QUERY

Default: none

This parameter enables you to select a subset of rows from a set of tables when doing a table mode export. The value of the query parameter is a string that contains a WHERE clause for a SQL SELECT statement that will be applied to all tables (or table partitions) listed in the TABLES parameter.

For example, if user scott wants to export only those employees whose job title is SALESMAN and whose salary is less than 1600, then he could do the following (this example is UNIX-based):

exp scott TABLES=emp QUERY=\"WHERE job=\'SALESMAN\' and sal \<1600\"

Note:

Because the value of the QUERY parameter contains blanks, most operating systems require that the entire string WHERE job=\'SALESMAN\' and sal\<1600 be placed in double quotation marks or marked as a literal by some method. Operating system reserved characters also need to be preceded by an escape character. See your Oracle operating system-specific documentation for information about special and reserved characters on your system.

When executing this query, Export builds a SQL SELECT statement similar to the following:

SELECT * FROM emp WHERE job='SALESMAN' and sal <1600;

The values specified for the QUERY parameter are applied to all tables (or table partitions) listed in the TABLES parameter. For example, the following statement will unload rows in both emp and bonus that match the query:

exp scott TABLES=emp,bonus QUERY=\"WHERE job=\'SALESMAN\' and sal\<1600\"

Again, the SQL statements that Export executes are similar to the following:

SELECT * FROM emp WHERE job='SALESMAN' and sal <1600;

SELECT * FROM bonus WHERE job='SALESMAN' and sal <1600;

If a table is missing the columns specified in the QUERY clause, then an error message will be produced, and no rows will be exported for the offending table.

Restrictions When Using the QUERY Parameter

  • The QUERY parameter cannot be specified for full, user, or tablespace-mode exports.

  • The QUERY parameter must be applicable to all specified tables.

  • The QUERY parameter cannot be specified in a direct path Export (DIRECT=y)

  • The QUERY parameter cannot be specified for tables with inner nested tables.

  • You cannot determine from the contents of the export file whether the data is the result of a QUERY export.