无法将数据插入 android studio sqlite 数据库
Unable to insert data into android studio sqlite database
我目前正在做一个学校项目，试图创建一个送餐服务并且需要一个 signup/login 数据库。但是 creating/inserting 将数据导入数据库时遇到了麻烦。该应用程序没有崩溃，但 Toast 消息告诉我“注册失败”。
从错误日志来看，我似乎能够创建 table，但无法将数据插入 table。
如果有人能给我一些建议，我将不胜感激。
DatabaseHelper.java
public class DatabaseHelper extends SQLiteOpenHelper {
public static final String DATABASE_NAME = " mylist.db ";
public static final String TABLE_NAME = " mylist ";
public static final String USER_NAME = " username ";
public static final String EMAIL = " email ";
public static final String PHONE_NUMBER = " phone ";
public static final String PASSWORD = " password ";
public DatabaseHelper(Context context) {
super(context, DATABASE_NAME, null, 1);
}
//CREATING THE DATABASE TABLE
@Override
public void onCreate(SQLiteDatabase sqLiteDatabase) {
String createTable;
createTable = "CREATE TABLE " + TABLE_NAME +
" ( ID INTEGER PRIMARY KEY AUTOINCREMENT, "+
USER_NAME + " username " +
EMAIL + " email ," +
PHONE_NUMBER + " phone ,"+
PASSWORD + " password ) ";
sqLiteDatabase.execSQL(createTable);
}
@Override
public void onUpgrade(SQLiteDatabase sqLiteDatabase, int i, int i1) {
sqLiteDatabase.execSQL("DROP TABLE IF EXISTS " + TABLE_NAME);
}
public boolean addData(String username, String email, String phone, String password){
SQLiteDatabase sqLiteDatabase = this.getWritableDatabase();
ContentValues contentValues = new ContentValues();
contentValues.put(USER_NAME, username);
contentValues.put(EMAIL, email);
contentValues.put(PHONE_NUMBER, phone);
contentValues.put(PASSWORD, password);
long result = sqLiteDatabase.insert(TABLE_NAME, null, contentValues);
if (result == -1) return false;
else {return true;}
}
}
错误日志
E/SQLiteLog: (1) table mylist has no column named email
E/SQLiteDatabase: Error inserting phone = email = password = username =j
android.database.sqlite.SQLiteException: table mylist has no column named email (code 1): , while compiling: INSERT INTO mylist ( phone , email , password , username ) VALUES (?,?,?,?)
at android.database.sqlite.SQLiteConnection.nativePrepareStatement(Native Method)
at android.database.sqlite.SQLiteConnection.acquirePreparedStatement(SQLiteConnection.java:890)
at android.database.sqlite.SQLiteConnection.prepare(SQLiteConnection.java:501)
at android.database.sqlite.SQLiteSession.prepare(SQLiteSession.java:588)
at android.database.sqlite.SQLiteProgram.<init>(SQLiteProgram.java:58)
at android.database.sqlite.SQLiteStatement.<init>(SQLiteStatement.java:31)
at android.database.sqlite.SQLiteDatabase.insertWithOnConflict(SQLiteDatabase.java:1546)
at android.database.sqlite.SQLiteDatabase.insert(SQLiteDatabase.java:1417)
at com.example.doonfood.DatabaseHelper.addData(DatabaseHelper.java:45)
at com.example.doonfood.signuppage.ADDDATA(signuppage.java:33)
at com.example.doonfood.signuppage.Signup(signuppage.java:48)
at java.lang.reflect.Method.invoke(Native Method)
at androidx.appcompat.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:409)
at android.view.View.performClick(View.java:6294)
at com.google.android.material.button.MaterialButton.performClick(MaterialButton.java:992)
at android.view.View$PerformClick.run(View.java:24770)
at android.os.Handler.handleCallback(Handler.java:790)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:164)
at android.app.ActivityThread.main(ActivityThread.java:6494)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:438)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:807)
signuppage.java
public class signuppage extends AppCompatActivity {
DatabaseHelper myDB;
EditText SignupUserName;
EditText SignupEMail;
EditText SignupPhoneNumber;
EditText SignupPassword;
Button SignupBtn;
@Override
protected void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.signuppage);
myDB = new DatabaseHelper(this);
SignupUserName = findViewById(R.id.SignupUserName);
SignupEMail = findViewById(R.id.SignupEMail);
SignupPhoneNumber = findViewById(R.id.SignupPhoneNumber);
SignupPassword = findViewById(R.id.SignupPassword);
SignupBtn = findViewById(R.id.SignupBtn);
}
public void ADDDATA(String newUSER, String newEMAIL, String newPHONE, String newPASSWORD){
boolean insertData = myDB.addData(newUSER, newEMAIL, newPHONE, newPASSWORD);
if (insertData == true){
Toast.makeText(signuppage.this, "Sign up successful.", Toast.LENGTH_SHORT).show();
}else {
Toast.makeText(signuppage.this, "Sign up unsuccessful.", Toast.LENGTH_SHORT).show();
}
}
public void Signup(View view) {
String newUSER, newEMAIL, newPHONE, newPASSWORD;
newUSER = SignupUserName.getText().toString();
newEMAIL = SignupEMail.getText().toString();
newPHONE = SignupPhoneNumber.getText().toString();
newPASSWORD = SignupPassword.getText().toString();
if ((SignupUserName.length() != 0) || (SignupEMail.length() != 0) || (SignupPhoneNumber.length() != 0) || (SignupPassword.length() != 0)) {
ADDDATA(newUSER, newEMAIL, newPHONE, newPASSWORD);
SignupUserName.setText(newUSER);
SignupEMail.setText(newEMAIL);
SignupPhoneNumber.setText(newPHONE);
SignupPassword.setText(newPASSWORD);
} else {
Toast.makeText(signuppage.this, "Text Field cannot be empty.", Toast.LENGTH_SHORT).show();
}
}
}
首先数据库名不需要写.db
在onCreate()中这样写
String query = "Create table if not exists " + TABLE_NAME + " (UESR_NAME, EMAIL, PHONE_NUMBER,PASSWORD)";
db.execSQL(query);
创建一个在 table 中插入数据的方法，如下所示：
public void insertData(String userName, String email, String phoneNumber, String password)
{
SQLiteDatabase db = getWritableDatabase();
ContentValues values = new ContentValues();
values.put("USER_NAME", userName);
values.put("EMAIL", email);
values.put("PHONE_NUMBER",phoneNumber);
values.put("PASSWORD",password);
db.insert(TABLE_NAME,null,values);
db.close();
}
首先，删除 db/table/columns:
的变量定义中的前导空格和尾随空格
public static final String DATABASE_NAME = "mylist.db";
public static final String TABLE_NAME = "mylist";
public static final String ID = "ID"; // I added this definition
public static final String USER_NAME = "username";
public static final String EMAIL = "email";
public static final String PHONE_NUMBER = "phone";
public static final String PASSWORD = "password";
然后，修复 table 的 CREATE 语句，其中没有定义列的数据类型，而是使用了它们的名称两次，并且还遗漏了中间的逗号：
createTable = "CREATE TABLE " + TABLE_NAME + "(" +
ID + " INTEGER PRIMARY KEY AUTOINCREMENT, " +
USER_NAME + " TEXT," +
EMAIL + " TEXT," +
PHONE_NUMBER + " TEXT," +
PASSWORD + " TEXT)";
进行这些更改后，您必须从设备上卸载该应用程序，以便删除数据库并重新运行以重新创建数据库和 table。
我目前正在做一个学校项目，试图创建一个送餐服务并且需要一个 signup/login 数据库。但是 creating/inserting 将数据导入数据库时遇到了麻烦。该应用程序没有崩溃，但 Toast 消息告诉我“注册失败”。
从错误日志来看，我似乎能够创建 table，但无法将数据插入 table。
如果有人能给我一些建议，我将不胜感激。
DatabaseHelper.java
public class DatabaseHelper extends SQLiteOpenHelper {
public static final String DATABASE_NAME = " mylist.db ";
public static final String TABLE_NAME = " mylist ";
public static final String USER_NAME = " username ";
public static final String EMAIL = " email ";
public static final String PHONE_NUMBER = " phone ";
public static final String PASSWORD = " password ";
public DatabaseHelper(Context context) {
super(context, DATABASE_NAME, null, 1);
}
//CREATING THE DATABASE TABLE
@Override
public void onCreate(SQLiteDatabase sqLiteDatabase) {
String createTable;
createTable = "CREATE TABLE " + TABLE_NAME +
" ( ID INTEGER PRIMARY KEY AUTOINCREMENT, "+
USER_NAME + " username " +
EMAIL + " email ," +
PHONE_NUMBER + " phone ,"+
PASSWORD + " password ) ";
sqLiteDatabase.execSQL(createTable);
}
@Override
public void onUpgrade(SQLiteDatabase sqLiteDatabase, int i, int i1) {
sqLiteDatabase.execSQL("DROP TABLE IF EXISTS " + TABLE_NAME);
}
public boolean addData(String username, String email, String phone, String password){
SQLiteDatabase sqLiteDatabase = this.getWritableDatabase();
ContentValues contentValues = new ContentValues();
contentValues.put(USER_NAME, username);
contentValues.put(EMAIL, email);
contentValues.put(PHONE_NUMBER, phone);
contentValues.put(PASSWORD, password);
long result = sqLiteDatabase.insert(TABLE_NAME, null, contentValues);
if (result == -1) return false;
else {return true;}
}
}
错误日志
E/SQLiteLog: (1) table mylist has no column named email
E/SQLiteDatabase: Error inserting phone = email = password = username =j
android.database.sqlite.SQLiteException: table mylist has no column named email (code 1): , while compiling: INSERT INTO mylist ( phone , email , password , username ) VALUES (?,?,?,?)
at android.database.sqlite.SQLiteConnection.nativePrepareStatement(Native Method)
at android.database.sqlite.SQLiteConnection.acquirePreparedStatement(SQLiteConnection.java:890)
at android.database.sqlite.SQLiteConnection.prepare(SQLiteConnection.java:501)
at android.database.sqlite.SQLiteSession.prepare(SQLiteSession.java:588)
at android.database.sqlite.SQLiteProgram.<init>(SQLiteProgram.java:58)
at android.database.sqlite.SQLiteStatement.<init>(SQLiteStatement.java:31)
at android.database.sqlite.SQLiteDatabase.insertWithOnConflict(SQLiteDatabase.java:1546)
at android.database.sqlite.SQLiteDatabase.insert(SQLiteDatabase.java:1417)
at com.example.doonfood.DatabaseHelper.addData(DatabaseHelper.java:45)
at com.example.doonfood.signuppage.ADDDATA(signuppage.java:33)
at com.example.doonfood.signuppage.Signup(signuppage.java:48)
at java.lang.reflect.Method.invoke(Native Method)
at androidx.appcompat.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:409)
at android.view.View.performClick(View.java:6294)
at com.google.android.material.button.MaterialButton.performClick(MaterialButton.java:992)
at android.view.View$PerformClick.run(View.java:24770)
at android.os.Handler.handleCallback(Handler.java:790)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:164)
at android.app.ActivityThread.main(ActivityThread.java:6494)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:438)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:807)
signuppage.java
public class signuppage extends AppCompatActivity {
DatabaseHelper myDB;
EditText SignupUserName;
EditText SignupEMail;
EditText SignupPhoneNumber;
EditText SignupPassword;
Button SignupBtn;
@Override
protected void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.signuppage);
myDB = new DatabaseHelper(this);
SignupUserName = findViewById(R.id.SignupUserName);
SignupEMail = findViewById(R.id.SignupEMail);
SignupPhoneNumber = findViewById(R.id.SignupPhoneNumber);
SignupPassword = findViewById(R.id.SignupPassword);
SignupBtn = findViewById(R.id.SignupBtn);
}
public void ADDDATA(String newUSER, String newEMAIL, String newPHONE, String newPASSWORD){
boolean insertData = myDB.addData(newUSER, newEMAIL, newPHONE, newPASSWORD);
if (insertData == true){
Toast.makeText(signuppage.this, "Sign up successful.", Toast.LENGTH_SHORT).show();
}else {
Toast.makeText(signuppage.this, "Sign up unsuccessful.", Toast.LENGTH_SHORT).show();
}
}
public void Signup(View view) {
String newUSER, newEMAIL, newPHONE, newPASSWORD;
newUSER = SignupUserName.getText().toString();
newEMAIL = SignupEMail.getText().toString();
newPHONE = SignupPhoneNumber.getText().toString();
newPASSWORD = SignupPassword.getText().toString();
if ((SignupUserName.length() != 0) || (SignupEMail.length() != 0) || (SignupPhoneNumber.length() != 0) || (SignupPassword.length() != 0)) {
ADDDATA(newUSER, newEMAIL, newPHONE, newPASSWORD);
SignupUserName.setText(newUSER);
SignupEMail.setText(newEMAIL);
SignupPhoneNumber.setText(newPHONE);
SignupPassword.setText(newPASSWORD);
} else {
Toast.makeText(signuppage.this, "Text Field cannot be empty.", Toast.LENGTH_SHORT).show();
}
}
}
首先数据库名不需要写.db
在onCreate()中这样写
String query = "Create table if not exists " + TABLE_NAME + " (UESR_NAME, EMAIL, PHONE_NUMBER,PASSWORD)"; db.execSQL(query);创建一个在 table 中插入数据的方法，如下所示：
public void insertData(String userName, String email, String phoneNumber, String password) { SQLiteDatabase db = getWritableDatabase(); ContentValues values = new ContentValues(); values.put("USER_NAME", userName); values.put("EMAIL", email); values.put("PHONE_NUMBER",phoneNumber); values.put("PASSWORD",password); db.insert(TABLE_NAME,null,values); db.close(); }
首先，删除 db/table/columns:
的变量定义中的前导空格和尾随空格public static final String DATABASE_NAME = "mylist.db";
public static final String TABLE_NAME = "mylist";
public static final String ID = "ID"; // I added this definition
public static final String USER_NAME = "username";
public static final String EMAIL = "email";
public static final String PHONE_NUMBER = "phone";
public static final String PASSWORD = "password";
然后，修复 table 的 CREATE 语句，其中没有定义列的数据类型，而是使用了它们的名称两次，并且还遗漏了中间的逗号：
createTable = "CREATE TABLE " + TABLE_NAME + "(" +
ID + " INTEGER PRIMARY KEY AUTOINCREMENT, " +
USER_NAME + " TEXT," +
EMAIL + " TEXT," +
PHONE_NUMBER + " TEXT," +
PASSWORD + " TEXT)";
进行这些更改后，您必须从设备上卸载该应用程序，以便删除数据库并重新运行以重新创建数据库和 table。