在 Yii 2.0 中，一张关联表中的一个字段分别被两张表同时关联的实现

1、栏目配置：pa_config_column，如图1

图1

2、栏目人员配置：pa_config_column_user，如图2

图2

3、选题：pa_plan，如图3

图3

4、选题任务：pa_plan_task，如图4

图4

5、任务管理 – 我的任务，查询规则
(1)任务的租户ID为当前登录用户的租户ID；
(2)栏目配置未删除；
(3)选题未删除；
(4)选题任务未删除；
(5)选题任务的执行用户ID(`pa_plan_task`.`exec_user_id`)为当前登录用户ID && 栏目人员配置未删除 || 选题创建用户ID(`pa_plan`.`create_user_id`)为当前登录用户ID && 栏目人员配置未删除 || (栏目人员配置租户ID为当前登录用户租户ID && 栏目人员配置角色标识包含栏目负责人标识 && && 栏目人员配置未删除)；

6、现在的查询规则，需求在于，主表为 选题任务：pa_plan_task，其需要关联表 选题：pa_plan；选题任务：pa_plan_task 需要关联表 栏目人员配置：pa_config_column_user，基于 `pa_plan_task`.`exec_user_id`；选题：pa_plan 需要关联表 栏目人员配置：pa_config_column_user，基于 `pa_plan`.`create_user_id`

7、/common/logics/PlanTask.php，声明关联关系

    public function getConfigColumn()
    {
        return $this->hasOne(ConfigColumn::className(), [ 'id' => 'config_column_id' ]);
    }

    public function getPlanById()
    {
        return $this->hasOne(Plan::className(), [ 'id' => 'plan_id' ]);
    }
    
    public function getConfigColumnUser()
    {
        return $this->hasOne(ConfigColumnUser::className(), [ 'config_column_id' => 'config_column_id', 'user_id' => 'exec_user_id' ]);
    }

8、/common/logics/Plan.php，声明关联关系

    public function getConfigColumn()
    {
        return $this->hasOne(ConfigColumn::className(), [ 'id' => 'config_column_id' ]);
    }

    public function getConfigColumnUser()
    {
        return $this->hasOne(ConfigColumnUser::className(), [ 'config_column_id' => 'config_column_id', 'user_id' => 'create_user_id' ]);
    }

9、查询代码最终如下，如果一张关联表中的一个字段分别被两张表同时关联，需要设置关联表的别名

	$query = $modelClass::find()
		->joinWith('configColumn')
		->joinWith(['configColumnUser ccue'])
		->joinWith(['planById' => function($q) {
			$q->joinWith('configColumnUser ccuc');
		}])
		->where([
			'and',
			[$modelClass::tableName() . '.group_id' => $identity->group_id],
			[ConfigColumn::tableName() . '.is_deleted' => ConfigColumn::IS_DELETED_NO],
			[Plan::tableName() . '.is_deleted' => Plan::IS_DELETED_NO],
			[$modelClass::tableName() . '.is_deleted' => $modelClass::IS_DELETED_NO]
		])
		->andWhere([
			'or',
			[
				'and',
				[$modelClass::tableName() . '.exec_user_id' => $identity->id],
				['ccue.is_deleted' => ConfigColumnUser::IS_DELETED_NO]
			],
			[
				'and',
				[Plan::tableName() . '.create_user_id' => $identity->id],
				['ccuc.is_deleted' => ConfigColumnUser::IS_DELETED_NO]
			],
			[
				'in',
				Plan::tableName() . '.config_column_id',
				$configColumnIds
			]
		])
		->orderBy([$modelClass::tableName() . '.sort_order' => SORT_ASC, $modelClass::tableName() . '.id' => SORT_DESC]);

10、最终生成的 SQL 语句如下：

SELECT `pa_plan_task`.* FROM `pa_plan_task` LEFT JOIN `pa_config_column` ON `pa_plan_task`.`config_column_id` = `pa_config_column`.`id` LEFT JOIN `pa_config_column_user` `ccue` ON `pa_plan_task`.`config_column_id` = `ccue`.`config_column_id` AND `pa_plan_task`.`exec_user_id` = `ccue`.`user_id` LEFT JOIN `pa_plan` ON `pa_plan_task`.`plan_id` = `pa_plan`.`id` LEFT JOIN `pa_config_column_user` `ccuc` ON `pa_plan`.`config_column_id` = `ccuc`.`config_column_id` AND `pa_plan`.`create_user_id` = `ccuc`.`user_id` WHERE (`pa_plan_task`.`group_id`='015ce30b116ce86058fa6ab4fea4ac63') AND (`pa_config_column`.`is_deleted`=0) AND (`pa_plan`.`is_deleted`=0) AND (`pa_plan_task`.`is_deleted`=0) AND (((`pa_plan_task`.`exec_user_id`='8') AND (`ccue`.`is_deleted`=0)) OR ((`pa_plan`.`create_user_id`='8') AND (`ccuc`.`is_deleted`=0)) OR (`pa_plan`.`config_column_id`=1)) ORDER BY `pa_plan_task`.`sort_order`, `pa_plan_task`.`id` DESC LIMIT 10