
    {
        // Extract just the order_total column as decimals
        foreach (decimal total in reader.BindColumn<decimal>("order_total"))
        {
            Console.WriteLine($"Order total: {total:C}");
        }
    }
}

Remarks

Returns a lazy enumerable backed by yield return. The returned sequence reads from the live database reader and must be iterated inside the enclosing using (ResultReader ...) block. Iterating after the reader has been disposed will throw.

BindColumn<T>(int)

Binds a single column from query results to a typed enumerable collection by column index.

public IEnumerable<T> BindColumn<T>(int columnIndex)

Parameters

columnIndex int

The zero-based index of the column to bind.

Returns

IEnumerable<T>

A lazy IEnumerable<T> that streams typed values from the specified column one row at a time.

Type Parameters

T

The type to bind the column values to.

Remarks

Returns a lazy enumerable backed by yield return. The returned sequence reads from the live database reader and must be iterated inside the enclosing using (ResultReader ...) block. Iterating after the reader has been disposed will throw.

BindColumn<T>()

Binds the first column from query results to a typed enumerable collection.

public IEnumerable<T> BindColumn<T>()

Returns

IEnumerable<T>

A lazy IEnumerable<T> that streams typed values from the first column one row at a time.

Type Parameters

T

The type to bind the column values to.

Remarks

Returns a lazy enumerable backed by yield return. The returned sequence reads from the live database reader and must be iterated inside the enclosing using (ResultReader ...) block. Iterating after the reader has been disposed will throw.