????MaxCompute SQL???????????Update??Delete?????????????????п????????Щ??????????????????????????????MaxCompute SQL??Insert?????Insert Into/Overwrite????????????????????????????????д??????д??????????????д???????????????д??????????????д??????????????????????????????????μ????????????????????????????????????????????д??????????????????μ??????????????????
????Update
???????????????????????Insert Overwrite???????????Update??????????Update?????????Update???????????Update??????????????????????Update?????Select?????????Insert Overwrite????????????Update????????????ü?????????????????·??????
????--?????
+------------+------------+------------+------------+------------+------------+------------+------------+
| empno      | ename      | job        | mgr        | hiredate   | sal        | comm       | deptno     |
+------------+------------+------------+------------+------------+------------+------------+------------+
| 7499       | ALLEN      | SALESMAN   | 7698     | 1981-02-20 00:00:00 | 1600.0     | 300.0      | 30       |
| 7521       | WARD       | SALESMAN   | 7698     | 1981-02-22 00:00:00 | 1250.0     | 500.0      | 30       |
| 7654       | MARTIN     | SALESMAN   | 7698     | 1981-09-28 00:00:00 | 1250.0     | 1400.0     | 30       |
| 7698       | BLAKE      | MANAGER    | 7839     | 1981-05-01 00:00:00 | 2850.0     | NULL       | 30       |
| 7782       | CLARK      | MANAGER    | 7839     | 1981-06-09 00:00:00 | 2450.0     | NULL       | 10       |
| 7844       | TURNER     | SALESMAN   | 7698     | 1981-09-08 00:00:00 | 1500.0     | 0.0        | 30       |
| 7900       | JAMES      | CLERK      | 7698     | 1981-12-03 00:00:00 | 950.0      | NULL       | 30       |
| 7902       | FORD       | ANALYST    | 7566     | 1981-12-03 00:00:00 | 3000.0     | NULL       | 20       |
| 7788       | SCOTT      | ANALYST    | 7566     | 1987-07-13 01:00:00 | 3000.0     | NULL       | 20       |
| 7876       | ADAMS      | CLERK      | 7788     | 1987-07-13 01:00:00 | 1100.0     | NULL       | 20       |
+------------+------------+------------+------------+------------+------------+------------+------------+
????--?SQL
????Update Table emp Set comm  = 0 where comm is null;
????--??SQL
????--????????и????????coalesce?????????????case when??????????
Insert Overwrite table emp Select empno??ename?? job??mgr??hiredate??sal??case when comm is null then 0.0 else comm end as comm??deptno from emp;
+------------+------------+------------+------------+------------+------------+------------+------------+
| empno      | ename      | job        | mgr        | hiredate   | sal        | comm       | deptno     |
+------------+------------+------------+------------+------------+------------+------------+------------+
| 7698       | BLAKE      | MANAGER    | 7839     | 1981-05-01 00:00:00 | 2850.0     | 0.0        | 30       |
| 7788       | SCOTT      | ANALYST    | 7566     | 1987-07-13 01:00:00 | 3000.0     | 0.0        | 20       |
| 7782       | CLARK      | MANAGER    | 7839     | 1981-06-09 00:00:00 | 2450.0     | 0.0        | 10       |
| 7902       | FORD       | ANALYST    | 7566     | 1981-12-03 00:00:00 | 3000.0     | 0.0        | 20       |
| 7876       | ADAMS      | CLERK      | 7788     | 1987-07-13 01:00:00 | 1100.0     | 0.0        | 20       |
| 7900       | JAMES      | CLERK      | 7698     | 1981-12-03 00:00:00 | 950.0      | 0.0        | 30       |
| 7499       | ALLEN      | SALESMAN   | 7698     | 1981-02-20 00:00:00 | 1600.0     | 300.0      | 30       |
| 7654       | MARTIN     | SALESMAN   | 7698     | 1981-09-28 00:00:00 | 1250.0     | 1400.0     | 30       |
| 7844       | TURNER     | SALESMAN   | 7698     | 1981-09-08 00:00:00 | 1500.0     | 0.0        | 30       |
| 7521       | WARD       | SALESMAN   | 7698     | 1981-02-22 00:00:00 | 1250.0     | 500.0      | 30       |
+------------+------------+------------+------------+------------+------------+------------+------------+
????????????????????????????????????÷??????Insert????Select????????????????????????????
????Delete
????Delete????????????????????????????????????????????????????????????
??????????????
??????????????????????????? TRUNCATE TABLE table_name; ??????????????????
????????????????????????????????? ALTER TABLE table_name DROP PARTITION; ???????????????????????????????????????(????????????????????????)??
odps@ aliyun2014>show partitions partition_table;
ds=20160101
ds=20160102
OK
odps@ aliyun2014>alter table partition_table drop if exists partition(ds='20160102');
Confirm to "alter table partition_table drop if exists partition(ds='20160102');" (yes/no)? yes
OK
>show partitions partition_table;
ds=20160101
OK
???????????????
??????????????????????where?????????????????????????Delete?????Insert Overwrite?????????????????????????????????????д????μ??????????????????????????????д??????????????????????????????Update???????????????????????Insert???????????????????????????????????
????--????????????????Update????emp???в???
????--?SQL ???????????job?SALESMAN????
????Delete from emp where comm >500;
????--??SQL???????????????Щ??????????????Union all
????Insert Overwrite Table Emp Select * From Emp Where  comm <=500 or comm is null;
????--?????
+------------+------------+------------+------------+------------+------------+------------+------------+
| empno      | ename      | job        | mgr        | hiredate   | sal        | comm       | deptno     |
+------------+------------+------------+------------+------------+------------+------------+------------+
| 7698       | BLAKE      | MANAGER    | 7839     | 1981-05-01 00:00:00 | 2850.0     | NULL       | 30       |
| 7788       | SCOTT      | ANALYST    | 7566     | 1987-07-13 01:00:00 | 3000.0     | NULL       | 20       |
| 7782       | CLARK      | MANAGER    | 7839     | 1981-06-09 00:00:00 | 2450.0     | NULL       | 10       |
| 7902       | FORD       | ANALYST    | 7566     | 1981-12-03 00:00:00 | 3000.0     | NULL       | 20       |
| 7876       | ADAMS      | CLERK      | 7788     | 1987-07-13 01:00:00 | 1100.0     | NULL       | 20       |
| 7900       | JAMES      | CLERK      | 7698     | 1981-12-03 00:00:00 | 950.0      | NULL       | 30       |
| 7499       | ALLEN      | SALESMAN   | 7698     | 1981-02-20 00:00:00 | 1600.0     | 300.0      | 30       |
| 7844       | TURNER     | SALESMAN   | 7698     | 1981-09-08 00:00:00 | 1500.0     | 0.0        | 30       |
| 7521       | WARD       | SALESMAN   | 7698     | 1981-02-22 00:00:00 | 1250.0     | 500.0      | 30       |
+------------+------------+------------+------------+------------+------------+------------+------------+
??????????????Щ????????????????????????Щ???????С???ɡ??????ЩС????????????????ù???????????Ч???
????????????????????????????????????????????????????????????????????????????????μ?????????????????д???μ???д??????????????????????????????????????????????