Microsoft.Data.Sqlite: Enable GetFieldValue<Stream>() and TextReader

Part of #19991
dotnet · Dec 8, 2020 · 82847c7 · 82847c7
1 parent fc43d5a
commit 82847c7
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Showing 3 changed files with 62 additions and 4 deletions.
diff --git a/src/Microsoft.Data.Sqlite.Core/SqliteDataReader.cs b/src/Microsoft.Data.Sqlite.Core/SqliteDataReader.cs
@@ -551,9 +551,11 @@ public override Stream GetStream(int ordinal)
         /// <param name="ordinal">The zero-based column ordinal.</param>
         /// <returns>The returned object.</returns>
         public override TextReader GetTextReader(int ordinal)
-            => IsDBNull(ordinal)
-                ? (TextReader)new StringReader(string.Empty)
-                : new StreamReader(GetStream(ordinal), Encoding.UTF8);
+            => _closed
+                ? throw new InvalidOperationException(Resources.DataReaderClosed(nameof(GetTextReader)))
+                : _record == null
+                    ? throw new InvalidOperationException(Resources.NoData)
+                    : _record.GetTextReader(ordinal);
 
         /// <summary>
         ///     Gets the value of the specified column.

diff --git a/src/Microsoft.Data.Sqlite.Core/SqliteDataRecord.cs b/src/Microsoft.Data.Sqlite.Core/SqliteDataRecord.cs
@@ -60,7 +60,19 @@ protected override string GetStringCore(int ordinal)
             => sqlite3_column_text(Handle, ordinal).utf8_to_string();
 
         public override T GetFieldValue<T>(int ordinal)
-            => base.GetFieldValue<T>(ordinal)!;
+        {
+            if (typeof(T) == typeof(Stream))
+            {
+                return (T)(object)GetStream(ordinal);
+            }
+
+            if (typeof(T) == typeof(TextReader))
+            {
+                return (T)(object)GetTextReader(ordinal);
+            }
+
+            return base.GetFieldValue<T>(ordinal)!;
+        }
 
         protected override byte[] GetBlob(int ordinal)
             => base.GetBlob(ordinal)!;
@@ -317,6 +329,11 @@ public virtual Stream GetStream(int ordinal)
             return new SqliteBlob(_connection, blobDatabaseName, blobTableName, blobColumnName, rowid, readOnly: true);
         }
 
+        public virtual TextReader GetTextReader(int ordinal)
+            => IsDBNull(ordinal)
+                ? new StringReader(string.Empty)
+                : new StreamReader(GetStream(ordinal), Encoding.UTF8);
+
         public bool Read()
         {
             if (!_stepped)

diff --git a/test/Microsoft.Data.Sqlite.Tests/SqliteDataReaderTest.cs b/test/Microsoft.Data.Sqlite.Tests/SqliteDataReaderTest.cs
@@ -852,6 +852,45 @@ public void GetFieldValue_of_Nullable_works()
                 "SELECT 1;",
                 (int?)1);
 
+        [Fact]
+        public void GetFieldValue_of_Stream_works()
+        {
+            using (var connection = new SqliteConnection("Data Source=:memory:"))
+            {
+                connection.Open();
+
+                using (var reader = connection.ExecuteReader("SELECT x'7E57';"))
+                {
+                    var hasData = reader.Read();
+                    Assert.True(hasData);
+
+                    var stream = reader.GetFieldValue<Stream>(0);
+                    Assert.Equal(0x7E, stream.ReadByte());
+                    Assert.Equal(0x57, stream.ReadByte());
+                }
+            }
+        }
+
+        [Fact]
+        public void GetFieldValue_of_TextReader_works()
+        {
+            using (var connection = new SqliteConnection("Data Source=:memory:"))
+            {
+                connection.Open();
+
+                using (var reader = connection.ExecuteReader("SELECT 'test';"))
+                {
+                    var hasData = reader.Read();
+                    Assert.True(hasData);
+
+                    using (var textReader = reader.GetFieldValue<TextReader>(0))
+                    {
+                        Assert.Equal("test", textReader.ReadToEnd());
+                    }
+                }
+            }
+        }
+
         [Fact]
         public void GetFieldValue_of_TimeSpan_works()
             => GetFieldValue_works(