Why the data inserted two times into the DB?

Question

Hai all,
When I press the submit button in my form the data will be inserted two timesinto DB. Please help me.
import java.sql.Connection; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.SQLException; import com.vguss.bean.RegisterInfoBean; import com.vguss.helper.Out; public class InsertRegInfo { public static Connection connection = DBConnection.getDBConnection(); public static void insertRegData(RegisterInfoBean bean) { Connection connection = DBConnection.getDBConnection(); String loginID = bean.getLoginId(); try { PreparedStatement pst = connection .prepareStatement("SELECT login_id FROM login_details WHERE login_id = ?"); pst.setString(1, loginID); ResultSet set = pst.executeQuery(); if (!set.next()) { insertData(bean); } } catch (SQLException e1) { e1.printStackTrace(); } } private static void insertData(RegisterInfoBean bean) { try { PreparedStatement ps = connection .prepareStatement("INSERT INTO login_details (login_id, password, profile_created_by, security_question, answer, full_name, receive_sms, show_details, agree_terms, register_on) VALUES (?,?,?,?,?,?,?,?,?,now())"); ps.setString(1, bean.getLoginId()); ps.setString(2, bean.getPassword()); ps.setString(3, bean.getProf_created_by()); ps.setString(4, bean.getSecurity_Question()); ps.setString(5, bean.getAnswer()); ps.setString(6, bean.getFullName()); ps.setString(7, bean.getLikeSMS()); ps.setString(8, bean.getShowDetails()); ps.setString(9, bean.getAgreeToTerms()); ps.executeUpdate(); PreparedStatement pstmt = connection .prepareStatement("INSERT INTO user_profile (login_id, gender, email, date_of_birth) VALUES (?, ?, ?, ?)"); pstmt.setString(1, bean.getLoginId()); pstmt.setString(2, bean.getGender()); pstmt.setString(3, bean.getEmailID()); pstmt.setString(4, bean.getDateOfBirth()); pstmt.executeUpdate(); /* insert login id to preferred_partner table */ PreparedStatement pStmt = connection .prepareStatement("INSERT INTO preferred_partner (login_id) VALUES(?)"); pStmt.setString(1, bean.getLoginId()); pStmt.executeUpdate(); } catch (SQLException e) { Out.err(e); } } }

Answer 1

The most obvious thought is that you have a duplicate login id.
You're trying, but I would not consider this to be well written code, for these reasons:
1. You don't close any JDBC resources in finally blocks - no connections, no statements, no result sets. Search the forum for people with "max open cursors exceeded" to see why this is a bad idea.
2. You create a static Connection in this class, but nobody closes it. Classes that execute SQL should not be responsible for obtaining connections; a Connection should be provided to them. Transactions are the reason: a class executing SQL can't know if it's involved in a unit of work with other classes. Somebody who knows the use case and the transaction boundaries ought to be getting the Connection, handling commit/rollback, and closing the Connection.
3. Refactor that INSERT into three methods. You'll be glad you did someday.
4. Your INSERT method looks like it's doing a security check, too. Isn't it a little late for that? If you must, move that code into a separate method that returns a boolean. A well-designed method does one thing well. Yours is doing two.
5. The common JDBC idiom isn't "if (!set.next())", it's "while (set.next())". It's good to use common idioms, because it makes it easier for other people to understand your code.
But see if you have a repeated login ID.
And step through in a debugger to see what's going on.
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