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ScalarFunction：标量函数是实现将0，1，或者多个标量值转化为一个新值TableFunction：一个输入多个行或者多个列AggregateFunction：多个输入一个输出package org.fuwushe.sql;import com.alibaba.fastjson.JSONObject;
import org.apache.flink.api.common.functions.MapFunction;
import org.apache.flink.api.java.DataSet;
import org.apache.flink.api.java.ExecutionEnvironment;
import org.apache.flink.table.api.Table;
import org.apache.flink.table.api.java.BatchTableEnvironment;
import org.apache.flink.table.functions.AggregateFunction;
import org.fuwushe.sql.udf.FromUnixTimeUDF;
import org.fuwushe.sql.udf.Split;import java.util.Iterator;public class SqlUdfTest {public static void main(String []args) throws Exception {ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();BatchTableEnvironment tableEnv = BatchTableEnvironment.create(env);tableEnv.registerFunction("split", new Split("#"));tableEnv.registerFunction("from_unixtime", new FromUnixTimeUDF());tableEnv.registerFunction("wAvg", new WeightedAvg());DataSet<String> input = env.readTextFile("/load/data/udf.txt");DataSet<UdfData> topInput = input.map(new MapFunction<String,UdfData>() {@Overridepublic UdfData map(String s) throws Exception {return JSONObject.parseObject(s,UdfData.class);}});Table udfTable = tableEnv.fromDataSet(topInput);tableEnv.registerTable("udf_table", udfTable);//ScalarFunctionTable udfResult = tableEnv.sqlQuery(" select from_unixtime(`time`) as creatTime,itemId FROM udf_table order by creatTime desc ");tableEnv.toDataSet(udfResult, UdfResult.class).print();//TableFunctionTable udtfResult1 = tableEnv.sqlQuery("SELECT action, word, length FROM udf_table, LATERAL TABLE(split(action)) as T(word, length)");Table udtfResult2 = tableEnv.sqlQuery("SELECT action, word, length FROM udf_table LEFT JOIN LATERAL TABLE(split(action)) as T(word, length) ON TRUE");tableEnv.toDataSet(udtfResult1, UdtfResult.class).print();tableEnv.toDataSet(udtfResult2, UdtfResult.class).print();//AggregateFunction 6 1Table udafResult = tableEnv.sqlQuery("SELECT itemId, wAvg(price,wegiht) AS avgPoints FROM udf_table GROUP BY itemId");tableEnv.toDataSet(udafResult, UdafResult.class).print();}/*** Accumulator for WeightedAvg.*/public static class WeightedAvgAccum {public long sum = 0;public int count = 0;}/*** Weighted Average user-defined aggregate function.*/public static class WeightedAvg extends AggregateFunction<Long, WeightedAvgAccum> {@Overridepublic WeightedAvgAccum createAccumulator() {return new WeightedAvgAccum();}@Overridepublic Long getValue(WeightedAvgAccum acc) {if (acc.count == 0) {return null;} else {return acc.sum / acc.count;}}public void accumulate(WeightedAvgAccum acc, long iValue, int iWeight) {acc.sum += iValue * iWeight;acc.count += iWeight;}public void retract(WeightedAvgAccum acc, long iValue, int iWeight) {acc.sum -= iValue * iWeight;acc.count -= iWeight;}public void merge(WeightedAvgAccum acc, Iterable<WeightedAvgAccum> it) {Iterator<WeightedAvgAccum> iter = it.iterator();while (iter.hasNext()) {WeightedAvgAccum a = iter.next();acc.count += a.count;acc.sum += a.sum;}}public void resetAccumulator(WeightedAvgAccum acc) {acc.count = 0;acc.sum = 0L;}}public static class UdafResult {public UdafResult() {super();}public String itemId;public long avgPoints;public UdafResult(String itemId, long avgPoints) {this.itemId = itemId;this.avgPoints = avgPoints;}@Overridepublic String toString() {return "UdafResult{" + "itemId='" + itemId + '\'' + ", avgPoints=" + avgPoints + '}';}}public static class UdtfResult {public UdtfResult() {super();}public String action;public String word;public int length;public UdtfResult(String action, String word, int length) {this.action = action;this.word = word;this.length = length;}@Overridepublic String toString() {return "UdtfResult{" + "action='" + action + '\'' + ", word='" + word + '\'' + ", length=" + length + '}';}}public static class UdfResult {public UdfResult() {super();}public String itemId;public String creatTime;public UdfResult(String itemId, String creatTime) {this.itemId = itemId;this.creatTime = creatTime;}@Overridepublic String toString() {return "Result{" + "itemId='" + itemId + '\'' + ", creatTime='" + creatTime + '\'' + '}';}}public static class UdfData {public UdfData(String action, String itemId, String time, String unionId, Integer rankIndex, Integer wegiht,long price) {this.action = action;this.itemId = itemId;this.time = time;this.unionId = unionId;this.rankIndex = rankIndex;this.wegiht = wegiht;this.price = price;}public String action;public String itemId;public String time;public String unionId;public Integer rankIndex;public Integer wegiht;public long price;public UdfData() {super();}}
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