CREATE TABLE AS

语法

CREATE [EXTERNAL]^① TABLE [IF NOT EXISTS] [catalog_name.][db_name.]table_name [ ( column_alias, ... ) ]

[[PARTITIONED BY ^①(col_name, ....)] [SORT BY^① ([column [, column ...]])] ]^①

[COMMENT 'table_comment']

[ WITH ( property_name = expression [, ...] ) ]^②

[[STORED AS file_format]^①

[LOCATION 'hdfs_path']^①

[TBLPROPERTIES (orc_table_property = value [, ...] ) ] ]^①

AS query

[ WITH [ NO ] DATA ]^②

限制

① 和 ②的语法不能组合使用。

当使用了avro_schema_url属性时，以下操作是不支持的：

• 不支持CREATE TABLE AS操作
• 使用CREATE TABLE时不支持partitioned_by 和 bucketed_by
• 不支持使用alter table修改column

描述

创建包含SELECT查询结果的新表。

使用CREATE TABLE创建空表。

使用IF NOT EXISTS子句时，如果表已经存在则不会报错。

可选WITH子句可用于设置新创建的表的属性，如表的存储位置（location）、是不是外表（external）等。

示例

• 用指定列的查询结果创建新表orders_column_aliased：

  CREATE TABLE orders_column_aliased (order_date, total_price) 
  AS
  SELECT orderdate, totalprice FROM orders;

• 用表orders的汇总结果新建一个表orders_by_data：

  CREATE TABLE orders_by_date
  COMMENT 'Summary of orders by date'
  WITH (format = 'ORC')
  AS
  SELECT orderdate, sum(totalprice) AS price
  FROM orders
  GROUP BY orderdate;

• 如果表orders_by_date不存在，则创建表orders_by_date：

  CREATE TABLE IF NOT EXISTS orders_by_date AS
  SELECT orderdate, sum(totalprice) AS price
  FROM orders
  GROUP BY orderdate;

• 用和表orders具有相同schema创建新表empty_orders table，但是没数据：

  CREATE TABLE empty_orders AS
  SELECT *
  FROM orders
  WITH NO DATA;

• 使用VALUES 创建表，参考 VALUES。
• 分区表示例:

  CREATE EXTERNAL TABLE hetu_copy(corderkey, corderstatus, ctotalprice, corderdate, cds) 
   PARTITIONED BY(cds)  
   SORT BY (corderkey, corderstatus) 
   COMMENT 'test'  
   STORED AS orc  
   LOCATION '/user/hetuserver/tmp'  
   TBLPROPERTIES (orc_bloom_filter_fpp = 0.3, orc_compress = 'SNAPPY', orc_compress_size = 6710422, orc_bloom_filter_columns = 'corderstatus,ctotalprice')  
   as select * from hetu_test; 
    
   CREATE TABLE hetu_copy1(corderkey, corderstatus, ctotalprice, corderdate, cds)  
   WITH (partitioned_by = ARRAY['cds'], bucketed_by = ARRAY['corderkey', 'corderstatus'],  
   sorted_by = ARRAY['corderkey', 'corderstatus'],  
   bucket_count = 16,  
   orc_compress = 'SNAPPY',  
   orc_compress_size = 6710422,  
   orc_bloom_filter_columns = ARRAY['corderstatus', 'ctotalprice'],  
   external = true,  
   format = 'orc',  
   location = '/user/hetuserver/tmp ') 
    as select * from hetu_test;