每Annotate indices and uniqueness,似乎可以添加如下所示的唯一约束,
但在AndroidStudio 3中出现错误(编辑器有红色下划线表示“未解析参考:索引”),:
.navbar-light .navbar-nav .nav-link {
color: red;
}
如何在使用kotlin时在字段上添加唯一约束?
gradle就像:/Users/application/database/DbAuthor.kt
Error:(14, 39) Expecting an element
@Entity(tableName = "author" indices = arrayOf(Index(value = "authorid", unique = true)))
class DbAuthor(
@ColumnInfo(name = "authorid")
var authorid: Int? = null,
和
buildscript {
ext {
verAndroidSupport = '27.0.0'
arch = "1.0.0"
archRoomVersion = "1.0.0"
}
ext.kotlin_version = '1.2.20'
答案 0 :(得分:8)
,
后你错过了"author"
@Entity(tableName = "author", indices = arrayOf(Index(value = "authorid", unique = true)))