Tutorials on access the Database for data

[Former Member]

Hello,

I wanted few good tutorials, on how do retrieve data from the database or info cubes of BI using the webdynpro technology.

Thanks,

karthik

[Former Member]

Hi,

Thanks Roberto Tagliento for the code what you had send. I have also award points for it. But id you can suggest me tutorial examples, where i can get from SDN. tut on picking up data from infocubes BI concept . mostly with DB and other good examples.

Thanks,

karthik

[roberto_tagliento]

Sample of connection to a DB

		public static Connection startDBCon(String datasource_name){
		
		 DataSource ds;
		 InitialContext ctx;
		 Properties properties;
		 
	  try {
		  datasource_name = "jdbc/" + datasource_name; // + "DB";
		  String contextUrl = "";
		  String contextFactory = "com.sap.engine.services.jndi.InitialContextFactoryImpl";
		  properties = new Properties();
		  properties.put("java.naming.factory.initial", contextFactory);

		  ctx = new InitialContext(properties);
		  ds = (DataSource)ctx.lookup(datasource_name);
		  return ds.getConnection();
		
	  } catch (Exception e) {
//		  e.printStackTrace();
	  }
	  
	  return null;
  		
	}

usually datasource_name is equal to:

			  datasource_name = 
						  "SAP" + 
						  (String) System.getProperties().get("SAPSYSTEMNAME")
								  + "DB";

or

datasource_name = "SAPSR3DB";

by the way have to call you system administrator and ask, this datasourcename is configurated under Visual Adminstrator.

Here some SQL call after got connection:

	public Rows[] findByDynamicSelect(String sql, Object[] sqlParams) throws YourException
	{
		// declare variables
		final boolean isConnSupplied = (userConn != null);
		Connection conn = null;
		PreparedStatement stmt = null;
		ResultSet rs = null;
		
		try {
			// get the user-specified connection or get a connection from the ResourceManager
			conn = isConnSupplied ? userConn : ResourceManager.getConnection();
		
			// construct the SQL statement
			final String SQL = sql;
		
		
			// prepare statement
			stmt = conn.prepareStatement( SQL );

			// bind parameters
			for (int i=0; sqlParams!=null && i<sqlParams.length; i++ ) {
				stmt.setObject( i+1, sqlParams<i> );
			}
		
		
			rs = stmt.executeQuery();
		
			// fetch the results
			return fetchMultiResults(rs);
		}
		catch (SQLException _e) {
			throw new YourException"SQLException: " + _e.getMessage(), _e );
		}
		catch (Exception _e) {
			throw new YourException"Exception: " + _e.getMessage(), _e );
		}
		finally {
			ResourceManager.close(rs);
			ResourceManager.close(stmt);
			if (!isConnSupplied) {
				ResourceManager.close(conn);
			}
		
		}
		
	}

example how to call:

	public Row findByPrimaryKey(String Par1, int Par2, int Par3) throws YourException
	{
		Row ret[] = findByDynamicSelect( SQL_SELECT + " WHERE Par1 = ? AND Par2 = ? AND Par3 = ? ", new Object[] { Par1, new Integer(Par2),  new Integer(Par3) } );
		return ret.length==0 ? null : ret[0];
	}

after for Row (Resultset) there are method like:

Row.getInt( COLUMN_FIELD )

Row.getString( COLUMN_FIELD )

Row.getDouble( COLUMN_FIELD )