请教这条sql语句有错吗??
有4个表
表: t_enterprise t_project t_project_apply t_declare_apply
字段 id id id id
name enterprise_id project_id enterprise_name
finished
通过t_project的enterprise_id和t_enterprise的id使t_enterprise和t_project关联 ,
通过t_project_apply的project_id 和t_project 的id使t_project 和t_project_apply关联
通过判断t_project_apply的finished字段是否为0查找到t_project,再从t_project找到t_enterprise,再选择t_enterprise的name不在t_declare_apply的enterprise_name中的t_enterprise
我写的语句是这样,可是运行出来没结果帮忙看看:
SELECT POLLUTERS.* FROM (SELECT T_ENTERPRISE.* FROM T_ENTERPRISE,(SELECT T_PROJECT.* FROM T_PROJECT,T_PROJECT_APPLY WHERE T_PROJECT.ID=T_PROJECT_APPLY.PROJECT_ID AND T_PROJECT_APPLY.FINISHED != 0) PROJECTS WHERE PROJECTS.ENTERPRISE_ID=T_ENTERPRISE.ID) POLLUTER,T_DECLARE_APPLY WHERE POLLUTER.NAME NOT IN (SELECT ENTERPISE_NAME FROM T_DECLARE_APPLY) POLLUTERS
不对的话该怎么写。