title: ContentValues Insert always return the -1
body: <p><code>db.insert(table_name,null,contentValues);</code> is always returning <code>-1</code> and it is not inserting the values in the databases. </p>
  
  <p>Can you please help me to figure out what I'm doing the wrong?</p>
  
  <p>database_class.java:</p>
  
  <pre><code>public class database_class extends SQLiteOpenHelper {
      public static final String database_name = "signup_db";
      public static final String table_name = "signup";
      public static final String column_1 = "FIRST_NAME";
      public static final String column_2 = "SECOND_NAME";
      public static final String column_3 = "EMAIL";
      public static final String column_4 = "PASSWORD";
      public static final String column_5 = "c_password";
  
      public database_class(Context context){
          super(context,database_name , null, 1);
          //Toast.makeText(context, "Class called ", Toast.LENGTH_SHORT).show();
  
      }
  
      @Override
      public void onCreate(SQLiteDatabase db) {
          db.execSQL("create table" + table_name + "(ID INTEGER PRIMARY KEY AUTOINCREMENT , FIRST_NAME TEXT , SECOND_NAME TEXT , EMAIL TEXT , PASSWORD TEXT)");
      }
  
      @Override
      public void onUpgrade(SQLiteDatabase db, int i, int i1) {
          db.execSQL("DROP TABLE IF EXISTS" + table_name);
          onCreate(db);
      }
      public boolean insertData(String first_name, String second_name, String email, String password){
          SQLiteDatabase db = this.getWritableDatabase();
          ContentValues contentValues = new ContentValues();
          contentValues.put(column_1,first_name);
          contentValues.put(column_2,second_name);
          contentValues.put(column_3,email);
          contentValues.put(column_4,password);
          long result = db.insert(table_name,null,contentValues);
          if (result == -1)
              return false;
          else
              return true;
  
      }
  }
  </code></pre>
  
  <p>MainActivity Code:</p>
  
  <pre><code>fn = editText1.getText().toString();
  ln = editText2.getText().toString();
  em = editText3.getText().toString();
  pass = editText4.getText().toString();
  cpass = editText5.getText().toString();
  
  if (1 == 1) {
      //boolean isInserted =  mydb.insertData(signup_values[0].toString(),signup_values[1].toString(),signup_values[2].toString(),signup_values[3].toString());
      boolean isInserted =  mydb.insertData(fn,ln,em,pass);
      if(isInserted == true) {
          Toast.makeText(MainActivity.this, "Data Inserted", Toast.LENGTH_SHORT).show();
      }
      else
          Toast.makeText(MainActivity.this, "Data not Inserted", Toast.LENGTH_SHORT).show();
  }
  else
      Toast.makeText(MainActivity.this, "Password Mismatch", Toast.LENGTH_SHORT).show();
  </code></pre>