我已经使用SQlite数据库创建了一个注册活动，当我点击符号按钮时，我的应用程序中出现运行时错误.Stacktrace引导我进入我为数据库创建的DatabaseHelper类中的第36行，然后显示注册活动中的错误，但我无法解决它们。任何帮助和想法都非常有用
PS（我在Android开发和stackoverflow中的新功能很抱歉很长的帖子，也许是明显的错误 这是stacktrace
E/SQLiteLog: (1) near "contact": syntax error
06-29 17:48:21.680 5897-5897/kanepraktiki2017.xyz.mreprogramming.kanepraktiki E/AndroidRuntime: FATAL EXCEPTION: main
Process: kanepraktiki2017.xyz.mreprogramming.kanepraktiki, PID: 5897
java.lang.IllegalStateException: Could not execute method of the activity
at android.view.View$1.onClick(View.java:4240)
at android.view.View.performClick(View.java:5184)
at android.view.View$PerformClick.run(View.java:20893)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:145)
at android.app.ActivityThread.main(ActivityThread.java:5938)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1400)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1195)
Caused by: java.lang.reflect.InvocationTargetException
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at android.view.View$1.onClick(View.java:4235)
at android.view.View.performClick(View.java:5184)
at android.view.View$PerformClick.run(View.java:20893)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:145)
at android.app.ActivityThread.main(ActivityThread.java:5938)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1400)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1195)
Caused by: android.database.sqlite.SQLiteException: near "contact": syntax error (code 1): , while compiling: create contact table(id integer primary key not null , name text not null, email text not null , username text not null, password text not null);
at android.database.sqlite.SQLiteConnection.nativePrepareStatement(Native Method)
at android.database.sqlite.SQLiteConnection.acquirePreparedStatement(SQLiteConnection.java:1093)
at android.database.sqlite.SQLiteConnection.prepare(SQLiteConnection.java:670)
at android.database.sqlite.SQLiteSession.prepare(SQLiteSession.java:588)
at android.database.sqlite.SQLiteProgram.<init>(SQLiteProgram.java:59)
at android.database.sqlite.SQLiteStatement.<init>(SQLiteStatement.java:31)
at android.database.sqlite.SQLiteDatabase.executeSql(SQLiteDatabase.java:1798)
at android.database.sqlite.SQLiteDatabase.execSQL(SQLiteDatabase.java:1729)
at kanepraktiki2017.xyz.mreprogramming.kanepraktiki.DabaseHelper.onCreate(DabaseHelper.java:36)
at android.database.sqlite.SQLiteOpenHelper.getDatabaseLocked(SQLiteOpenHelper.java:251)
at android.database.sqlite.SQLiteOpenHelper.getWritableDatabase(SQLiteOpenHelper.java:163)
at kanepraktiki2017.xyz.mreprogramming.kanepraktiki.DabaseHelper.insertContact(DabaseHelper.java:41)
at kanepraktiki2017.xyz.mreprogramming.kanepraktiki.Signup.onSignUpClick(Signup.java:49)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at android.view.View$1.onClick(View.java:4235)
at android.view.View.performClick(View.java:5184)
at android.view.View$PerformClick.run(View.java:20893)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:145)
DatabaseHelper.java代码$
Public class DabaseHelper extends SQLiteOpenHelper {
private static final int DATABASE_VERSION = 1;
private static final String DATABASE_name = "contacts.db";
private static final String TABLE_name = "contacts";
private static final String COLUMN_id = "id";
private static final String COLUMN_name = "name";
private static final String COLUMN_email = "email";
private static final String COLUMN_username = "username";
private static final String COLUMN_password = "password";
SQLiteDatabase db;
private static final String TABLE_create = "create contact table(id integer primary key not null , " +
"name text not null, email text not null , username text not null, password text not null);";
public DabaseHelper(Context context) {
super(context, DATABASE_name, null, DATABASE_VERSION);
}
@Override
public void onCreate(SQLiteDatabase db) {
db.execSQL(TABLE_create);
this.db = db;
}
public void insertContact(Contact c) {
db = this.getWritableDatabase();
ContentValues values = new ContentValues();
String query="select * from contacts";
Cursor cursor=db.rawQuery(query, null);
int count=cursor.getCount();
values.put(COLUMN_id, count);
values.put(COLUMN_name, c.getName());
values.put(COLUMN_email, c.getEmail());
values.put(COLUMN_username, c.getUsername());
values.put(COLUMN_password, c.getPassword());
db.insert(DATABASE_name, null, values);
db.close();
}
public String searchpass(String username) {
db = this.getReadableDatabase();
String query = "select username, password from" + TABLE_name;
Cursor cursor = db.rawQuery(query, null);
String a, b;
b = "Δεν βρέθηκε";
if (cursor.moveToFirst()) {
do {
a = cursor.getString(0);
if (a.equals(username)) {
b = cursor.getString(1);
break;
}
}
while (cursor.moveToNext());
}
return b;
}
@Override
public void onUpgrade(SQLiteDatabase db, int i, int i1) {
String query ="Drop Table If Exists"+TABLE_name;
db.execSQL(query);
this.onCreate(db);
}
}
答案 0 :(得分：1)
创建新表的SQL语句无效。您可以切换关键字table和表名。试试这个：
CREATE TABLE contact
(
id integer primary key not null,
name text not null,
email text not null,
username text not null,
password text not null
);
此声明中也有失败。
String query="select * from contacts";
您可以使用变量TABLE_name，但必须更改表的名称。
private static final String TABLE_name = "contact";
然后像这样更改SQL语句：
String query = "SELECT * FROM" + this.TABLE_name;
答案 1 :(得分：0)
将您的陈述改为此陈述：
"create table contact(id integer primary key not null , " +
"name text not null, email text not null , username text not null, password text not null);"
而不是“创建联系表（...）”，它应该是“创建表联系人（...）”
编辑：如果您仍然收到错误更改此行：
String query="select * from contacts";
到此：
String query="select * from contact";
此外，如果您不断收到错误，可能是因为您正在尝试重新创建已创建的表。请学习SQL，SQLite和Andriod数据库连接，以便了解它的实际工作原理。互联网研究可以帮助您理解像这些
这样的高度记录的主题