插入行并获取生成的ID

Question

我正在尝试使用Spring的JdbcTemplate类在名为MySQL的表中插入一行transaction并获取生成的ID.相关代码是:

public Transaction insertTransaction(final Transaction tran) {

    // Will hold the ID of the row created by the insert
    KeyHolder keyHolder = new GeneratedKeyHolder();

    getJdbcTemplate().update(new PreparedStatementCreator() {
        public PreparedStatement createPreparedStatement(Connection connection) throws SQLException {

            PreparedStatement ps = connection.prepareStatement(INSERT_TRAN_SQL);
            ps.setString(1, tran.getTransactionType().toString());

            Date sqlDate = new Date(tran.getDate().getTime());
            ps.setDate(2, sqlDate);
            ps.setString(3, tran.getDescription());

            return ps;
        }
    }, keyHolder);

    tran.setId(keyHolder.getKey().longValue());
    return tran;
}

但是调用引发了以下异常 getJdbcTemplate().update

java.sql.SQLException:未请求生成的密钥.您需要将Statement.RETURN_GENERATED_KEYS指定为Statement.executeUpdate()或Connection.prepareStatement().

我可以插入行并获取生成的ID,而不会放弃JdbcTemplate吗？我使用的是Spring 2.5,MySQL 5.5.27和MySQL Connector 5.1.26.

Answer 1

有一种更简单的方法来获得这种行为:

protected JdbcTemplate            jdbcTemplate;
private SimpleJdbcInsert          insert;

    this.jdbcTemplate = new JdbcTemplate(this.databaseSetup.getDataSource());
    this.insert = new SimpleJdbcInsert(this.jdbcTemplate).withTableName(this.tableName).usingGeneratedKeyColumns(this.pkColumn);

然后创建一个名为parameters的Map,它包含表中每个列名的值,并插入如下记录:

    final Map<String, Object> parameters = new HashMap<>();
    parameters.put("empName", employee.getName()); // store the String name of employee in the column empName
    parameters.put("dept", employee.getDepartment()); // store the int (as Integer) of the employee in the column dept
    final Number key = this.insert.executeAndReturnKey(parameters);
    final long pk = key.longValue();

Answer 2

请准备好Statement以下内容

PreparedStatement ps = connection.prepareStatement(
                           INSERT_TRAN_SQL, Statement.RETURN_GENERATED_KEYS);

底层JDBC驱动程序(JdbcTemplate在这里通过Spring间接使用)需要提示您要检索生成的密钥.这可以在准备PreparedStatementas时完成

connection.prepareStatement(strSQL, Statement.RETURN_GENERATED_KEYS);

或者,在执行Statementas时

statement.executeUpdate(strSQL, Statement.RETURN_GENERATED_KEYS);

这也是你java.sql.SQLException所指的.