数据库助手
public class DataBaseHelper extends SQLiteOpenHelper {
public static final String DATABASE_NAME ="Glucoplate.bd";
public static final String TABLE_NAME ="User_table";
public static final String COL_1 = "ID";
public static final String COL_2 ="NAME";
public static final String COL_3 = "SURNAME";
public static final String COL_4 = "MARKS";
public DataBaseHelper(Context context) {
super(context, DATABASE_NAME, null, 1);
}
@Override
public void onCreate(SQLiteDatabase db) {
db.execSQL("CREATE TABLE" + TABLE_NAME + "(ID INTEGER PRIMARY KEY AUTOINCREMENT,NAME TEXT,SURNAME TEXT, MARKS INTEGER)");
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
db.execSQL("DROP TABLE IF EXIST "+TABLE_NAME);
}
public boolean insertData(String name, String surname, String marks){
SQLiteDatabase db = this.getWritableDatabase();
ContentValues contentValues = new ContentValues();
contentValues.put(COL_2,name);
contentValues.put(COL_3,surname);
contentValues.put(COL_4, marks);
long result = db.insert(TABLE_NAME,null,contentValues);
db.close();
if (result == -1) {
return false;
}else{
return true;
}
}
}
我遵循了 Android Academy 中的教程,但即使在构建和清理项目之后,我也不想工作。
主要活动
public class MainActivity extends AppCompatActivity {
DataBaseHelper myDb;
EditText txtName, txtSurname, txtMarks;
Button btnClick;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
myDb= new DataBaseHelper(this);
txtName = (EditText) findViewById(R.id.idName);
txtSurname = (EditText) findViewById(R.id.idSurname);
txtMarks =(EditText) findViewById(R.id.idMarks);
btnClick = (Button) findViewById(R.id.idBtn);
btnClick.setOnClickListener(new View.OnClickListener(){
@Override
public void onClick(View v){
ClickMe();
}
});
}
private void ClickMe(){
String name= txtName.getText().toString();
String surname = txtSurname.getText().toString();
String marks = txtMarks.getText().toString();
Boolean result= myDb.insertData(name, surname, marks);
if(result == true){
Toast.makeText(this, "agragado", Toast.LENGTH_SHORT).show();
}else{
Toast.makeText(this,"Fallo",Toast.LENGTH_SHORT).show();
}
}
}
我正在使用 android Nougat
,我尝试了另外 4 种方法,但仍然无效;此外,该 ID 不会显示任何错误、警告或任何它只是崩溃的内容。
根据您的代码和堆栈跟踪,您没有" "
在CREATE TABLE
和之间添加空格TABLE_NAME
。添加" "
后TABLE_NAME
了。
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