我正在使用登录应用程序，用户应该可以登录。但是我收到此错误：
java.sql.SQLException: [SQLITE_ERROR] SQL error or missing database (near "Name": syntax error)
这就是我的代码的样子：
saveTButton.addEventHandler(ActionEvent.ACTION, (e)-> {
try
{
String query = "insert into TeachersInfo (First Name,Last Name,UserName,Password) values (?,?,?,?)";
PreparedStatement pst = connectionUsers.prepareStatement(query);
//First question mark = 1, second = 2, etc.
pst.setString(1,nameSignupTTextField.getText());
pst.setString(2,lastnameSignupTTextField.getText());
pst.setString(3,usernameSignupTTextField.getText());
pst.setString(4,passwordSignupTTextField.getText());
pst.execute();
System.out.println("Data saved");
//after executing the query this lines will close the connection with the database
pst.close();
}
catch(Exception a)
{
System.out.println(a);
}
});
代码应保存用户在数据库中输入的信息。我不知道是什么问题所以我真的很感激帮助。提前谢谢..
答案 0 :(得分：0)
由于您的列名称包含空格，您应该将它们转义：
public class BackgroundTask extends AsyncTask<String,Void,String>
{
private Context context;
private Activity activity;
private String reg_url = "http://blaah.com/register.php";
private String login_url = "http://blaah.com/login.php";
private AlertDialog.Builder builder;
private ProgressDialog progressDialog;
public BackgroundTask(Context context)
{
this.context = context;
activity = (Activity) context;
}
@Override
protected void onPreExecute()
{
builder = new AlertDialog.Builder(activity);
progressDialog = new ProgressDialog(context);
progressDialog.setTitle("Please wait");
progressDialog.setMessage("Connecting to Server...");
progressDialog.setIndeterminate(true);
progressDialog.setCancelable(false);
progressDialog.show();
}
@Override
protected String doInBackground(String... params)
{
String method = params[0];
if (method.equals("register"))
{
try
{
URL url = new URL(reg_url);
HttpURLConnection httpURLConnection = (HttpURLConnection) url.openConnection();
httpURLConnection.setRequestMethod("POST");
httpURLConnection.setDoOutput(true);
httpURLConnection.setDoInput(true);
OutputStream outputStream = httpURLConnection.getOutputStream();
BufferedWriter bufferedWriter = new BufferedWriter(new OutputStreamWriter(outputStream, "UTF-8"));
String name = params[1];
String email = params[2];
String username = params[3];
String password = params[4];
String data = URLEncoder.encode("name", "UTF-8") + "=" + URLEncoder.encode(name, "UTF-8") + "&" +
URLEncoder.encode("email", "UTF-8") + "=" + URLEncoder.encode(email, "UTF-8") + "&" +
URLEncoder.encode("password", "UTF-8") + "=" + URLEncoder.encode(password, "UTF-8");
bufferedWriter.write(data);
bufferedWriter.flush();
bufferedWriter.close();
outputStream.close();
InputStream inputStream = httpURLConnection.getInputStream();
BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(inputStream));
StringBuilder stringBuilder = new StringBuilder();
String line = "";
while ((line = bufferedReader.readLine()) != null)
{
stringBuilder.append(line).append("\n");
}
httpURLConnection.disconnect();
Thread.sleep(8000);
return stringBuilder.toString().trim();
} catch (MalformedURLException e)
{
e.printStackTrace();
} catch (IOException e)
{
e.printStackTrace();
} catch (InterruptedException e)
{
e.printStackTrace();
}
}
else if (method.equals("login"))
{
try
{
URL url = new URL(login_url);
HttpURLConnection httpURLConnection = (HttpURLConnection) url.openConnection();
httpURLConnection.setRequestMethod("POST");
httpURLConnection.setDoOutput(true);
httpURLConnection.setDoInput(true);
OutputStream outputStream = httpURLConnection.getOutputStream();
BufferedWriter bufferedWriter = new BufferedWriter(new OutputStreamWriter(outputStream, "UTF-8"));
String username,password;
username = params[1];
password = params [2];
String data = URLEncoder.encode("email", "UTF-8") + "=" + URLEncoder.encode(username, "UTF-8") + "&" +
URLEncoder.encode("password", "UTF-8") + "=" + URLEncoder.encode(password, "UTF-8");
bufferedWriter.write(data);
bufferedWriter.flush();
bufferedWriter.close();
outputStream.close();
InputStream inputStream = httpURLConnection.getInputStream();
BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(inputStream));
StringBuilder stringBuilder = new StringBuilder();
String line = "";
while ((line = bufferedReader.readLine()) != null)
{
stringBuilder.append(line + "\n");
}
httpURLConnection.disconnect();
Thread.sleep(5000);
return stringBuilder.toString().trim();
} catch (MalformedURLException e)
{
e.printStackTrace();
} catch (ProtocolException e)
{
e.printStackTrace();
} catch (UnsupportedEncodingException e)
{
e.printStackTrace();
} catch (IOException e)
{
e.printStackTrace();
} catch (InterruptedException e)
{
e.printStackTrace();
}
}
return null;
}
@Override
protected void onProgressUpdate(Void... values)
{
super.onProgressUpdate(values);
}
@Override
protected void onPostExecute(String json)
{
try
{
progressDialog.dismiss();
Log.v("JSON", json);
JSONObject jsonObject = new JSONObject(json);
JSONArray jsonArray = jsonObject.getJSONArray("server_response");
JSONObject jsonobject = jsonArray.getJSONObject(0);
String code = jsonobject.getString("code");
String message = jsonobject.getString("message");
if(code.equals("reg_true"))
{
showDialog("Sucessful registration.Thank you.Enjoy_AS!", message, code);
}
else if (code.equals("reg_false"))
{
showDialog("User Already exists", message, code);
}
else if (code.equals("login_true"))
{
Toast.makeText(context, "You are logged in", Toast.LENGTH_LONG).show();
Intent intent = new Intent(activity, SplashScreen.class);
activity.startActivity(intent);
} else if (code.equals("login_false"))
{
showDialog("Login Error", message, code);
}
} catch (JSONException e){
e.printStackTrace();
}
}
public void showDialog(String title,String message,String code)
{
builder.setTitle(title);
if (code.equals("reg_true") || code.equals("reg_false"))
{
builder.setMessage(message);//message form server
builder.setPositiveButton("OK", new DialogInterface.OnClickListener()
{
@Override
public void onClick(DialogInterface dialog, int which)
{
dialog.dismiss();
activity.finish();
}
});
}
else if (code.equals("login_false"))
{
builder.setMessage(message);
builder.setPositiveButton("OK", new DialogInterface.OnClickListener()
{
@Override
public void onClick(DialogInterface dialog, int which)
{
EditText loginEmail, loginPassword;
loginEmail = (EditText) activity.findViewById(R.id.email);
loginPassword = (EditText) activity.findViewById(R.id.password);
loginEmail.setText("");
loginPassword.setText("");
dialog.dismiss();
}
});
}
AlertDialog alertDialog = builder.create();
alertDialog.show();
}
}
请参阅此主题：Read data from sqlite where column name contains spaces in android
答案 1 :(得分：0)
我不确定sql lite中的表列中是否允许空符号。但你可以试试这个：
insert into TeachersInfo ([First Name],[Last Name],UserName,Password) values (?,?,?,?)
否则尝试编辑列名称。
答案 2 :(得分：0)
我认为问题是列名First Name和Last Name中的空格。如果那些真的是列名，我想你必须正确引用它们。但最好不要在列名中使用空格。
答案 3 :(得分：0)
不要在列名中使用空格。
try
{
String query = "insert into TeachersInfo (First_Name,Last_Name,UserName,Password) values (?,?,?,?)";
PreparedStatement pst = connectionUsers.prepareStatement(query);
//First question mark = 1, second = 2, etc.
pst.setString(1,nameSignupTTextField.getText());
pst.setString(2,lastnameSignupTTextField.getText());
pst.setString(3,usernameSignupTTextField.getText());
pst.setString(4,passwordSignupTTextField.getText());
pst.execute();
System.out.println("Data saved");
//after executing the query this lines will close the connection with the database
pst.close();
}
catch(Exception a)
{
System.out.println(a);
}
});