1. 完成 menu 模块的迁移

2. 增加 mybatis plus 的 QueryWrapperX 封装，方便拼接 SQL

src/main/java/cn/iocoder/dashboard/framework/mybatis/core/dataobject/BaseDO.java

@@ -1,4 +1,4 @@
-package cn.iocoder.dashboard.framework.mybatis.core;
+package cn.iocoder.dashboard.framework.mybatis.core.dataobject;
 
 import com.baomidou.mybatisplus.annotation.TableLogic;
 import lombok.Data;

src/main/java/cn/iocoder/dashboard/framework/mybatis/core/query/QueryWrapperX.java

@@ -0,0 +1,93 @@
+package cn.iocoder.dashboard.framework.mybatis.core.query;
+
+import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
+import com.baomidou.mybatisplus.core.toolkit.ArrayUtils;
+import com.baomidou.mybatisplus.core.toolkit.CollectionUtils;
+import org.springframework.util.StringUtils;
+
+import java.util.Collection;
+
+/**
+ * 拓展 MyBatis Plus QueryWrapper 类，主要增加如下功能：
+ *
+ * 1. 拼接条件的方法，增加 xxxIfPresent 方法，用于判断值不存在的时候，不要拼接到条件中。
+ *
+ * @param <T> 数据类型
+ */
+public class QueryWrapperX<T> extends QueryWrapper<T> {
+
+    public QueryWrapperX<T> likeIfPresent(String column, String val) {
+        if (StringUtils.hasText(val)) {
+            return (QueryWrapperX<T>) super.like(column, val);
+        }
+        return this;
+    }
+
+    public QueryWrapperX<T> inIfPresent(String column, Collection<?> values) {
+        if (!CollectionUtils.isEmpty(values)) {
+            return (QueryWrapperX<T>) super.in(column, values);
+        }
+        return this;
+    }
+
+    public QueryWrapperX<T> inIfPresent(String column, Object... values) {
+        if (!ArrayUtils.isEmpty(values)) {
+            return (QueryWrapperX<T>) super.in(column, values);
+        }
+        return this;
+    }
+
+    public QueryWrapperX<T> eqIfPresent(String column, Object val) {
+        if (val != null) {
+            return (QueryWrapperX<T>) super.eq(column, val);
+        }
+        return this;
+    }
+
+    public QueryWrapperX<T> gtIfPresent(String column, Object val) {
+        if (val != null) {
+            return (QueryWrapperX<T>) super.gt(column, val);
+        }
+        return this;
+    }
+
+    public QueryWrapperX<T> betweenIfPresent(String column, Object val1, Object val2) {
+        if (val1 != null && val2 != null) {
+            return (QueryWrapperX<T>) super.between(column, val1, val2);
+        }
+        if (val1 != null) {
+            return (QueryWrapperX<T>) ge(column, val1);
+        }
+        if (val2 != null) {
+            return (QueryWrapperX<T>) le(column, val2);
+        }
+        return this;
+    }
+
+    // ========== 重写父类方法，方便链式调用 ==========
+
+    @Override
+    public QueryWrapperX<T> eq(boolean condition, String column, Object val) {
+        super.eq(condition, column, val);
+        return this;
+    }
+
+    @Override
+    public QueryWrapperX<T> eq(String column, Object val) {
+        super.eq(column, val);
+        return this;
+    }
+
+    @Override
+    public QueryWrapperX<T> orderByDesc(String column) {
+        super.orderByDesc(true, column);
+        return this;
+    }
+
+    @Override
+    public QueryWrapperX<T> last(String lastSql) {
+        super.last(lastSql);
+        return this;
+    }
+
+}