我创建了一个包含3个表的数据库：名称，描述和复选框。当我尝试插入数据时，我得到一个异常，即我的数据库不存在或表缺失。我肯定知道数据库在那里，我不确定表列是怎么回事。 我有这样的帮助类：
public class DBHelper extends SQLiteOpenHelper {
public static final String DATABASE_NAME ="ItemManager";
public static final String TABLE_NAME = "Todo";
public static final String COLUMN_ID = "id";
public static final String ITEM_NAME = "name";
public static final String DESCRIPTION = "description";
public static final String COMPLETE = "complete";
public HashMap hp;
public DBHelper(Context context){
super(context,DATABASE_NAME,null,1);
}
@Override
public void onCreate(SQLiteDatabase db) {
db.execSQL("create table Todo " +
"(id integer primary key, name text, description text, complete text)"
);
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
db.execSQL("DROP TABLE IF EXISTS Todo");
onCreate(db);
}
public boolean insertItem(String name, String description, String complete){
SQLiteDatabase db = this.getWritableDatabase();
ContentValues content = new ContentValues();
content.put("name",name);
content.put("description",description);
content.put("complete", complete);
db.insert("Todo", null, content);
return true;
}
public Cursor getData(int id){
SQLiteDatabase db = this.getReadableDatabase();
Cursor res = db.rawQuery("select * from Todo where id ="+id+"",null);
return res;
}
public int numberOfRows(){
SQLiteDatabase db = this.getReadableDatabase();
int numRows = (int) DatabaseUtils.queryNumEntries(db, TABLE_NAME);
return numRows;
}
public boolean updateItem(Integer id, String name, String description, String complete)
{
SQLiteDatabase db = this.getWritableDatabase();
ContentValues contentValues = new ContentValues();
contentValues.put("name", name);
contentValues.put("description", description);
contentValues.put("complete", complete);
db.update("Todo", contentValues, "id = ? ", new String[] { Integer.toString(id) } );
return true;
}
public Integer deleteItem(Integer id)
{
SQLiteDatabase db = this.getWritableDatabase();
return db.delete("Todo",
"id = ? ",
new String[] { Integer.toString(id) });
}
public ArrayList<ItemsHolder> getAllItems()
{
ArrayList<ItemsHolder> array_list = new ArrayList<>();
//hp = new HashMap();
SQLiteDatabase db = this.getReadableDatabase();
Cursor res = db.rawQuery("select * from Todo", null);
while(res.moveToNext()){
ItemsHolder itemsHolder = new ItemsHolder();
itemsHolder.item= res.getString(res.getColumnIndex(ITEM_NAME));
itemsHolder.Id = res.getInt(res.getColumnIndex(COLUMN_ID));
array_list.add(itemsHolder);
}
return array_list;
}
}
和DisplayActivity.java
public class DsiplayItems extends AppCompatActivity {
private DBHelper mydb;
TextView name,description;
TextView complete;
int id_To_Update = 0;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_dsiplay_items);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
name = (TextView) findViewById(R.id.editTextName);
description = (TextView) findViewById(R.id.editTextDescription);
complete = (EditText) findViewById(R.id.checkBox);
final Button btnSave = (Button) findViewById(R.id.button);
name.addTextChangedListener(new TextWatcher() {
@Override
public void onTextChanged(CharSequence s, int start, int before, int count) {
if(s.toString().trim().length()==0){
btnSave.setEnabled(false);
} else {
btnSave.setEnabled(true);
}
}
@Override
public void beforeTextChanged(CharSequence s, int start, int count,
int after) {
// TODO Auto-generated method stub
}
@Override
public void afterTextChanged(Editable s) {
// TODO Auto-generated method stub
}
});
description.addTextChangedListener(new TextWatcher() {
@Override
public void onTextChanged(CharSequence s, int start, int before, int count) {
if(s.toString().trim().length()==0){
btnSave.setEnabled(false);
} else {
btnSave.setEnabled(true);
}
}
@Override
public void beforeTextChanged(CharSequence s, int start, int count,
int after) {
// TODO Auto-generated method stub
}
@Override
public void afterTextChanged(Editable s) {
// TODO Auto-generated method stub
}
});
complete.addTextChangedListener(new TextWatcher() {
@Override
public void onTextChanged(CharSequence s, int start, int before, int count) {
if(s.toString().trim().length()==0){
btnSave.setEnabled(false);
} else {
btnSave.setEnabled(true);
}
}
@Override
public void beforeTextChanged(CharSequence s, int start, int count,
int after) {
// TODO Auto-generated method stub
}
@Override
public void afterTextChanged(Editable s) {
// TODO Auto-generated method stub
}
});
mydb = new DBHelper(this);
Bundle extras = getIntent().getExtras();
if(extras != null){
int Values = extras.getInt("id");
if(Values > 0){
Cursor re = mydb.getData(Values);
id_To_Update=Values;
re.moveToFirst();
String nam = re.getString(re.getColumnIndex(DBHelper.ITEM_NAME));
String des = re.getString(re.getColumnIndex(DBHelper.DESCRIPTION));
String com = re.getString(re.getColumnIndex(DBHelper.COMPLETE));
if (!re.isClosed())
{
re.close();
}
Button b = (Button)findViewById(R.id.button);
b.setVisibility(View.INVISIBLE);
name.setText((CharSequence)nam);
name.setFocusable(false);
name.setClickable(false);
description.setText((CharSequence)des);
description.setFocusable(false);
description.setClickable(false);
complete.setText((CharSequence)com);
complete.setFocusable(false);
complete.setClickable(false);
}
}
}
public boolean isChecked(){
return true;
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
Bundle extras = getIntent().getExtras();
if(extras !=null)
{
int Value = extras.getInt("id");
if(Value>0){
getMenuInflater().inflate(R.menu.display_items, menu);
}
else{
getMenuInflater().inflate(R.menu.main_menu, menu);
}
}
return true;
}
public boolean onOptionsItemSelected(MenuItem item)
{
super.onOptionsItemSelected(item);
switch(item.getItemId())
{
case R.id.Edit_Contact:
Button b = (Button)findViewById(R.id.button);
b.setVisibility(View.VISIBLE);
name.setEnabled(true);
name.setFocusableInTouchMode(true);
name.setClickable(true);
description.setEnabled(true);
description.setFocusableInTouchMode(true);
description.setClickable(true);
complete.setEnabled(true);
complete.setFocusableInTouchMode(true);
complete.setClickable(true);
return true;
case R.id.Delete_Contact:
android.app.AlertDialog.Builder builder = new android.app.AlertDialog.Builder(this);
builder.setMessage(R.string.deleteContact)
.setPositiveButton(R.string.yes, new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
mydb.deleteItem(id_To_Update);
Toast.makeText(getApplicationContext(), "Deleted Successfully", Toast.LENGTH_SHORT).show();
Intent intent = new Intent(getApplicationContext(),MainActivity.class);
startActivity(intent);
}
})
.setNegativeButton(R.string.no, new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
// User cancelled the dialog
}
});
android.app.AlertDialog d = builder.create();
d.setTitle("Are you sure");
d.show();
return true;
default:
return super.onOptionsItemSelected(item);
}
}
public void run(View view)
{
Bundle extras = getIntent().getExtras();
if(extras !=null)
{
int Value = extras.getInt("id");
if(Value>0){
if(mydb.updateItem(id_To_Update, name.getText().toString(), description.getText().toString(), complete.getText().toString())){
Toast.makeText(getApplicationContext(), "Updated", Toast.LENGTH_SHORT).show();
Intent intent = new Intent(getApplicationContext(),MainActivity.class);
startActivity(intent);
}
else{
Toast.makeText(getApplicationContext(), "not Updated", Toast.LENGTH_SHORT).show();
}
}
else{
if(mydb.insertItem(name.getText().toString(), description.getText().toString(), complete.getText().toString())){
Toast.makeText(getApplicationContext(), "done", Toast.LENGTH_SHORT).show();
}
else{
Toast.makeText(getApplicationContext(), "not done", Toast.LENGTH_SHORT).show();
}
Intent intent = new Intent(getApplicationContext(),MainActivity.class);
startActivity(intent);
}
}
}
}
我正在接受这个
“插入名称时出错= grr description = ert complete = ComplerrtedTask android.database.sqlite.SQLiteException：table Todo没有名为name（code 1）的列:,编译时：INSERT INTO Todo（名称，描述，完整）VALUES（？，？，？） ################################################## ############### 错误代码：1（SQLITE_ERROR） 引起：SQL（查询）错误或缺少数据库。 （表Todo没有列名为name（代码1）:,编译时：INSERT INTO Todo（名称，描述，完整）VALUES（？，？，？））“exception。
我做错了什么？今天我已经多次重建这次没有成功