Set object properties via a loop?

I have a data container object that holds user info, with one public property mapping to each field in my database table.

When retrieving a user's info from my db I'm using a DataReader, and writing code like this:

myDBObj.name = reader["name"];
myDBObj.id = reader["id"];

Etc, etc. This works ok, but I was hoping to use the DataReader's GetName and FieldCount methods to automate setting my property values.

Something like:

for (int i = 0; i <= reader.FieldCount; i++)
{
string fieldName = reader.GetName(i);
usr.[fieldName] = (reader.GetDataTypeName(i))reader[i];
}

The part in bold is throwing me--is there a way to use a variable in determining which property I'm assigning? Is there another way to do what I'm trying?

Thanks!

Aaron

You could try reader[i].ToString()

usr.[fieldName] = reader[i].ToString();

Sample Code:

SqlConnection connection = new SqlConnection(ConnectionString);
SqlCommand commond = new SqlCommand("SELECT * FROM TEST");
DataSet fillDataSet = new DataSet();
commond.Connection = connection;
commond.CommandType = CommandType.Text;
connection.Open();
SqlDataReader dr;
dr = commond.ExecuteReader();
while(dr.Read())
{
for(int i=0; i<dr.FieldCount;i++)
{
Response.Write(dr.GetName(i) + ":"+ i.ToString() +":" + dr[i].ToString());
Response.Write("<br>");
}
}
connection.Close();

Obtaining the info via the datareader isn't the problem, the issue is that the object I'm creating (objUserDetail) has properties of varying types (strings, ints, datetimes, etc).

While I could certainly simply write out a long list of property assignments and cast the datareader's info in the correct type each time, I'd much rather figure out a way to do it via a loop.

I figured out how to use a PropertyInfo object to get the names of the properties dynamically at runtime, but now the problem is the datareader is sending all the data back as a string, and I can't find a way to convert/cast it into the format the various properties are expecting.

Normally I would do this:

objUserDetail.UserID = (int)reader["UserID"];

But I need a way to convert the reader's field value dynamically.

Anyone know how?

Can you try this..

(dr[i].GetType()) dr[i].ToString()

while(dr.Read())
{
for(int i=0; i<dr.FieldCount;i++)
{
Response.Write(dr.GetName(i) + ":"+ dr[i].GetType() +":" + dr[i].ToString());
Response.Write("<br>");
}
}

Why don't you use TypeDataSet?

like this:

Dim myDBobjAs New usrDim fieldNameAs String Dim flagsAs BindingFlags = BindingFlags.InstanceOr BindingFlags.Public Or BindingFlags.IgnoreCaseOr BindingFlags.Static Or BindingFlags.FlattenHierarchyDim pAs PropertyInfoDim readerAs System.Data.SqlClient.SqlDataReader = GetTheReader()'populate one entityFor iAs Integer = 0To (reader.FieldCount - 1) fieldname = reader.GetName(i) p =GetType(usr).GetProperty(fieldName, flags) p.SetValue(myDBobj, reader(i),Nothing)Next

Thanks for your help, everyone!

I was able to get it working, and now I'm reconsidering the whole data table class concept, since that's what DataSets are for, right?

aaron

DataSets are basically just collections of DataTables.

NC...