JDBC FAQ Part8

16:Ingeneral execute() method can be used to execute selection group SQl queries for getting the data from Database , but execute() return a boolean value true so here how it possible to fetch the data from database?

• Execute() can be used to execute both selection group sql query and updation group sql query.
• If we use execute() to execute a selection group sql query then DBE(Database engine) will execute that sql query and  send back the fetched data from database to java application. Now java application will prepare a ResultSet object with the fetched data but execute() will return “true” as a Boolean value.
• At this situation to get the reference of the ResultSet object explicitily, we will use the following method from Statement object.

                        public ResultSet getResultSet()

            Eg:  boolean b = st.execute(“select * from emp1”);
                    System.out.println(b);
                    ResultSet rs = st.getResultSet();

17:Ingeneral execute() method can be used to execute updatation group SQl queries for updating the data on Database , but execute() return a boolean value false  so here how it possible to get the records updated count value(int value)?

• Execute() can be used to execute both selection group sql queries and updation group sql queries.

• If we use execute() to execute an updation group sql query then DBE will execute it and send back the records updated count value to the java application. But execute() will return “false” as a Boolean value. At this instance, to get the records updated count value explicitly we will use the following method from Statement object.

                        public int getUpdateCount()

            Eg:      import java.sql.*;
                        public class FetchEx
                        {
                                    public static void main(String[] args)throws Exception
                                    {
                                                Class.forName(“sun.jdbc.odbc.JdbcOdbcDriver”);

Connection con = DriverMadoeer.getConnection(“jdbc:odbc:doe”,”system”,”jhon”);

                                                Statement st = con.createStatement();
boolean b = st.execute(“update emp1 set esal=esal+500 where esal<9000”);
System.out.println(b);
int updateCount = st.getUpdateCount();j
System.out.println(updateCount);
                                    }
                        }