mysql workbench支持逆向工程建模，具体操作如下：
一路next直到Finish，就可以看到生成了ER图
总体流程如下：Menu
Database->Reverse Engineer...
弹出Reverse Engineer Database对话框
Connection Options
->next
Connection to DBMS
->next
Select Schemas
选择要逆向的数据库
Select Objects
->next
Reverse Engineer
->Execute
Results
->Finish
画布大小调整：
Model->Dragiam Propertise And Size...