I am new to databases and wanted to know with what software the following database schema visualisation has been generated.
我是数据库新手,想知道使用哪种软件已生成以下数据库模式可视化。
In particular, what are the different types of keys/fields that are represented by the various symbols.
特别地,由各种符号表示的键/字段的不同类型是什么。