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

功能介绍

对批式数据进行sql的WHERE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 | | —- | —- | —- | —- | —- | —- | —- |

| clause | 运算语句 | 运算语句 | 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. ])
  15. batch_data = BatchOperator.fromDataframe(df, schemaStr='f1 string, f2 bigint, f3 double')
  16. batch_data.link(WhereBatchOp().setClause("f1='Ohio'"))

Java 代码

  1. import com.alibaba.alink.operator.batch.BatchOperator;
  2. import com.alibaba.alink.operator.batch.source.MemSourceBatchOp;
  3. import com.alibaba.alink.operator.batch.sql.WhereBatchOp;
  4. import org.junit.Test;
  6. public class WhereBatchOpTest {
  7.     @Test
  8.     public void testWhereBatchOp() throws Exception {
  9.         List <Row> df = Arrays.asList(
  10.             Row.of("Ohio", 2000, 1.5),
  11.             Row.of("Ohio", 2001, 1.7),
  12.             Row.of("Ohio", 2002, 3.6),
  13.             Row.of("Nevada", 2001, 2.4),
  14.             Row.of("Nevada", 2002, 2.9),
  15.             Row.of("Nevada", 2003, 3.2)
  16.         );
  17.         BatchOperator <?> data = new MemSourceBatchOp(df, "f1 string, f2 int, f3 double");
  18.         data.link(new WhereBatchOp().setClause("f1='Ohio'")).print();
  19.     }
  20. }

运行结果

| f1 | f2 | f3 | | —- | —- | —- |

| Ohio | 2000 | 1.5000 |

| Ohio | 2001 | 1.7000 |

| Ohio | 2002 | 3.6000 |