|
| 1 | +## 支持UDF,UDTF,UDAT: |
| 2 | + |
| 3 | +### UDTF使用案例 |
| 4 | + |
| 5 | +1. cross join:左表的每一行数据都会关联上UDTF 产出的每一行数据,如果UDTF不产出任何数据,那么这1行不会输出。 |
| 6 | +2. left join:左表的每一行数据都会关联上UDTF 产出的每一行数据,如果UDTF不产出任何数据,则这1行的UDTF的字段会用null值填充。 left join UDTF 语句后面必须接 on true参数。 |
| 7 | + |
| 8 | + |
| 9 | +场景:将某个字段拆分为两个字段。 |
| 10 | + |
| 11 | +```$xslt |
| 12 | +
|
| 13 | +create table function UDTFOneColumnToMultiColumn with cn.todd.flink180.udflib.UDTFOneColumnToMultiColumn; |
| 14 | +
|
| 15 | +CREATE TABLE MyTable ( |
| 16 | + userID VARCHAR , |
| 17 | + eventType VARCHAR, |
| 18 | + productID VARCHAR) |
| 19 | +WITH ( |
| 20 | + type = 'kafka11', |
| 21 | + bootstrapServers = '172.16.8.107:9092', |
| 22 | + zookeeperQuorum = '172.16.8.107:2181/kafka', |
| 23 | + offsetReset = 'latest', |
| 24 | + topic ='mqTest03', |
| 25 | + topicIsPattern = 'false' |
| 26 | +); |
| 27 | +
|
| 28 | +CREATE TABLE MyTable1 ( |
| 29 | + channel VARCHAR , |
| 30 | + pv VARCHAR, |
| 31 | + name VARCHAR) |
| 32 | +WITH ( |
| 33 | + type = 'kafka11', |
| 34 | + bootstrapServers = '172.16.8.107:9092', |
| 35 | + zookeeperQuorum = '172.16.8.107:2181/kafka', |
| 36 | + offsetReset = 'latest', |
| 37 | + topic ='mqTest01', |
| 38 | + topicIsPattern = 'false' |
| 39 | +); |
| 40 | +
|
| 41 | +CREATE TABLE MyTable2 ( |
| 42 | + userID VARCHAR, |
| 43 | + eventType VARCHAR, |
| 44 | + productID VARCHAR, |
| 45 | + date1 VARCHAR, |
| 46 | + time1 VARCHAR |
| 47 | +) |
| 48 | +WITH ( |
| 49 | + type = 'console', |
| 50 | + bootstrapServers = '172.16.8.107:9092', |
| 51 | + zookeeperQuorum = '172.16.8.107:2181/kafka', |
| 52 | + offsetReset = 'latest', |
| 53 | + topic ='mqTest02', |
| 54 | + topicIsPattern = 'false' |
| 55 | +); |
| 56 | +
|
| 57 | +## 视图使用UDTF |
| 58 | +--create view udtf_table as |
| 59 | +-- select MyTable.userID,MyTable.eventType,MyTable.productID,date1,time1 |
| 60 | + -- from MyTable LEFT JOIN lateral table(UDTFOneColumnToMultiColumn(productID)) |
| 61 | + -- as T(date1,time1) on true; |
| 62 | + |
| 63 | + |
| 64 | + |
| 65 | + |
| 66 | +insert |
| 67 | + into |
| 68 | + MyTable2 |
| 69 | +select |
| 70 | + userID,eventType,productID,date1,time1 |
| 71 | +from |
| 72 | + ( |
| 73 | + select MyTable.userID,MyTable.eventType,MyTable.productID,date1,time1 |
| 74 | + from MyTable ,lateral table(UDTFOneColumnToMultiColumn(productID)) as T(date1,time1)) as udtf_table; |
| 75 | +
|
| 76 | +``` |
| 77 | +一行转多列UDTFOneColumnToMultiColumn |
| 78 | + |
| 79 | +```$xslt |
| 80 | +public class UDTFOneColumnToMultiColumn extends TableFunction<Row> { |
| 81 | + public void eval(String value) { |
| 82 | + String[] valueSplits = value.split("_"); |
| 83 | +
|
| 84 | + //一行,两列 |
| 85 | + Row row = new Row(2); |
| 86 | + row.setField(0, valueSplits[0]); |
| 87 | + row.setField(1, valueSplits[1]); |
| 88 | + collect(row); |
| 89 | + } |
| 90 | +
|
| 91 | + @Override |
| 92 | + public TypeInformation<Row> getResultType() { |
| 93 | + return new RowTypeInfo(Types.STRING, Types.STRING); |
| 94 | + } |
| 95 | +} |
| 96 | +``` |
| 97 | + |
| 98 | +输入输出: |
| 99 | + |
| 100 | + |
| 101 | +输入: {"userID": "user_5", "eventType": "browse", "productID":"product_5"} |
| 102 | + |
| 103 | +输出: |
| 104 | + |
| 105 | + +--------+-----------+-----------+---------+-------+ |
| 106 | + | userID | eventType | productID | date1 | time1 | |
| 107 | + +--------+-----------+-----------+---------+-------+ |
| 108 | + | user_5 | browse | product_5 | product | 5 | |
| 109 | + +--------+-----------+-----------+---------+-------+ |
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