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public class JdbcPreparedStatementCrudPart {
@Test public void testInsert() throws Exception{
Class.forName("com.mysql.cj.jdbc.Driver");
Connection connection = DriverManager.getConnection("jdbc:mysql:///atguigu", "root", "root");
String sql = "insert into t_user(account,password,nickname) values (?,?,?);"; PreparedStatement preparedStatement = connection.prepareStatement(sql);
preparedStatement.setString(1, "test"); preparedStatement.setString(2, "test"); preparedStatement.setString(3, "测试");
int rows = preparedStatement.executeUpdate();
System.out.println(rows);
preparedStatement.close(); connection.close(); }
@Test public void testUpdate() throws Exception{
Class.forName("com.mysql.cj.jdbc.Driver");
Connection connection = DriverManager.getConnection("jdbc:mysql:///atguigu", "root", "root");
String sql = "update t_user set nickname = ? where account = ? ;"; PreparedStatement preparedStatement = connection.prepareStatement(sql);
preparedStatement.setString(1, "tomcat"); preparedStatement.setString(2, "test");
int rows = preparedStatement.executeUpdate();
System.out.println(rows);
preparedStatement.close(); connection.close(); }
@Test public void testDelete() throws Exception{
Class.forName("com.mysql.cj.jdbc.Driver");
Connection connection = DriverManager.getConnection("jdbc:mysql:///atguigu", "root", "root");
String sql = "delete from t_user where account = ? ;"; PreparedStatement preparedStatement = connection.prepareStatement(sql);
preparedStatement.setString(1, "test");
int rows = preparedStatement.executeUpdate();
System.out.println(rows);
preparedStatement.close(); connection.close(); }
@Test public void testQueryMap() throws Exception{
Class.forName("com.mysql.cj.jdbc.Driver");
Connection connection = DriverManager.getConnection("jdbc:mysql:///atguigu", "root", "root");
String sql = "select id,account,password,nickname from t_user ;"; PreparedStatement preparedStatement = connection.prepareStatement(sql);
ResultSet resultSet = preparedStatement.executeQuery();
List<Map> mapList = new ArrayList<>();
ResultSetMetaData metaData = resultSet.getMetaData(); int columnCount = metaData.getColumnCount(); while (resultSet.next()) { Map map = new HashMap(); for (int i = 1; i <= columnCount; i++) { map.put(metaData.getColumnLabel(i), resultSet.getObject(i)); } mapList.add(map); }
System.out.println(mapList);
preparedStatement.close(); connection.close(); resultSet.close(); } }
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