# QBColumns ## Overview `QBColumns` represents a collection of columns within a datasource, providing access to all columns for building query components such as select and where clauses. Individual columns can be accessed through `QBColumn` for more granular control over data expressions, such as sorting, conditions, and aggregations. For further details on accessing all columns, see [QBTableClause.columns](https://docs.servoy.com/reference/servoycore/dev-api/database-manager/qbtableclause#columns). For working with specific columns, refer to [QBColumn](https://docs.servoy.com/reference/servoycore/dev-api/database-manager/qbcolumn). *** --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://docs.servoy.com/reference/servoycore/dev-api/database-manager/qbcolumns.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.