Fix data types for 'COLUMNS' schema. Fixes #802

This brings MySqlConnector in line with Connector/NET's schema for this DataTable.

Author: bgrainger

src/MySqlConnector/Core/SchemaProvider.cs

@@ -169,29 +169,32 @@ private void FillColumns(DataTable dataTable)
 				new DataColumn("TABLE_SCHEMA", typeof(string)), // lgtm[cs/local-not-disposed]
 				new DataColumn("TABLE_NAME", typeof(string)), // lgtm[cs/local-not-disposed]
 				new DataColumn("COLUMN_NAME", typeof(string)), // lgtm[cs/local-not-disposed]
-				new DataColumn("ORDINAL_POSITION", typeof(int)), // lgtm[cs/local-not-disposed]
+				new DataColumn("ORDINAL_POSITION", typeof(uint)), // lgtm[cs/local-not-disposed]
 				new DataColumn("COLUMN_DEFAULT", typeof(string)), // lgtm[cs/local-not-disposed]
 				new DataColumn("IS_NULLABLE", typeof(string)), // lgtm[cs/local-not-disposed]
 				new DataColumn("DATA_TYPE", typeof(string)), // lgtm[cs/local-not-disposed]
-				new DataColumn("CHARACTER_MAXIMUM_LENGTH", typeof(int)), // lgtm[cs/local-not-disposed]
-				new DataColumn("CHARACTER_OCTET_LENGTH", typeof(int)), // lgtm[cs/local-not-disposed]
-				new DataColumn("NUMERIC_PRECISION", typeof(int)), // lgtm[cs/local-not-disposed]
-				new DataColumn("NUMERIC_SCALE", typeof(int)), // lgtm[cs/local-not-disposed]
-				new DataColumn("DATETIME_PRECISION", typeof(int)), // lgtm[cs/local-not-disposed]
+				new DataColumn("CHARACTER_MAXIMUM_LENGTH", typeof(long)), // lgtm[cs/local-not-disposed]
+				new DataColumn("NUMERIC_PRECISION", typeof(ulong)), // lgtm[cs/local-not-disposed]
+				new DataColumn("NUMERIC_SCALE", typeof(ulong)), // lgtm[cs/local-not-disposed]
+				new DataColumn("DATETIME_PRECISION", typeof(uint)), // lgtm[cs/local-not-disposed]
 				new DataColumn("CHARACTER_SET_NAME", typeof(string)), // lgtm[cs/local-not-disposed]
 				new DataColumn("COLLATION_NAME", typeof(string)), // lgtm[cs/local-not-disposed]
-				new DataColumn("COLUMN_TYPE", typeof(string)), // lgtm[cs/local-not-disposed]
 				new DataColumn("COLUMN_KEY", typeof(string)), // lgtm[cs/local-not-disposed]
 				new DataColumn("EXTRA", typeof(string)), // lgtm[cs/local-not-disposed]
 				new DataColumn("PRIVILEGES", typeof(string)), // lgtm[cs/local-not-disposed]
 				new DataColumn("COLUMN_COMMENT", typeof(string)), // lgtm[cs/local-not-disposed]
-				new DataColumn("GENERATION_EXPRESSION", typeof(string)), // lgtm[cs/local-not-disposed]
 			});
 
+			using (var command = new MySqlCommand("SELECT 1 FROM INFORMATION_SCHEMA.COLUMNS WHERE table_schema = 'information_schema' AND table_name = 'COLUMNS' AND column_name = 'GENERATION_EXPRESSION';", m_connection))
+			{
+				if (command.ExecuteScalar() is object)
+					dataTable.Columns.Add(new DataColumn("GENERATION_EXPRESSION", typeof(string))); // lgtm[cs/local-not-disposed]
+			}
+
 			using (var command = new MySqlCommand("SELECT 1 FROM INFORMATION_SCHEMA.COLUMNS WHERE table_schema = 'information_schema' AND table_name = 'COLUMNS' AND column_name = 'SRS_ID';", m_connection))
 			{
 				if (command.ExecuteScalar() is object)
-					dataTable.Columns.Add(new DataColumn("SRS_ID", typeof(string))); // lgtm[cs/local-not-disposed]
+					dataTable.Columns.Add(new DataColumn("SRS_ID", typeof(uint))); // lgtm[cs/local-not-disposed]
 			}
 
 			FillDataTable(dataTable, "COLUMNS");

tests/SideBySide/SchemaProviderTests.cs

@@ -40,6 +40,47 @@ public void ReservedWordsSchema()
 #endif
 		}
 
+		[Fact]
+		public void ColumnsSchema()
+		{
+			var table = m_database.Connection.GetSchema("Columns");
+			Assert.NotNull(table);
+			AssertHasColumn("TABLE_CATALOG", typeof(string));
+			AssertHasColumn("TABLE_SCHEMA", typeof(string));
+			AssertHasColumn("TABLE_NAME", typeof(string));
+			AssertHasColumn("COLUMN_NAME", typeof(string));
+			AssertHasColumn("ORDINAL_POSITION", typeof(uint));
+			AssertHasColumn("COLUMN_DEFAULT", typeof(string));
+			AssertHasColumn("IS_NULLABLE", typeof(string));
+			AssertHasColumn("DATA_TYPE", typeof(string));
+			AssertHasColumn("CHARACTER_MAXIMUM_LENGTH", typeof(long));
+			AssertHasColumn("NUMERIC_PRECISION", typeof(ulong));
+			AssertHasColumn("NUMERIC_SCALE", typeof(ulong));
+			AssertHasColumn("DATETIME_PRECISION", typeof(uint));
+			AssertHasColumn("CHARACTER_SET_NAME", typeof(string));
+			AssertHasColumn("COLLATION_NAME", typeof(string));
+			AssertHasColumn("COLUMN_KEY", typeof(string));
+			AssertHasColumn("EXTRA", typeof(string));
+			AssertHasColumn("PRIVILEGES", typeof(string));
+			AssertHasColumn("COLUMN_COMMENT", typeof(string));
+
+			void AssertHasColumn(string name, Type type)
+			{
+				var column = table.Columns[name];
+				Assert.NotNull(column);
+
+				// allow integral types with a larger positive range
+				if (type == typeof(int))
+					Assert.True(type == typeof(int) || type == typeof(uint) || type == typeof(long) || type == typeof(ulong));
+				else if (type == typeof(uint))
+					Assert.True(type == typeof(uint) || type == typeof(long) || type == typeof(ulong));
+				else if (type == typeof(long))
+					Assert.True(type == typeof(long) || type == typeof(ulong));
+				else
+					Assert.Equal(type, column.DataType);
+			}
+		}
+
 		readonly DatabaseFixture m_database;
 	}
 }