Java 类名：com.alibaba.alink.operator.batch.sql.GroupByBatchOp
Python 类名：GroupByBatchOp

功能介绍

对批式数据进行sql的GROUPBY操作。

参数说明

| 名称 | 中文名称 | 描述 | 类型 | 是否必须？ | 取值范围 | 默认值 | | —- | —- | —- | —- | —- | —- | —- |

| groupByPredicate | groupby语句 | groupby语句 | String | ✓ | | |

| selectClause | select语句 | select语句 | String | ✓ | | |

代码示例

Python 代码

  1. from pyalink.alink import *
  3. import pandas as pd
  5. useLocalEnv(1)
  7. df = pd.DataFrame([
  8.     ['Ohio', 2000, 1.5],
  9.     ['Ohio', 2001, 1.7],
  10.     ['Ohio', 2002, 3.6],
  11.     ['Nevada', 2001, 2.4],
  12.     ['Nevada', 2002, 2.9],
  13.     ['Nevada', 2003, 3.2]
  14. ])
  16. batch_data = BatchOperator.fromDataframe(df, schemaStr='f1 string, f2 bigint, f3 double')
  18. op = GroupByBatchOp().setGroupByPredicate("f1").setSelectClause("f1,avg(f2) as f2")
  19. batch_data = batch_data.link(op)
  21. batch_data.print()

Java 代码

  1. import org.apache.flink.types.Row;
  3. import com.alibaba.alink.operator.batch.BatchOperator;
  4. import com.alibaba.alink.operator.batch.source.MemSourceBatchOp;
  5. import com.alibaba.alink.operator.batch.sql.GroupByBatchOp;
  6. import org.junit.Test;
  8. import java.util.Arrays;
  9. import java.util.List;
  11. public class GroupByBatchOpTest {
  12.     @Test
  13.     public void testGroupByBatchOp() throws Exception {
  14.         List <Row> df = Arrays.asList(
  15.             Row.of("Ohio", 2000, 1.5),
  16.             Row.of("Ohio", 2001, 1.7),
  17.             Row.of("Ohio", 2002, 3.6),
  18.             Row.of("Nevada", 2001, 2.4),
  19.             Row.of("Nevada", 2002, 2.9),
  20.             Row.of("Nevada", 2003, 3.2)
  21.         );
  22.         BatchOperator <?> batch_data = new MemSourceBatchOp(df, "f1 string, f2 int, f3 double");
  23.         BatchOperator <?> op = new GroupByBatchOp().setGroupByPredicate("f1").setSelectClause("f1,avg(f2) as f2");
  24.         batch_data = batch_data.link(op);
  25.         batch_data.print();
  26.     }
  27. }

运行结果

| f1 | f2 | | —- | —- |

| Nevada | 2002 |

| Ohio | 2001 |