How can we use MS Acces database.. in c#?

For connection you can use OledbConnection class as follows:

//connection string

string connstr= "Provider=Microsoft.Jet.OLEDB.4.0; Data Source=path_to_accessfile.mdb"

OledbConnection con=new OledbConnection(connstr);

//opening connection

con.open();

//closing connection

con.close();

For command object you can use OledbCommand class as follows:

//oledbcommand object

OledbCommand com=new OledbCommand();

//setting connection

com.connection=con;

com.CommandText="select or insert or update query you want to perform";

com.CommandType=CommandType.StoredProcedure or CommandType.Text or CommandType.TableDirect;

//to execute on query statements such as insert and update use the following method after supplying command text

com.ExecuteNonquery();

to return result set and store it.

For that you have OledbDataAdapter,DataSet and DataTable classes.

OledbDataAdapter da=new OledbDataAdapter();

da.selectCommand=com;

//or alternatively you can do this

OledbDataAdapter da =new OledbDataAdapter("select query","connection string");

//To declare dataset

Dataset ds=new Dataset();

//To declare datatable

Datatable dt=new DataTable();

//to fill dataset with data

da.fill(ds,"table name");

//to fill datatable with data

da.fill(dt,"table name");

Basically dataset is the collection of datatables and other collections.

To access a particular table you can have it as follows:

dt=ds.tables["table name" or table index];

//All data returned in datatable are arranged in spreadsheet way.

//To access a particular row.

DataRow dr=dt.rows[index];

To access a particular row and column data

string col1=dt.rows[0]["column name" or column index].toString();

Generally speaking Dataset and DataTables are disconnected objects. Means it acts as logical structure of your database. So you can add rows or columns into the table and map them later back into the database. As they act as offline database they consume some space in your memory.

If you don't want consume space then you can use another object called OledbDataReader as follows.

OledbDataReader dr=com.ExecuteReader();

This is all I can give you right now. For detail please look into various materials provided online or goto msdn site.