# 写入时复制（CoW）创建表示例
<a name="querying-hudi-copy-on-write-create-table-examples"></a>

如果您有已在 Amazon Glue 中创建的 Hudi 表，您可以直接在 Athena 中查询它们。当您在 Athena 中创建分区 Hudi 表时，您必须运行 `ALTER TABLE ADD PARTITION` 以加载 Hudi 数据，然后再查询这些数据。

## 未分区 CoW 表
<a name="querying-hudi-nonpartitioned-cow-table"></a>

以下示例在 Athena 中创建了一个未分区的 CoW 表。

```
CREATE EXTERNAL TABLE `non_partition_cow`(
  `_hoodie_commit_time` string,
  `_hoodie_commit_seqno` string,
  `_hoodie_record_key` string,
  `_hoodie_partition_path` string,
  `_hoodie_file_name` string,
  `event_id` string,
  `event_time` string,
  `event_name` string,
  `event_guests` int,
  `event_type` string)
ROW FORMAT SERDE
  'org.apache.hadoop.hive.ql.io.parquet.serde.ParquetHiveSerDe'
STORED AS INPUTFORMAT
  'org.apache.hudi.hadoop.HoodieParquetInputFormat'
OUTPUTFORMAT
  'org.apache.hadoop.hive.ql.io.parquet.MapredParquetOutputFormat'
LOCATION
  's3://amzn-s3-demo-bucket/folder/non_partition_cow/'
```

## 分区 CoW 表
<a name="querying-hudi-partitioned-cow-table"></a>

以下示例在 Athena 中创建了一个已分区的 CoW 表。

```
CREATE EXTERNAL TABLE `partition_cow`(
  `_hoodie_commit_time` string, 
  `_hoodie_commit_seqno` string, 
  `_hoodie_record_key` string, 
  `_hoodie_partition_path` string, 
  `_hoodie_file_name` string, 
  `event_id` string, 
  `event_time` string, 
  `event_name` string, 
  `event_guests` int)
PARTITIONED BY ( 
  `event_type` string)
ROW FORMAT SERDE 
  'org.apache.hadoop.hive.ql.io.parquet.serde.ParquetHiveSerDe' 
STORED AS INPUTFORMAT 
  'org.apache.hudi.hadoop.HoodieParquetInputFormat' 
OUTPUTFORMAT 
  'org.apache.hadoop.hive.ql.io.parquet.MapredParquetOutputFormat' 
LOCATION
  's3://amzn-s3-demo-bucket/folder/partition_cow/'
```

以下 `ALTER TABLE ADD PARTITION` 示例将两个分区添加到了示例 `partition_cow` 表。

```
ALTER TABLE partition_cow ADD
  PARTITION (event_type = 'one') LOCATION 's3://amzn-s3-demo-bucket/folder/partition_cow/one/' 
  PARTITION (event_type = 'two') LOCATION 's3://amzn-s3-demo-bucket/folder/partition_cow/two/'
```