当我在 Kotlin 中使用 Anko 时，如何为 SQLite 的 table 定义一个非空字段？

Question

希望在Kotlin中使用Anko时为SQLite的table定义一个not null字段

但是DBRecordTable.Category to TEXT NOT NULL是错误的，我该如何解决？

代码

  implementation "org.jetbrains.anko:anko-sqlite:$anko_version"

  override fun onCreate(db: SQLiteDatabase) {
        db.createTable( DBRecordTable.TableNAME , true,
            DBRecordTable._ID to INTEGER + PRIMARY_KEY+ AUTOINCREMENT,
            DBRecordTable.Category to TEXT NOT NULL,    //It's wrong
            DBRecordTable.Content to TEXT,
            DBRecordTable.IsFavorite to INTEGER  +DEFAULT("0"),
            DBRecordTable.IsProtected to INTEGER  +DEFAULT("0"),
            DBRecordTable.CreatedDate to INTEGER
        )
    }

Answer 1

通过查看sqlTypes.kt我们可以发现not null约束定义如下：

val NOT_NULL: SqlTypeModifier = SqlTypeModifierImpl("NOT NULL")

所以你的代码应该是：

override fun onCreate(db: SQLiteDatabase) {
    db.createTable( DBRecordTable.TableNAME , true,
        DBRecordTable._ID to INTEGER + PRIMARY_KEY + AUTOINCREMENT,
        DBRecordTable.Category to TEXT + NOT_NULL,
        DBRecordTable.Content to TEXT,
        DBRecordTable.IsFavorite to INTEGER + DEFAULT("0"),
        DBRecordTable.IsProtected to INTEGER + DEFAULT("0"),
        DBRecordTable.CreatedDate to INTEGER
    )
}

Answer 2

我们使用了这些代码行并且效果很好 table created

private val dbName = THE_PATH +"JSANotes.db"
private val dbTable = "Notes"
private val colId = "Id"
private val colTitle = "Title"
private val colContent = "Content"
private val dbVersion = 1

private val CREATE_TABLE_SQL = "CREATE TABLE IF NOT EXISTS " + dbTable + " (" + colId + " INTEGER PRIMARY KEY," + colTitle + " TEXT, " + colContent + " TEXT NOT NULL);"
private var db: SQLiteDatabase? = null

init {
    val dbHelper = DatabaseHelper(context)
    db = dbHelper.writableDatabase
}

该站点将帮助解决很多 SQLite 问题LINK

我们不使用 NOT NULL 我们用这个代替 NOT NULL

            if(edtContent.text.toString().equals("")){
            error("ENTER Content")
            edtContent.requestFocus()
            return@setOnClickListener
        }

您还可以使用此代码

测试 Activity 底部文本视图中错误消息显示的长度

        fun error(msg:String){
        object : CountDownTimer(4000, 1000) {
            override fun onTick(millisUntilFinished: Long) {
                tvError.visibility = View.VISIBLE
                tvError.setText(msg)
            }
            override fun onFinish() {
                tvError.visibility = View.INVISIBLE
                tvError.setText("")
            }
        }.start()
    }

当我在 Kotlin 中使用 Anko 时，如何为 SQLite 的 table 定义一个非空字段？

How to define a not null field for a table of SQLite when I use Anko in Kotlin?

android

kotlin

android-sqlite

anko