Java 类名:com.alibaba.alink.operator.batch.sql.OrderByBatchOp
Python 类名:OrderByBatchOp
功能介绍
对批式数据进行sql的ORDER BY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 | ✓ | | |
| fetch | fetch的record数目 | fetch的record数目 | Integer | | | |
| limit | record的limit数 | record的limit数 | Integer | | | |
| offset | fetch的偏移值 | fetch的偏移值 | Integer | | | |
| order | 排序方法 | 排序方法 | String | | | “asc” |
代码示例
Python 代码
from pyalink.alink import *
import pandas as pd
useLocalEnv(1)
df = pd.DataFrame([
['Ohio', 2000, 1.5],
['Ohio', 2000, 1.5],
['Ohio', 2002, 3.6],
['Nevada', 2001, 2.4],
['Nevada', 2002, 2.9],
['Nevada', 2003, 3.2]
])
batch_data = BatchOperator.fromDataframe(df, schemaStr='f1 string, f2 bigint, f3 double')
batch_data.link(OrderByBatchOp().setClause("f2")).print()
Java 代码
import com.alibaba.alink.operator.batch.BatchOperator;
import com.alibaba.alink.operator.batch.source.MemSourceBatchOp;
import com.alibaba.alink.operator.batch.sql.OrderByBatchOp;
import org.junit.Test;
public class OrderByBatchOpTest {
@Test
public void testOrderByBatchOp() throws Exception {
List <Row> df = Arrays.asList(
Row.of("Ohio", 2000, 1.5),
Row.of("Ohio", 2000, 1.5),
Row.of("Ohio", 2002, 3.6),
Row.of("Nevada", 2001, 2.4),
Row.of("Nevada", 2002, 2.9),
Row.of("Nevada", 2003, 3.2)
);
BatchOperator <?> data = new MemSourceBatchOp(df, "f1 string, f2 int, f3 double");
data.link(new OrderByBatchOp().setClause("f2")).print();
}
}
运行结果
| f1 | f2 | f3 | | —- | —- | —- |
| Ohio | 2000 | 1.5000 |
| Ohio | 2000 | 1.5000 |
| Nevada | 2001 | 2.4000 |
| Ohio | 2002 | 3.6000 |
| Nevada | 2002 | 2.9000 |
| Nevada | 2003 | 3.2000 |