有关数组的 C# 错误(对象引用未设置为对象的实例

错误图像 https://i.stack.imgur.com/AC5sE.png

我想将数据添加到 Dataz，但在构建时发现错误

这是我的代码

int i = 0;
string[][,] dataz = null;
conn.Open();
OleDbCommand db = conn.CreateCommand();
db.CommandType = CommandType.Text;
db.CommandText = "select name,img from [building] order by id asc ";
OleDbDataReader oReader = db.ExecuteReader();

while (oReader.Read())
{
        string name = oReader.GetString(0);
        string img = oReader.GetString(1);
        dataz[i] = new string[,] { { "name", name }, { "img", img } };
        i++;
}
conn.Close();

var data = 
    ctx.Buildings.OrderBy(x => x.id).Select(x => new { x.name, x.img }).ToArray();