feat: 添加SQL初始化文件和自动填充处理器

src/main/java/com/example/building/config/MybatisPlusMetaObjectHandler.java

@@ -0,0 +1,25 @@
+package com.example.building.config;
+
+import com.baomidou.mybatisplus.core.handlers.MetaObjectHandler;
+import org.apache.ibatis.reflection.MetaObject;
+import org.springframework.stereotype.Component;
+
+import java.time.LocalDateTime;
+
+/**
+ * MyBatis Plus 自动填充处理器
+ */
+@Component
+public class MybatisPlusMetaObjectHandler implements MetaObjectHandler {
+
+    @Override
+    public void insertFill(MetaObject metaObject) {
+        this.strictInsertFill(metaObject, "createdAt", LocalDateTime.class, LocalDateTime.now());
+        this.strictInsertFill(metaObject, "updatedAt", LocalDateTime.class, LocalDateTime.now());
+    }
+
+    @Override
+    public void updateFill(MetaObject metaObject) {
+        this.strictUpdateFill(metaObject, "updatedAt", LocalDateTime.class, LocalDateTime.now());
+    }
+}