Limit the Number of Rows Returned from a SQL Query : Query ResultSet « Database « Java Tutorial

1. Java Tutorial
2. Database
3. Query ResultSet

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.SQLWarning;
import java.sql.Statement;

public class Main {
  public static void main(String[] args) throws Exception {

    Connection conn = getConnection();

    conn.setAutoCommit(false);
    Statement st = conn.createStatement();
    
    st.setFetchSize(1);
    
    st.executeUpdate("create table survey (id int,name varchar(30));");
    st.executeUpdate("insert into survey (id,name ) values (1,'nameValue')");
    st.executeUpdate("insert into survey (id,name ) values (2,'nameValue')");
    st = conn.createStatement();
    ResultSet rs = st.executeQuery("SELECT * FROM survey");
    
    rs.setFetchSize(1);
    
    outputResultSet(rs);

    checkForWarning(rs.getWarnings());

    rs.close();
    st.close();
    conn.close();

  }

  static boolean checkForWarning(SQLWarning w) {
    if (w == null) {
      return false;
    }
    do {
      System.err.println("Warning:\nMessage: " + w.getMessage());
      System.err.println("SQL state: " + w.getSQLState());
      System.err.println("Vendor code: " + w.getErrorCode() + "\n----------------");
    } while ((w = w.getNextWarning()) != null);
    return true;
  }

  private static void outputResultSet(ResultSet rs) throws Exception {
    ResultSetMetaData rsMetaData = rs.getMetaData();
    int numberOfColumns = rsMetaData.getColumnCount();
    for (int i = 1; i < numberOfColumns + 1; i++) {
      String columnName = rsMetaData.getColumnName(i);
      System.out.print(columnName + "   ");

    }
    System.out.println();
    System.out.println("----------------------");

    while (rs.next()) {
      for (int i = 1; i < numberOfColumns + 1; i++) {
        System.out.print(rs.getString(i) + "   ");
      }
      System.out.println();
    }

  }

  private static Connection getConnection() throws Exception {
    Class.forName("org.hsqldb.jdbcDriver");
    String url = "jdbc:hsqldb:mem:data/tutorial";

    return DriverManager.getConnection(url, "sa", "");
  }
}