public class CategoryDAO {
public int getTotal() {
int total = 0;
try (Connection c = DBUtil.getConnection(); Statement s = c.createStatement()) {
String sql = "select count(*) from Category";
ResultSet rs = s.executeQuery(sql);
while (rs.next()) {
total = rs.getInt(1);
}
} catch (SQLException e) {
e.printStackTrace();
}
return total;
}
public void add(Category bean) {
String sql = "insert into category values(null,?)";
try (Connection c = DBUtil.getConnection(); PreparedStatement ps = c.prepareStatement(sql)) {
ps.setString(1, bean.getName());
ps.execute();
ResultSet rs = ps.getGeneratedKeys();
if (rs.next()) {
int id = rs.getInt(1);
bean.setId(id);
}
} catch (SQLException e) {
e.printStackTrace();
}
}
public void update(Category bean) {
String sql = "update category set name= ? where id = ?";
try (Connection c = DBUtil.getConnection(); PreparedStatement ps = c.prepareStatement(sql)) {
ps.setString(1, bean.getName());
ps.setInt(2, bean.getId());
ps.execute();
} catch (SQLException e) {
e.printStackTrace();
}
}
public void delete(int id) {
try (Connection c = DBUtil.getConnection(); Statement s = c.createStatement()) {
String sql = "delete from Category where id = " + id;
s.execute(sql);
} catch (SQLException e) {
e.printStackTrace();
}
}
public Category get(int id) {
Category bean = null;
try (Connection c = DBUtil.getConnection(); Statement s = c.createStatement()) {
String sql = "select * from Category where id = " + id;
ResultSet rs = s.executeQuery(sql);
if (rs.next()) {
bean = new Category();
String name = rs.getString(2);
bean.setName(name);
bean.setId(id);
}
} catch (SQLException e) {
e.printStackTrace();
}
return bean;
}
public List<Category> list() {
return list(0, Short.MAX_VALUE);
}
public List<Category> list(int start, int count) {
List<Category> beans = new ArrayList<Category>();
String sql = "select * from Category order by id desc limit ?,? ";
try (Connection c = DBUtil.getConnection(); PreparedStatement ps = c.prepareStatement(sql)) {
ps.setInt(1, start);
ps.setInt(2, count);
ResultSet rs = ps.executeQuery();
while (rs.next()) {
Category bean = new Category();
int id = rs.getInt(1);
String name = rs.getString(2);
bean.setId(id);
bean.setName(name);
beans.add(bean);
}
} catch (SQLException e) {
e.printStackTrace();
}
return beans;
}
}