# Many-to-Many {% hint style="warning" %} Having too many relationship properties ***(especially many-to-many)*** on a single collection definitely degrades performance in Adalo, especially at scale. {% endhint %} ## Learn About Many-to-Many Relationships {% embed url="" %} *** #### **Many-to-Many Relationship** A many-to-many relationship exists when records in one collection can be connected to multiple records in another collection, and vice versa. #### **Example: Tasks and Users** * One task can be assigned to multiple users **AND** One user can be assigned to multiple tasks {% hint style="danger" %} * **M-M Relationships can not be added on creation of new record in database.** * **M-M Relationships can not be set upon Create Action for new record.** {% endhint %} *** ## **Relationships vs Join Collections** Relationships are essential for organizing data in Adalo, but they come with performance trade-offs. Understanding the difference between direct relationships and junction collections allows you to make informed decisions about your data structure. * **Use relationships** for simple, one-to-many connections and small datasets * **Use junction collections** when possible for many-to-many relationships and before number of relationships to any single collection becomes an issue * **Plan ahead:** Choose your data structure with growth in mind --- # 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://help.adalo.com/database/relationships/many-to-many.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.