Java PreparedStatement Arraylist SQL

Question

Unable to insert new values ​​into my DB from ArrayList; I want to add all ArrayList columns to the columns , title, about values ​​from ArrayLists parsgetListId (), getTitleId (), pars.getAboutAr ().

String query = "insert into test (list, title, about)" + "VALUES (?, ?, ?)";

    try {
        pars.htmlParse("hello");
        PreparedStatement preparedStmt = db.getConnection().prepareStatement(query);
        for (int i = 0; i < pars.getListId().size(); i++) {
            preparedStmt.setString(1, pars.getListId().get(i));
            preparedStmt.executeUpdate();
        }
        for (int i = 0; i < pars.getTitleId().size(); i++) {
            preparedStmt.setString(2, pars.getTitleId().get(i));
            preparedStmt.executeUpdate();
        }
        for (int i = 0; i < pars.getAboutAr().size(); i++) {
            preparedStmt.setString(3, pars.getAboutAr().get(i));
            preparedStmt.executeUpdate();
        }
        preparedStmt.execute();


        } catch (IOException e1) {
        e1.printStackTrace();

Answer 1

You must set all three columns before you call executeUpdateeven once.

You doing:

        preparedStmt.setString(1, pars.getListId().get(i));
        preparedStmt.executeUpdate();

So, you only set the first parameter in the prepared statement, and then call executeUpdate. But you need to have all three.

You should have a loop that inserts all three together:

    for (int i = 0; i < pars.getListId().size(); i++) {
        preparedStmt.setString(1, pars.getListId().get(i));
        preparedStmt.setString(2, pars.getTitleId().get(i));
        preparedStmt.setString(3, pars.getAboutAr().get(i));
        preparedStmt.executeUpdate();
    }

. , insert .

, , pars.getListId() 5 , , pars.getTitleId() pars.getAboutAr() 4 . , , i 4, , pars.getTitleId() 4 ( 4 ).

.

• , , .

• . :

  int minSize = Collections.min( Arrays.asList( pars.getListId().size(),
                                                pars.getTitleId().size(),
                                                pars.getAboutAr().size() ) );
  

  for (int i = 0; i < minSize; i++) {
      preparedStmt.setString(1, pars.getListId().get(i));
      preparedStmt.setString(2, pars.getTitleId().get(i));
      preparedStmt.setString(3, pars.getAboutAr().get(i));
      preparedStmt.executeUpdate();
  }
  

  , .

• (do max min ) ( , i) , setNull setString.

• pars , , . , , Par - , id, title about. Par pars . , , .

Answer 2

, 1, 2 3 .Update().

, ( )

    for (int i = 0; i < pars.getListId().size(); i++) {
        preparedStmt.setString(1, pars.getListId().get(i));
        preparedStmt.setString(2, pars.getTitleId().get(i));
        preparedStmt.setString(3, pars.getAboutAr().get(i));
        preparedStmt.executeUpdate();
    }

3 .

Answer 3

Instead of trying to set each parameter and then perform an update that leaves the request in an invalid state (since not all parameters are set), you must set each parameter for each item and then perform the update.

A better solution would be to use a batch update process like

String query = "insert into test (list, title, about)" + "VALUES (?, ?, ?)";
try (PreparedStatement ps = con.prepareStatement(query)) {
    pars.htmlParse("hello");
    for (int index = 0; index < pars.getListId().size(); index++) {
        ps.setString(1, pars.getListId().get(index));
        ps.setString(2, pars.getTitleId().get(index));
        ps.setString(3, pars.getAboutAr().get(index));
        ps.addBatch();
    }
    ps.executeBatch();
} catch (SQLException exp) {
    exp.printStackTrace();
}