How can i read database from database row by row?

i need to select from database row by row this database built on appserve.

i need to read first row then second but i can't I try a lot . when i select all from database .all field are shown but i need to select row by row ,

also I can't get the true size of database by this function

size('my database name')

or

length('my database name')

I write in my code by using size of database

for i=1:c
    for j=1:r

output=x(j,i)

%out=x(i,1)

      end
  end

cell2mat(x)
x(2,2)
%

[Geoff]

Why do you want to read one row at a time? What is wrong with selecting all rows at once? You haven't shown the database query that you are using.

[Eman Shaltout]

I select all row and put result in variable but I need to search by row.....

QUERY = 'SELECT Feature , Feature2 , Feature3 FROM members '

[x]=fetch(dbConn,QUERY)

Answer 1

[Juan B. Gutierrez]

Dear Eman, let me start by saying that you can access any relational database from MATLAB using many tools, including the Database toolbox, and the .NET and/or Java libraries.

The following example uses .NET data objects to connect to a MySQL database (you can connect with this method to ANY database; simply use the correct connection string), send a query, read row by row, and then load dataset columns into MATLAB variables. It is an expandeded version of the solution found at http://stackoverflow.com/questions/6593485/how-to-connect-to-microsoft-sql-server-2008-mssql-from-matlab. I hope this helps.

     try  
          % Database conectivity parameters
          host = '192.168.1.3'; % Insert your server's IP here
          port = '3306'; % Default port for MySQL
          user = 'yourUserName'; 
          password = 'youUserPWD';
          dbName = 'yourDatabase';
          connString = ['Server=' host ';Port=' port ';Database=' dbName ...
                     ';Uid=' user ';Pwd=' password ...
                     ';Driver={MySQL ODBC 5.1 Driver};Option=3;'];

          % Generate SQL query based upon input 
          sSQL =  ['select * from table where' variableWithSQLConditions]; 
          sSQL = char(sSQL);

          % Connect to the database
          var1 = []; var2 = []; var3=[];
          NET.addAssembly('System.Data');
          import System.Data.*
          conn = Odbc.OdbcConnection(connString);
          conn.Open();
          dr = Odbc.OdbcCommand(sSQL, conn);

          % Retrieve a record at a time 
          r = dr.ExecuteReader();
          while r.Read()
              var1 = [var1; str2double(char(r.GetString(0)))];
              var2 = [var2 ; str2double(char(r.GetString(1)))];
              var3 = [var3 ; str2double(char(r.GetString(2)))];
          end

          % Close connection
          r.Close()
          conn.Close()

      catch err
          cVars = err.message;
      end