if_you_can_please_do的博客

controller获取的参数（e.g params.name）会自动去除字符串两端的空白字符。保存操作def user = User.get(id) if(!user.save()) { //保存失败 user.errors.allErrors.each { //打印错误提示信息 println it } } else { //保存成功 }

设置时间转换格式 JSON.registerObjectMarshaller(Date) { return it?.format("yyyy-MM-dd HH:mm:ss") } 输出pojo的指定字段 JSON.registerObjectMarshaller(User) { user -> return [

Config.groovy 配置 grails.gorm.default.constraints = { ‘*’(nullable: true) } Domainclass ClassRoom { String name static hasMany = [students: Student] //不设置这个的话,删除班级时如果存在学生数据，会因为学生的约束而删除失败

1.查询记录个数 String hql = "select count(1) from User where username like :username" long count = (Long) User.executeQuery(hql, [username: "%${username}%"]).get(0) 2.查询id集合 def hql = "select id fr