CREATE-TABLE-AS-SELECT

Name

CREATE TABLE AS SELECT

Description

This statement creates the table structure by returning the results from the Select statement and imports the data at the same time

grammar：

CREATE TABLE table_name [( column_name_list )]
    opt_engine:engineName
    opt_keys:keys
    opt_comment:tableComment
    opt_partition:partition
    opt_distribution:distribution
    opt_rollup:index
    opt_properties:tblProperties
    opt_ext_properties:extProperties
    KW_AS query_stmt:query_def

illustrate:

• The user needs to haveSELECTpermission for the source table andCREATEpermission for the target database

• After a table is created, data is imported. If the import fails, the table is deleted

• You can specify the key type. The default key type is Duplicate Key

• All columns of type string (varchar/var/string) are created as type "string".

• If the created source is an external table and the first column is of type String, the first column is automatically set to VARCHAR(65533). Because of Doris internal table, String column is not allowed as first column.

Example

1. Using the field names in the SELECT statement

   create table `test`.`select_varchar` 
   PROPERTIES("replication_num" = "1") 
   as select * from `test`.`varchar_table`

2. Custom field names (need to match the number of fields returned)

   create table `test`.`select_name`(user, testname, userstatus) 
   PROPERTIES("replication_num" = "1") 
   as select vt.userId, vt.username, jt.status 
   from `test`.`varchar_table` vt join 
   `test`.`join_table` jt on vt.userId=jt.userId

3. Specify table model, partitions, and buckets

   CREATE TABLE t_user(dt, id, name)
   ENGINE=OLAP
   UNIQUE KEY(dt, id)
   COMMENT "OLAP"
   PARTITION BY RANGE(dt)
   (
      FROM ("2020-01-01") TO ("2021-12-31") INTERVAL 1 YEAR
   )
   DISTRIBUTED BY HASH(id) BUCKETS 1
   PROPERTIES("replication_num"="1")
   AS SELECT cast('2020-05-20' as date) as dt, 1 as id, 'Tom' as name;

Keywords

CREATE, TABLE, AS, SELECT

Best Practice