Regular columns - ApsaraDB for OceanBase - Alibaba Cloud Documentation Center

This topic describes the conversion scope of CREATE TABLE DDL operations for defining regular columns during data migration from an Oracle database to an Oracle tenant of OceanBase Database.

Syntax

column_definition:
column [ datatype [ COLLATE column_collation_name ] ]
  [ SORT ] [ VISIBLE | INVISIBLE ]
  [ DEFAULT [ ON NULL ] expr | identity_clause ]
  [ ENCRYPT encryption_spec ]
  [ { inline_constraint }...
  | inline_ref_constraint
  ]
  
identity_clause:
GENERATED [ ALWAYS | BY DEFAULT [ ON NULL ] ] AS IDENTITY [ ( identity_options ) ]

encryption_spec:
[ USING 'encrypt_algorithm' ][ IDENTIFIED BY password ][ 'integrity_algorithm' ][ [ NO ] SALT ]

Supported operations

Defining column types by using the column_name datatype clause is supported. For more information about type conversion, see Data type conversion.
Specifying the column visibility attribute by using the VISIBLE | INVISIBLE option is supported. The default value is VISIBLE, which is not declared.
Specifying the default value by using the DEFAULT expr option is supported.
Defining inline constraints by using the inline_constraint | inline_ref_constraint option is supported. For more information, see Constraints.

Ignored clauses and options

Note

The following clauses and options will be ignored and will not be resolved or converted when they are specified in the synchronized DDL statements.

The COLLATE column_collation_name option for defining the column collation.
The SORT option.
The DEFAULT ON NULL expr option for specifying the default value. Sample code:
```
CREATE TABLE T (C NUMBER DEFAULT ON NULL 1);
```

The identity_claim option for defining auto-increment columns. Sample code:

CREATE TABLE t (id NUMBER GENERATED BY DEFAULT AS IDENTITY (start with 100 increment by 10));

The ENCRYPT encryption_spec option for specifying the column encryption attribute.