添加MySQL配置，并跑通项目

backend/.idea/encodings.xml

@@ -2,6 +2,7 @@
 <project version="4">
   <component name="Encoding" defaultCharsetForPropertiesFiles="UTF-8">
     <file url="file://$PROJECT_DIR$/src/main/java" charset="UTF-8" />
+    <file url="file://$PROJECT_DIR$/src/main/resources" charset="UTF-8" />
     <file url="PROJECT" charset="UTF-8" />
   </component>
 </project>

backend/.idea/misc.xml

@@ -1,6 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project version="4">
-  <component name="ExternalStorageConfigurationManager" enabled="true" />
   <component name="MavenProjectsManager">
     <option name="originalFiles">
       <list>