Android SQLite 更新表无返回

Question

• When First Insert data it Works
• But When I update Query it doesn't work

Here is my code what I'm trying to do.

fun updateData(mData: Data) {
            if (!databaseOpen) {
                database = INSTANCE.writableDatabase
                databaseOpen = true
            }
  val values = ContentValues()

values.put(DatabaseConstan.USER_ID, mData.userId)
values.put(DatabaseConstan.ABOUT, mData.userInfo.about)


return database.update(DatabaseConstan.DATABASE_TABEL, values, "${DatabaseConstan.USER_ID}=${mData.userId}", null);

But this method works

 return  database.execSQL("UPDATE data SET userId=${mData.userId} WHERE id='1'");

Here is Create Table Command

 val QUERY_CREATE = "CREATE TABLE  $DATABASE_TABEL ($ROW_ID INTEGER PRIMARY KEY AUTOINCREMENT, $USER_ID INTEGER , $ABOUT TEXT)"

I'm confused and trying but con't understand

Answer 1

The mData object contains the new values of 3 columns that you want to replace the old values.
So mData.userId contains the new userId that does not exist in the table.
This makes the WHERE clause of the UPDATE statement, which is the 3d argument of the method update() : "${DatabaseConstan.USER_ID}=${mData.userId}" to return nothing.

So instead of ${mData.userId} you must use the original value of the column which you must save in a variable like currentUserId and change to:

"${DatabaseConstan.USER_ID}=$currentUserId"

Or maybe you want to set the WHERE clause so you search by id and not by userId and assuming that the mData object contains the id also:

"${DatabaseConstan.ID}=${mData.Id}"

Change the names of the variables to your actual names.