hive复合类型构建操作,hive复合构建
hive复合类型构建操作,hive复合构建
1. Map类型构建:
map
语法: map (key1, value1, key2, value2, …)
说明:根据输入的key和value对构建map类型
举例:
hive> Create table lxw_test as select map('100','tom','200','mary')as t from lxw_dual;
hive> describe lxw_test;
t map<string,string>
hive> select t from lxw_test;
{"100":"tom","200":"mary"}
2. Struct类型构建: struct
语法: struct(val1, val2, val3, …)
说明:根据输入的参数构建结构体struct类型
举例:
hive> create table lxw_test as select struct('tom','mary','tim')as t from lxw_dual;
hive> describe lxw_test;
t struct<col1:string,col2:string,col3:string>
hive> select t from lxw_test;
{"col1":"tom","col2":"mary","col3":"tim"}
3. array类型构建: array
语法: array(val1, val2, …)
说明:根据输入的参数构建数组array类型
举例:
hive> create table lxw_test as selectarray("tom","mary","tim") as t from lxw_dual;
hive> describe lxw_test;
t array<string>
hive> select t from lxw_test;
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