SQL去重：如何使用DISTINCT关键字去除重复数据

SELECT permission_tbl.id,permission_tbl.name\nFROM user_tbl\nJOIN user_role ON user_tbl.id = user_role.user_id\nJOIN role_tbl ON user_role.role_id = role_tbl.id\nJOIN role_permission ON role_tbl.id = role_permission.role_id\nJOIN permission_tbl ON role_permission.permission_id = permission_tbl.id\nWHERE user_tbl.id = '82' ;\n这条sql查出来的结果有重复的数据怎么去重内容：要去除重复的数据，可以使用DISTINCT关键字。将SELECT语句改为：\n\nSELECT DISTINCT permission_tbl.id, permission_tbl.`name`\nFROM user_tbl\nJOIN user_role ON user_tbl.id = user_role.user_id\nJOIN role_tbl ON user_role.role_id = role_tbl.id\nJOIN role_permission ON role_tbl.id = role_permission.role_id\nJOIN permission_tbl ON role_permission.permission_id = permission_tbl.id\nWHERE user_tbl.id = '82';\n\n这样就会去除重复的数据，只返回唯一的数据。