Column Definition
Use the column definition segment of the CREATE EXTERNAL TABLE statement to declare the name and data type of a single column of the new external table.
Column Definition |--+-SAMEAS--template----------------------------------+--------| | .-,---------------------------------------------. | | V | | '---column--data_type--| Other Optional Clauses |-+-' Other Optional Clauses |--+---------------------------------------------------------+--| '-EXTERNAL--CHAR--(--size--)--+-------------------------+-' +-NULL--'--null_string--'-+ '-NOT NULL----------------'
Element | Description | Restrictions | Syntax |
---|---|---|---|
column | One column name for each column of the external table | For each column, you must specify a built-in data type | Identifier |
data_type | Data type of the column | The data_type can be any data type supported by Informix®. | Data Type |
template | Existing table with the same schema as the external table | Cannot be a subset of columns nor differ in any column data type | Database Object Name |
size | Column size in bytes. Default is 1. | Integer; 1 ≤ size ≤ 32,767 | Literal Number |
null_string | Value to represent NULL | See Defining NULL Values. | Quoted String |