In E-R modeling, which symbol is used to set up relationships between two or more entities?

In E-R (Entity-Relationship) modeling, the symbol used to set up relationships between two or more entities is a diamond. Here's how it works:

1. Identify the entities: These are the objects or concepts that are part of the system you are modeling. They are represented by rectangles.

2. Identify the relationships: These are the ways in which the entities interact with each other. They are represented by diamonds.

3. Draw a line from each entity to the diamond that represents the relationship. This shows that the entities are connected.

4. Inside the diamond, you can write the nature of the relationship.

So, in summary, in E-R modeling, a diamond is used to set up relationships between two or more entities.