ORA-01789

ORA-01789 query block has incorrect number of result columns

What causes an ORA-01789 error?

All of the queries participating in a set expression do not contain the same number of SELECT list columns.

How Xynomix can help

Check that all the queries in the set expression have the same number of SELECT list columns.

Contact us for more information. To learn more about ways we can support your database visit our Oracle database consultancy page.

Contact Us



    On submitting this form, Xynomix will store your details and may contact you in relation to your request. For more information on how we process data, please see our privacy notice.

    “We have utilised Xynomix consultancy for multiple projects. Most recently we have enlisted their consultants help to complete an Oracle database migration to new servers. As part of this Xynomix used their specialist knowledge to set up an appropriate backup and data retention policy in line with industry best practice. The work was, as always, completed in a timely, efficient manner.”
    aston university