unicode symbols for entity-relationship

Question

What are the Unicode symbols that most closely relate to the symbols used in entity-relationship diagrams, such as the ones in the screenshot of the OP here: https://stackoverflow.com/questions/1755591/many-to-many-relationships-with-additional-data-on-the-relationship?

When displaying data, I want to prefix a Unicode representation of entity-relationship that its table represents.

The "many-to-one" entity relationship uses symbols that look almost like ">o-to-⧺" , respectively, but...

• the actual many symbol, like in the screenshot and in some database books, has an extra glyph that looks like a strikethrough of the ">" symbol, almost like ->, but with the - attached to the > like a 3rd prong, not separated like it is here ->.
• The actual one symbol appears to be the ⧺ (U+29fa = Double Plus) character, which I found while writing this post, but I do not know if this is the actual correct symbol, but it looks very close to it. Close enough, I guess.

I've gleaned through several Unicode charts, like this one for the many symbol, but have not found it.

Answer 1

From my experience, simpler characters are more commonly used, e.g. 1-1 to mean one-to-one, and 1-* or 1-n for one-to-many, and *-* or n-m for many-to-many.

You can also use the infinity symbol (U+221E) for the "many" symbol if you really wanted but I prefer the previous simpler examples.

By the way, that website is helpfully searchable and you can find other similar arrow characters to what you're looking for as well such as the following:

• Rightwards Two Headed Arrow (U+21A0)
• Rightwards Double Arrow (U+21D2)
• Rightwards Triple Arrow (U+21DB)
• Rightwards Arrow with Double Vertical Stroke (U+21FB)
• Rightwards Two-Headed Arrow with Double Vertical Stroke (U+2901)
• Rightwards Double Arrow-Tail (U+291C)

Answer 2

As an example: User ∋−∈ Role

from: Mathematical operators on Wikipedia