I faced a problem while working with android studio and SQLite as the backend database. I have created two tables as follows:
DB.execSQL("create Table patients(userid INTEGER PRIMARY KEY AUTOINCREMENT, username Text Not Null, P_fname Text, P_lname Text)");
DB.execSQL("create Table assistant (id INTEGER, a_fname Text, a_lname Text,FOREIGN KEY (id) REFERENCES patients(userid) ON DELETE CASCADE)");
and I used this insert method for the assistant information:
public Boolean insertData(int id, String a_fname, String a_lname) {
SQLiteDatabase DB = this.getWritableDatabase();
ContentValues contentValues = new ContentValues();
contentValues.put("id", id);
contentValues.put("a_fname", a_fname);
contentValues.put("a_lname", a_lname);
long result = DB.insert("assistant ", null, contentValues);
if (result == -1) return false;
else
return true;
}
both the patient and the personal assistant are supposed to share the same id, but I couldn't be able to do it.
question from:
https://stackoverflow.com/questions/65914648/how-to-solve-foreign-key-problem-in-android 与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…