1、impala/spark常见的命令汇总
| 常见命令 |
impala |
spark sql |
| create语句 |
CREATE TABLE IF NOT EXISTS my_db.student (name STRING, age INT, contact INT ); |
CREATE TABLE t2_part(user_id BIGINT, firstname STRING, lastname STRING)PARTITIONED BY(ds STRING); |
| insert语句 |
Insert into（overwrite） table_name values (value1, value2, value2); |
Insert into（overwrite） table_name values (value1, value2, value2); |
| select语句 |
SELECT column1, column2, columnN from table_name; |
SELECT column1, column2, columnN from table_name; |
| describe语句 |
Describe table_name; |
Describe table_name; |
| alter语句 |
ALTER TABLE my_db.customers RENAME TO my_db.users; |
ALTER TABLE t1 RENAME TO new_t1; |
| drop语句 |
DROP table database_name.table_name; |
|
| truncate语句 |
truncate table_name; |
|
| show语句 |
show tables; |
SHOW CREATE TABLE new_t1; |
| create view语句 |
Create View IF NOT EXISTS view_name as Select statement |
Create View view_name as Select statement |
| alter view语句 |
ALTER VIEW database_name.view_name为Select语句 |
ALTER VIEW database_name.view_name as |
| drop view语句 |
DROP VIEW database_name.view_name; |
DROP VIEW database_name.view_name; |
| analyze table语句 |
|
ANALYZE TABLE new_t1 COMPUTE STATISTICS FOR COLUMNS; |
上述总结的不全，日常需要持续积累。不过需要关注的是impala和spark sql部分语法差异。
| 函数 |
impala |
spark sql |
presto |
hive |
| CAST ( expression AS data_type ) |
支持 |
- |
|
|
| substring( string, start, length) |
start从1开始 |
start 0、1均可 |
start从1开始 |
start从 0、1均可 |
| substr( string, start, length) |
start从1开始 |
start 0、1均可 |
start从1开始 |
start从 0、1均可 |
https://prestodb.io/docs/current/functions/string.html
2、参考
1、impala 教程
2、sparkSQL语句总结
3、Apache Impala - Interactive SQL
