Merge pull request #1522 from AlexKerman/master

Make table alias accessible from MySqlDbColumn.

Author: bgrainger

src/MySqlConnector/MySqlDbColumn.cs

@@ -48,7 +48,13 @@ internal MySqlDbColumn(int ordinal, ColumnDefinitionPayload column, bool allowZe
 		}
 		NumericScale = column.Decimals;
 		ProviderType = mySqlDbType;
+		TableName = column.Table;
 	}
 
 	public MySqlDbType ProviderType { get; }
+
+	/// <summary>
+	/// Gets the name of the table that the column belongs to. This will be the alias if the table is aliased in the query.
+	/// </summary>
+	public string TableName { get; }
 }

tests/IntegrationTests/QueryTests.cs

@@ -933,6 +933,48 @@ public void GetColumnSchemaAfterNextResult()
 		Assert.False(reader.NextResult());
 		Assert.Empty(reader.GetColumnSchema());
 	}
+
+	[Fact]
+	public void GetColumnSchemaForTableAlias()
+	{
+		using var cmd = m_database.Connection.CreateCommand();
+		cmd.CommandText = """
+			drop table if exists column_schema_table2;
+			drop table if exists column_schema_table1;
+			create table column_schema_table1(id int not null primary key);
+			create table column_schema_table2(id int not null primary key,
+				table1_id1 int not null,
+				table1_id2 int not null,
+				foreign key (table1_id1) references column_schema_table1(id),
+				foreign key (table1_id2) references column_schema_table1(id));
+			insert into column_schema_table1(id) values(1),(2);
+			insert into column_schema_table2(id, table1_id1, table1_id2) values(3, 1, 2);
+			""";
+		cmd.ExecuteNonQuery();
+
+		cmd.CommandText = """
+			select t2.id as id2, t1a.id as ida, t1b.id as idb
+			from column_schema_table2 t2
+			join column_schema_table1 t1a on t2.table1_id1 = t1a.id
+			join column_schema_table1 t1b on t2.table1_id2 = t1b.id;
+			""";
+		using var reader = cmd.ExecuteReader();
+		Assert.True(reader.Read());
+		var schema = reader.GetColumnSchema();
+		Assert.Equal(3, schema.Count);
+		Assert.Equal("id2", schema[0].ColumnName);
+		Assert.Equal("ida", schema[1].ColumnName);
+		Assert.Equal("idb", schema[2].ColumnName);
+		Assert.Equal("id", schema[0].BaseColumnName);
+		Assert.Equal("id", schema[1].BaseColumnName);
+		Assert.Equal("id", schema[2].BaseColumnName);
+		Assert.Equal("column_schema_table2", schema[0].BaseTableName);
+		Assert.Equal("column_schema_table1", schema[1].BaseTableName);
+		Assert.Equal("column_schema_table1", schema[2].BaseTableName);
+		Assert.Equal("t2", ((MySqlDbColumn) schema[0]).TableName);
+		Assert.Equal("t1a", ((MySqlDbColumn) schema[1]).TableName);
+		Assert.Equal("t1b", ((MySqlDbColumn) schema[2]).TableName);
+	}
 #endif
 
 	private void UseReaderWithoutDisposingThread(object obj)