Tips on exporting data with the UNLOAD statement

The UNLOAD statement is similar to the OUTPUT statement in that they both export query results to a file. However, the UNLOAD statement exports data more efficiently in a text format. The UNLOAD statement exports with one row per line, with values separated by a comma delimiter.

Use the UNLOAD statement to unload data when you want to:

export query results if performance is an issue
store output in text format
embed an export statement in an application
export data to a file on a client computer

To use the UNLOAD statement with a SELECT, you must have the appropriate privileges. For example, the SELECT ANY TABLE system privilege is usually sufficient, unless the -gl database server option is set to NONE. At minimum, you must have the permissions required to execute the SELECT on the table that is specified within the UNLOAD statement

For more information about who can use the UNLOAD statement, see -gl database server option.

Impact on the database

Example

Using the SQL Anywhere sample database, you can unload a subset of the Employees table to a text file named GAEmployees.csv by executing the following statement:

UNLOAD 
SELECT * FROM Employees 
WHERE State = 'GA'
TO 'C:\\ServerTemp\\GAEmployees.csv'
QUOTE '"';

Using this form of the UNLOAD TABLE statement, the file path is relative to the database server computer.