Allow GetOrdinal before Read. Fixes #379

Author: bgrainger

src/MySqlConnector/MySqlClient/MySqlDataReader.cs

@@ -171,7 +171,7 @@ private async Task<ResultSet> ScanResultSetAsyncAwaited(IOBehavior ioBehavior, R
 		public override bool IsClosed => Command == null;
 		public override int RecordsAffected => m_recordsAffected;
 
-		public override int GetOrdinal(string name) => GetResultSet().GetCurrentRow().GetOrdinal(name);
+		public override int GetOrdinal(string name) => GetResultSet().GetOrdinal(name);
 
 		public override bool GetBoolean(int ordinal) => GetResultSet().GetCurrentRow().GetBoolean(ordinal);
 

src/MySqlConnector/MySqlClient/Results/ResultSet.cs

@@ -301,6 +301,20 @@ public bool HasRows
 			}
 		}
 
+		public int GetOrdinal(string name)
+		{
+			if (name == null)
+				throw new ArgumentNullException(nameof(name));
+
+			for (var column = 0; column < ColumnDefinitions.Length; column++)
+			{
+				if (name.Equals(ColumnDefinitions[column].Name, StringComparison.OrdinalIgnoreCase))
+					return column;
+			}
+
+			throw new IndexOutOfRangeException("The column name '{0}' does not exist in the result set.".FormatInvariant(name));
+		}
+
 		public Row GetCurrentRow()
 		{
 			if (State != ResultSetState.ReadingRows)

src/MySqlConnector/MySqlClient/Results/Row.cs

@@ -1,5 +1,4 @@
 using System;
-using System.Buffers;
 using System.Globalization;
 using System.Text;
 using MySql.Data.Serialization;
@@ -232,19 +231,7 @@ public int GetValues(object[] values)
 
 		public object this[int ordinal] => GetValue(ordinal);
 
-		public object this[string name] => GetValue(GetOrdinal(name));
-
-		public int GetOrdinal(string name)
-		{
-			for (int column = 0; column < ResultSet.ColumnDefinitions.Length; column++)
-			{
-				if (ResultSet.ColumnDefinitions[column].Name.Equals(name, StringComparison.OrdinalIgnoreCase))
-					return column;
-			}
-
-			// TODO: Correct exception
-			throw new IndexOutOfRangeException("The column name '{0}' does not exist in the result set.".FormatInvariant(name));
-		}
+		public object this[string name] => GetValue(ResultSet.GetOrdinal(name));
 
 		public object GetValue(int ordinal)
 		{

tests/SideBySide/QueryTests.cs

@@ -23,6 +23,77 @@ public void Dispose()
 			m_database.Connection.Close();
 		}
 
+		[Fact]
+		public void GetOrdinal()
+		{
+			using (var cmd = m_database.Connection.CreateCommand())
+			{
+				cmd.CommandText = "select 0 as zero, 1 as one;";
+				using (var reader = cmd.ExecuteReader())
+				{
+					Assert.Equal(0, reader.GetOrdinal("zero"));
+					Assert.Equal(1, reader.GetOrdinal("one"));
+				}
+			}
+		}
+
+		[Fact]
+		public void GetOrdinalIgnoreCase()
+		{
+			using (var cmd = m_database.Connection.CreateCommand())
+			{
+				cmd.CommandText = "select 0 as zero, 1 as one;";
+				using (var reader = cmd.ExecuteReader())
+				{
+					Assert.Equal(0, reader.GetOrdinal("Zero"));
+					Assert.Equal(1, reader.GetOrdinal("ONE"));
+				}
+			}
+		}
+
+		[Fact]
+		public void GetOrdinalExceptionForNoColumn()
+		{
+			using (var cmd = m_database.Connection.CreateCommand())
+			{
+				cmd.CommandText = "select 0 as zero, 1 as one;";
+				using (var reader = cmd.ExecuteReader())
+				{
+					Assert.Throws<IndexOutOfRangeException>(() => reader.GetOrdinal("three"));
+				}
+			}
+		}
+
+		[Fact]
+		public void GetOrdinalExceptionForNull()
+		{
+			using (var cmd = m_database.Connection.CreateCommand())
+			{
+				cmd.CommandText = "select 0 as zero, 1 as one;";
+				using (var reader = cmd.ExecuteReader())
+				{
+					Assert.Throws<ArgumentNullException>(() => reader.GetOrdinal(null));
+				}
+			}
+		}
+
+		[Fact]
+		public void GetOrdinalBeforeAndAfterRead()
+		{
+			using (var cmd = m_database.Connection.CreateCommand())
+			{
+				cmd.CommandText = "select 0 as zero, 1 as one;";
+				using (var reader = cmd.ExecuteReader())
+				{
+					Assert.Equal(1, reader.GetOrdinal("one"));
+					Assert.True(reader.Read());
+					Assert.Equal(1, reader.GetOrdinal("one"));
+					Assert.False(reader.Read());
+					Assert.Equal(1, reader.GetOrdinal("one"));
+				}
+			}
+		}
+
 		[Fact]
 		public void WithoutUserVariables()
 		{