SQL操作：OrderBy (OrderByBatchOp)

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