Mysql sql查询时 if 的用法 MySQLSQLPHPUnixBlog

SELECT qanswers.id,qanswers.question_id,qanswers.answer,users.nickname AS replier,

users.groupname,IF(users.groupname='teacher',TRUE,FALSE) AS isTeacher

FROM fa_user_question_answer AS qanswers 

LEFT JOIN fa_users AS users ON users.id=qanswers.user_id 

WHERE qanswers.question_id=11