如果用户输入名称后如何显示名称，因为我还不知道如何操作并将数据插入数据库。
我想显示名称，并能够添加时间和日期闹钟。
如果用户输入名称后如何显示名称，因为我还不知道如何操作并将数据插入数据库。
我想显示名称，并能够添加时间和日期闹钟。
import android.content.DialogInterface;
import android.os.Bundle;
import android.support.design.widget.AppBarLayout;
import android.support.design.widget.TabLayout;
import android.support.v4.view.ViewPager;
import android.support.v7.app.AlertDialog;
import android.support.v7.app.AppCompatActivity;
import android.view.LayoutInflater;
import android.view.View;
import android.widget.AdapterView;
import android.widget.EditText;
import android.widget.Spinner;
import android.widget.Toast;
public class MainActivity extends AppCompatActivity implements AdapterView.OnItemSelectedListener {
private TabLayout tabLayout;
private AppBarLayout appBarLayout;
private ViewPager viewPager;
private EditText edtName;
Spinner spin1;
Spinner spin2;
Spinner spin3;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
DBHelper db = new DBHelper();
tabLayout = findViewById(R.id.tablayout);
appBarLayout = findViewById(R.id.bar);
viewPager = findViewById(R.id.viewpager);
edtName = findViewById(R.id.edtName);
spin1 = findViewById(R.id.spinnerFrequency);
spin2 = findViewById(R.id.SpinnerTime);
spin3 = findViewById(R.id.SpinnerQty);
Adapter adapter = new Adapter(getSupportFragmentManager());
/*screen*/
adapter.AddFragment(new Drugfragment(), "Drug");
adapter.AddFragment(new Appointmentfragment(), "Appointment");
viewPager.setAdapter(adapter);
tabLayout.setupWithViewPager(viewPager);
tabLayout.setupWithViewPager(viewPager);
Account c = new Account();
if(c==null) {
}else{
AlertDialog.Builder builder = new AlertDialog.Builder(MainActivity.this);
builder.setTitle("LOG IN");
LayoutInflater inflater = MainActivity.this.getLayoutInflater();
builder.setView(inflater.inflate(R.layout.account,null));
builder.setPositiveButton("Yes",new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
AlertDialog.Builder builder = new AlertDialog.Builder(MainActivity.this);
LayoutInflater inflater = MainActivity.this.getLayoutInflater();
builder.setView(inflater.inflate(R.layout.accountname,null));
builder.setPositiveButton("Yes",new DialogInterface.OnClickListener(){
public void onClick(DialogInterface dialog, int id) {
}
});
builder.show();
}
});
builder.setNegativeButton("No",new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
System.exit(0);
}
});
builder.show();
db.insertRecord();
}
}
public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
String text = parent.getItemAtPosition(position).toString();
Toast.makeText(parent.getContext(), text, Toast.LENGTH_SHORT).show();
}
@Override
public void onNothingSelected(AdapterView<?> parent) {
}
}
这是我的数据库助手
import android.content.ContentValues;
import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
/**
* Created by User on 23/5/2018.
*/
public class DBHelper extends SQLiteOpenHelper {
private static final String DATABASE_NAME="accountDB.db";
private static final String DATABASE_TABLE="Account";
private static final String COL1="AccountName";
private static final String COL2="Time";
public DBHelper(){
super(context, DATABASE_NAME, null, 1);
}
public DBHelper(Context context, String name, SQLiteDatabase.CursorFactory factory, int version) {
super(context, name, factory, version);
}
@Override
public void onCreate(SQLiteDatabase db) {
db.execSQL("create table Account(acctname text)");
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion){
db.execSQL("DROP TABLE IF EXISTS " + DATABASE_TABLE);
this.onCreate(db);
}
public void insertRecord(AccountInfo a){
SQLiteDatabase db = this.getWritableDatabase();
ContentValues contents = new ContentValues();
contents.put("AccountName", a.getAcctName());
}
}
答案 0 :(得分：0)
检索并使用存储在Android设备上的SQLiteDatabase中的数据的基本原则是使用/运行查询来 SELECT 数据，这是可以通过光标，然后在光标内移动到适当的行，最后从相应的列中提取数据。
对于您的特定问题，您希望找到最后插入的行，幸运的是SQLite有一个可以提供帮助的功能，即last_insert_rowid()
因此查询将为SELECT * FROM Account WHERE rowid = last_insert_rowid()
由于您提供的代码存在各种问题。以下是基于您的代码的示例： -
提取最后添加的帐户的名称（虽然您知道这个名称根本不是很有用）。
首先是一个非常简单的AccountInfo类，即AccountInfo.java（您已经看到它了： -
public class AccountInfo {
private String mAccountName;
public AccountInfo(String account_name) {
this.mAccountName = account_name;
}
public String getAcctName() {
return mAccountName;
}
}
第二个 DBHelper.java （注意评论，也不是与你的相似之处）： -
public class DBHelper extends SQLiteOpenHelper {
private static final String DATABASE_NAME="accountDB.db";
private static final String DATABASE_TABLE="Account";
private static final String COL1="AccountName"; //<<<< not used
private static final String COL2="Time"; //<<<< not used
public DBHelper(Context context){ //<<<< modifed to include the Context to be passed
super(context, DATABASE_NAME, null, 1);
}
//<<<<<<<<<< This is superfluous and isn't used in this example >>>>>>>>>>
//<<<<<<<<<< It could be deleted >>>>>>>>>>
public DBHelper(Context context, String name, SQLiteDatabase.CursorFactory factory, int version) {
super(context, name, factory, version);
}
@Override
public void onCreate(SQLiteDatabase db) {
db.execSQL("create table Account(acctname text)");
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion){
db.execSQL("DROP TABLE IF EXISTS " + DATABASE_TABLE);
this.onCreate(db);
}
public void insertRecord(AccountInfo a){
SQLiteDatabase db = this.getWritableDatabase();
ContentValues contents = new ContentValues();
//contents.put("AccountName", a.getAcctName()); //<<<< Will fail as incorrect column name
contents.put("acctname",a.getAcctName()); //<<<< column name as per table definition
db.insert(DATABASE_TABLE,null,contents); //<<<< ADDED to do the insert itself
}
//<<<<<<<<<< The Query that gets the name of the account last added >>>>>>>>>>
public String getLastInsertedAccountName() {
String rv = ""; //<<<< Just in case nothing is extracted set the return value to empty String
String[] columns = new String[]{"acctname"}; //<<<< The columns to extract (only one)
String whereclause = "rowid = last_insert_rowid()"; //<<<< The SQL WHERE clause (less the WHERE keyword)
SQLiteDatabase db = this.getWritableDatabase();//<<<< Get the SQLite database
// Use the SQLliteDatabase convenience query method that gets the data into a Cursor
Cursor csr = db.query(
DATABASE_TABLE, //<<<< The table to be queried (ie FROM )
columns, //<<<< The columns to be returned just one (could use null to return all columns)
whereclause, //<<<< The WHERE clause
null, //<<<< selection args (none so null)
null, //<<<< the column(s) to GROUP BY (none so null)
null, //<<<< The having clause (none so null)
null //<<<< The ORDER BY clause (none so null)
);
//<<<< Move to the first (only) row in the Cursor (if there is one)
if (csr.moveToFirst()) {
// Get the value, as a string, from the column name acctname
rv = csr.getString(
csr.getColumnIndex(
"acctname"
)
);
}
csr.close(); //<<<< Close the Cursor as done with it
return rv; //<<<< Finally retruned that extracted value
}
}
活动中的调用代码 MainActivity （非常简单）： -
公共类MainActivity扩展了AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
DBHelper mDBHlpr = new DBHelper(this); //<<<< Get an instance of the DBHelper
AccountInfo c = new AccountInfo("Fred"); //<<<< Create an Account to add
mDBHlpr.insertRecord(c);
//<<<<<<<<<< one line version of the two lines above (commented out) <<<<<<<<<<
//mDBHlpr.insertRecord(new AccountInfo("Tom"));
String account_just_inserted = mDBHlpr.getLastInsertedAccountName(); //<<<< get the name
//<<<<<<<<<< Do something with the name i.e. write it out to the Log >>>>>>>>>>
Log.d(
"ACCOUNT INSERTED",
"The Name of the account just inserted is :-" +
account_just_inserted
);
}
}
运行上面的内容将输出类似于： -
的内容05-24 09:27:14.215 1287-1287/acnta.accountapp D/ACCOUNT INSERTED: The Name of the account just inserted is :-Fred