增加兼容属性配置.

spring-boot-starter/mybatis-plus-spring-boot-autoconfigure/src/main/java/com/baomidou/mybatisplus/autoconfigure/MybatisPlusProperties.java

@@ -335,10 +335,15 @@ public class MybatisPlusProperties {
          */
         private Properties variables;
 
-        // 新增兼容开始...
+        // 新增兼容开始... mybatis 3.x 的有做属性删减  部分属性在2.x可用 3.x 已经被剔除了.
+        /**
+         * Specifies the language used by default for dynamic SQL generation.
+         */
         private Class<? extends LanguageDriver> defaultScriptingLanguageDriver;
 
-        protected String databaseId;
+        private String databaseId;
+        
+        private Boolean useGeneratedShortKey;
 
         public void applyTo(Configuration target) {
             PropertyMapper mapper = PropertyMapper.get().alwaysApplyingWhenNonNull();
@@ -375,6 +380,7 @@ public class MybatisPlusProperties {
             mapper.from(getDefaultEnumTypeHandler()).to(target::setDefaultEnumTypeHandler);
             mapper.from(getDefaultScriptingLanguageDriver()).to(target::setDefaultScriptingLanguage);
             mapper.from(getDatabaseId()).to(target::setDatabaseId);
+            mapper.from(getUseGeneratedShortKey()).to(target::setUseGeneratedKeys);
         }
     }