test: 测试 count 查询优化。

mybatis-flex-test/mybatis-flex-spring-boot-test/src/test/java/com/mybatisflex/test/common/MapperUtilTest.java

@@ -0,0 +1,48 @@
+/*
+ *  Copyright (c) 2022-2023, Mybatis-Flex (fuhai999@gmail.com).
+ *  <p>
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *  <p>
+ *  http://www.apache.org/licenses/LICENSE-2.0
+ *  <p>
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+
+package com.mybatisflex.test.common;
+
+import com.mybatisflex.core.query.QueryWrapper;
+import com.mybatisflex.core.util.MapperUtil;
+import org.junit.jupiter.api.Test;
+
+import static com.mybatisflex.test.model.table.RoleTableDef.ROLE;
+import static com.mybatisflex.test.model.table.UserRoleTableDef.USER_ROLE;
+import static com.mybatisflex.test.model.table.UserTableDef.USER;
+
+/**
+ * @author 王帅
+ * @since 2023-06-09
+ */
+class MapperUtilTest {
+
+    @Test
+    void testOptimizeCountQueryWrapper() {
+        QueryWrapper queryWrapper = QueryWrapper.create()
+                .select(USER.USER_ID, USER.USER_NAME, ROLE.ALL_COLUMNS)
+                .from(USER.as("u"))
+                .leftJoin(USER_ROLE).as("ur").on(USER_ROLE.USER_ID.eq(USER.USER_ID))
+                .leftJoin(ROLE).as("r").on(USER_ROLE.ROLE_ID.eq(ROLE.ROLE_ID))
+                .where(USER.USER_ID.eq(3))
+                .and(USER_ROLE.ROLE_ID.eq(6))
+                .groupBy(ROLE.ROLE_ID);
+        System.out.println(queryWrapper.toSQL());
+        System.out.println(MapperUtil.rawCountQueryWrapper(queryWrapper).toSQL());
+        System.out.println(MapperUtil.optimizeCountQueryWrapper(queryWrapper).toSQL());
+    }
+
+}