Executing a Query

Using Static Statements

1. Get a statement object.

   Statement st = db.createStatement();

2. Get a result set object.

   ResultSet rs = st.executeQuery(<query>);

   <query> is any standard SQL query (SELECT command)

3. Get the result set metadata.

   ResultSetMetaData rsmeta = rs.getMetaData();

4. Use a standard forward only ResultSet cursor

   while(rs.next())

   {

   ...

   }

5. Close objects.

   rs.close();

   st.close();

   db.close();

Using Prepared Statements

+ START OF MATERIAL FROM RELEASE NOTES

The following functionality is now supported in the JDBC driver:

• When you call prepareStatement() with a string containing an SQL statement, the driver sends it to the server and stores the statement identifier for later execution. The string is stored on the server and thus is not sent again when the prepared statement is executed more than once.
• When you call any of the following methods, the driver binds the statement parameters but does not communicate with the server:

  setNull(), setInt(), setLong(), setString(), setBoolean(), setDouble(), setFloat(), setDate(), setTime(), setTimestamp()

• When you call execute(), executeQuery(), or executeUpdate(), the driver sends the statement identifier and parameter values to the server and returns a result set or an error. The driver also returns semantic and syntactic errors at this point.

JDBC Example

PreparedStatement pst = dbconn.prepareStatement(

"select * from fact where type=?");

pst.setString(1, "trades");

ResultSet rs = pst.executeQuery();

JDBCSetupTest.printResults(rs, resultStream);

- END OF MATERIAL FROM RELEASE NOTES