Java SQLite项目中的语法错误，can'；我找不到他
我首先尝试使用SQLite，我有语法错误，但我在5-6个小时内找不到他 来自MainActivity.java的代码，在这个类中我称之为数据库：Java SQLite项目中的语法错误，can'；我找不到他,java,android,sqlite,Java,Android,Sqlite,我首先尝试使用SQLite，我有语法错误，但我在5-6个小时内找不到他 来自MainActivity.java的代码，在这个类中我称之为数据库： package ua.bellkross.notepadjava; import android.content.ContentValues; import android.content.SharedPreferences; import android.database.Cursor; import android.database.sqlite
package ua.bellkross.notepadjava;
import android.content.ContentValues;
import android.content.SharedPreferences;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.EditText;
public class MainActivity extends AppCompatActivity {
EditText editText;
DatabaseHelper databaseHelper;
SQLiteDatabase db;
Cursor userCursor;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
editText = (EditText) findViewById(R.id.editText);
databaseHelper = new DatabaseHelper(getApplicationContext());
}
@Override
protected void onResume() {
super.onResume();
db = databaseHelper.getWritableDatabase();
userCursor = db.rawQuery("select * from " + DatabaseHelper.TABLE, null);
editText.setText(userCursor.getString(userCursor.getColumnIndex(DatabaseHelper.COLUMN_NAME)));
}
}
package ua.bellkross.notepadjava;
import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
public class DatabaseHelper extends SQLiteOpenHelper {
private static final String DATABASE_NAME = "userstore.db"; // название бд
private static final int SCHEMA = 1; // версия базы данных
static final String TABLE = "table"; // название таблицы в бд
// названия столбцов
public static final String COLUMN_ID = "_id";
public static final String COLUMN_NAME = "name";
public DatabaseHelper(Context context) {
super(context, DATABASE_NAME, null, SCHEMA);
}
@Override
public void onCreate(SQLiteDatabase db) {
db.execSQL("CREATE TABLE users (" + COLUMN_ID
+ " INTEGER PRIMARY KEY AUTOINCREMENT, " + COLUMN_NAME + " TEXT);");
// добавление начальных данных
db.execSQL("INSERT INTO "+ TABLE +"(" + COLUMN_NAME + ") VALUES ('Text');");
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
db.execSQL("DROP TABLE IF EXISTS "+TABLE);
onCreate(db);
}
}
“table”是保留的关键字。请将表名更改为任何非保留SQL关键字。您正在使用
表static final String TABLE = "users"
您正在使用命名用户创建一个表
db.execSQL("CREATE TABLE users (" + COLUMN_ID
+ " INTEGER PRIMARY KEY AUTOINCREMENT, " + COLUMN_NAME + " TEXT);");
db.execSQL("INSERT INTO "+ TABLE +"(" + COLUMN_NAME + ") VALUES ('Text');");
static final String TABLE = "users";
db.execSQL("CREATE TABLE "+ TABLE +"(" + COLUMN_ID
+ " INTEGER PRIMARY KEY AUTOINCREMENT, " + COLUMN_NAME + " TEXT);");