java - 带变量的结果集

Question

好的，基本上我有这段代码:

resultSet = statement.executeQuery("select * from FEEDBACK.COMMENTS");
writeResultSet(resultSet);

private void writeResultSet(ResultSet resultSet) throws SQLException {
    System.out.println("jestem w writeresultset");
    // resultSet is initialised before the first data set
    while (resultSet.next()) {
        // it is possible to get the columns via name
        // also possible to get the columns via the column number
        // which starts at 1
        // e.g., resultSet.getSTring(2);
        String id = resultSet.getString("id");
        String user = resultSet.getString("IMIE");
        String website = resultSet.getString("NAZWISKO");
        String summary = resultSet.getString("ADRES");
        String date = resultSet.getString("EMAIL");
        String comment = resultSet.getString("TELEFON");
        String opisso = resultSet.getString("OPIS");

        JTextField myOutput = new JTextField(1600);
        myOutput.setText("id w bazie danych to " + id + " imie to " + user 
            + " nazwisko to " + website + " adres to " + summary + " email to " 
            + date + " teelefon to " + comment + " opis to " + opisso);

        add(myOutput);     
    }
}    

我想实现的是:

resultSet = statement.executeQuery("select * from FEEDBACK.COMMENTS 
    where NAZWISKO LIKE " variable );
writeResultSet(resultSet);

我想按已定义的变量进行搜索，但是我卡住了，不知道该怎么做。

Answer 1

使用PreparedStatement:

String nazwisko = ...
String query = "select * from FEEDBACK.COMMENTS where NAZWISKO LIKE ?";
PreparedStatement pstmt = con.prepareStatement(query);
pstmt.setString(1, nazwisko);
ResultSet rs = pstmt.execute();
while (resultSet.next()) {
    //...
}

如果您需要为您的LIKE 使用通配符，请选择以下之一:

nazwisko = nazwisko + "%";
nazwisko = "%" + nazwisko;
nazwisko = "%" + nazwisko + "%";