/// <summary>
/// Executes command and returns results as collection of values, mapped using provided mapping function.
/// </summary>
/// <typeparam name="T">Result record type.</typeparam>
/// <param name="objectReader">Record mapping function from data reader.</param>
/// <returns>Returns collection of query result records.</returns>
public IEnumerable <T> Query <T>(Func <IDataReader, T> objectReader)
{
DataConnection.InitCommand(CommandType, CommandText, Parameters, null);
if (Parameters != null && Parameters.Length > 0)
{
SetParameters(DataConnection, Parameters);
}
return(ReadEnumerator(DataConnection.ExecuteReader(GetCommandBehavior()), objectReader));
}
/// <summary>
/// Executes command and returns results as collection of values, mapped using provided mapping function.
/// </summary>
/// <typeparam name="T">Result record type.</typeparam>
/// <param name="objectReader">Record mapping function from data reader.</param>
/// <returns>Returns collection of query result records.</returns>
public IEnumerable <T> Query <T>(Func <IDataReader, T> objectReader)
{
DataConnection.InitCommand(CommandType, CommandText, Parameters, null);
if (Parameters != null && Parameters.Length > 0)
{
SetParameters(DataConnection, Parameters);
}
using (var rd = DataConnection.ExecuteReader(GetCommandBehavior()))
while (rd.Read())
{
yield return(objectReader(rd));
}
}
static T ExecuteScalar <T>(DataConnection connection, string sql)
{
using (var rd = connection.ExecuteReader())
{
if (rd.Read())
{
var objectReader = GetObjectReader <T>(connection, rd, sql);
#if DEBUG
//var value = rd.GetValue(0);
#endif
try
{
return(objectReader(rd));
}
catch (InvalidCastException)
{
return(GetObjectReader2 <T>(connection, rd, sql)(rd));
}
}
}
return(default(T));
}
static IEnumerable <T> ExecuteQuery <T>(DataConnection connection)
{
using (var rd = connection.ExecuteReader())
{
if (rd.Read())
{
var objectReader = GetObjectReader <T>(connection, rd, connection.Command.CommandText);
var isFaulted = false;
do
{
T result;
try
{
result = objectReader(rd);
}
catch (InvalidCastException)
{
if (isFaulted)
{
throw;
}
isFaulted = true;
objectReader = GetObjectReader2 <T>(connection, rd, connection.Command.CommandText);
result = objectReader(rd);
}
yield return(result);
} while (rd.Read());
}
}
}
public static DataTable LoadDataTable(this DataConnection dc, string sql)
{
var dt = new DataTable();
dt.Load(dc.ExecuteReader(sql).Reader);
return(dt);
}
public static DataReader ExecuteReader(this DataConnection connection, string sql)
{
connection.SetCommand(sql);
return(new DataReader {
Connection = connection, Reader = connection.ExecuteReader()
});
}
public static DataReader ExecuteReader(this DataConnection connection, string sql, params DataParameter[] parameters)
{
connection.SetCommand(sql);
SetParameters(connection, parameters);
return(new DataReader {
Connection = connection, Reader = connection.ExecuteReader()
});
}
public static IEnumerable <T> Query <T>(this DataConnection connection, Func <IDataReader, T> objectReader, string sql)
{
connection.SetCommand(sql);
using (var rd = connection.ExecuteReader())
while (rd.Read())
{
yield return(objectReader(rd));
}
}
public static IEnumerable <T> QueryProc <T>(this DataConnection connection, Func <IDataReader, T> objectReader, string sql, params DataParameter[] parameters)
{
connection.SetCommand(sql);
connection.Command.CommandType = CommandType.StoredProcedure;
SetParameters(connection, parameters);
using (var rd = connection.ExecuteReader())
while (rd.Read())
{
yield return(objectReader(rd));
}
}
public static IEnumerable <T> Query <T>(this DataConnection connection, Func <IDataReader, T> objectReader, string sql, object parameters)
{
connection.SetCommand(sql);
var dps = GetDataParameters(connection, parameters);
SetParameters(connection, dps);
using (var rd = connection.ExecuteReader())
while (rd.Read())
{
yield return(objectReader(rd));
}
}
public override IDataReader ExecuteReader()
{
SetCommand(true);
_dataConnection.InitCommand(CommandType.Text, _preparedQuery.Commands[0], null, QueryHints);
if (_preparedQuery.Parameters != null)
{
foreach (var p in _preparedQuery.Parameters)
{
_dataConnection.Command.Parameters.Add(p);
}
}
return(_dataConnection.ExecuteReader());
}
public static IDataReader ExecuteReader(DataConnection dataConnection, IQueryContext context)
{
var preparedQuery = GetCommand(dataConnection, context);
GetParameters(dataConnection, context, preparedQuery);
dataConnection.InitCommand(CommandType.Text, preparedQuery.Commands[0], null, preparedQuery.QueryHints);
if (preparedQuery.Parameters != null)
{
foreach (var p in preparedQuery.Parameters)
{
dataConnection.Command.Parameters.Add(p);
}
}
return(dataConnection.ExecuteReader());
}
public void TestDataReader(string context)
{
using (var conn = new DataConnection(context))
using (var reader = conn.ExecuteReader("SELECT 1; SELECT '2'"))
{
var n = reader.Execute<int>();
Assert.AreEqual(1, n);
var s = reader.Query<string>();
Assert.AreEqual("2", s.First());
}
}
