如何使用spring JDBC Template批处理在数据库中进行多次插入？

Question

我需要一次性在数据库中插入数千条记录.我在我的应用程序中使用spring JDBC模板.

下面是我到目前为止编写的代码,它一次执行所有插入.所以,如果我有10,000个用户,他们一次插入.但我想要的是批量执行它们,例如一批500条记录,等等.

@Override
public void saveBatch(final List<Employee> employeeList) {
    final int batchSize = 500;

    getJdbcTemplate().batchUpdate(QUERY_SAVE,
            new BatchPreparedStatementSetter() {
                @Override
                public void setValues(PreparedStatement ps, int i)
                        throws SQLException {
                    Employee employee = employeeList.get(i);
                    ps.setString(1, employee.getFirstname());
                    ps.setString(2, employee.getLastname());
                    ps.setString(3, employee.getEmployeeIdOnSourceSystem());
                }

                @Override
                public int getBatchSize() {
                    return employeeList.size();
                }
            });

}

如何更改上面的代码,以便代替employeeList.size()作为批量大小,我们可以将批量大小称为500,执行它们然后下一个500,依此类推？

请帮忙.

Answer 1

我不确定你是否可以单独使用JDBC模板.也许您可以batchUpdate通过将大列表切成批量大小的块来逐步调用该方法.

看看这里:

@Override
public void saveBatch(final List<Employee> employeeList) {
    final int batchSize = 500;

    for (int j = 0; j < employeeList.size(); j += batchSize) {

        final List<Employee> batchList = employeeList.subList(j, j + batchSize > employeeList.size() ? employeeList.size() : j + batchSize);

        getJdbcTemplate().batchUpdate(QUERY_SAVE,
            new BatchPreparedStatementSetter() {
                @Override
                public void setValues(PreparedStatement ps, int i)
                        throws SQLException {
                    Employee employee = batchList.get(i);
                    ps.setString(1, employee.getFirstname());
                    ps.setString(2, employee.getLastname());
                    ps.setString(3, employee.getEmployeeIdOnSourceSystem());
                }

                @Override
                public int getBatchSize() {
                    return batchList.size();
                }
            });

    }
}

Answer 2

我知道这有点晚了但你可以做类似于@adarshr正在做的事情,除了使用Google GuavaLists.partition获取子列表.

public void saveBatch(final List<Employee> employeeList) {
    final int batchSize = 500;
    List<List<Employee>> batchLists = Lists.partition(employeeList, batchSize);

    for(List<Employee> batch : batchLists) {  
        getJdbcTemplate().batchUpdate(QUERY_SAVE, new BatchPreparedStatementSetter() {
            @Override
            public void setValues(PreparedStatement ps, int i)
                    throws SQLException {
                Employee employee = batch.get(i);
                ps.setString(1, employee.getFirstname());
                ps.setString(2, employee.getLastname());
                ps.setString(3, employee.getEmployeeIdOnSourceSystem());
            }

            @Override
            public int getBatchSize() {
                return batch.size();
            }
        });
    }
}

Answer 3

Spring 提供了多批次的 Batch 操作。在下面的示例中，批量大小为 100。

 public class JdbcActorDao implements ActorDao {

    private JdbcTemplate jdbcTemplate;

    public void setDataSource(DataSource dataSource) {
        this.jdbcTemplate = new JdbcTemplate(dataSource);
    }

    public int[][] batchUpdate(final Collection<Actor> actors) {
        int[][] updateCounts = jdbcTemplate.batchUpdate(
                "update t_actor set first_name = ?, last_name = ? where id = ?",
                actors,
                100,
                new ParameterizedPreparedStatementSetter<Actor>() {
                    public void setValues(PreparedStatement ps, Actor argument) throws SQLException {
                        ps.setString(1, argument.getFirstName());
                        ps.setString(2, argument.getLastName());
                        ps.setLong(3, argument.getId().longValue());
                    }
                });
        return updateCounts;
    }

    // ... additional methods

 }