Question

尝试在SQLite数据库中保存数据时出错。我的应用程序有两个EditText字段，当用户点击“保存”时，输入的数据必须保存在数据库中。

我正在使用android studio 3.0.1。贝娄是我得到的错误：

16:13:01.270 12710-12710/com.vysh.gridlayoutmanagerrecyclerview 
E/SQLiteLog: (1) no such table: myTable
02-03 16:13:01.277 12710-12710/com.vysh.gridlayoutmanagerrecyclerview 
E/SQLiteDatabase: Error inserting Password=123 Name=luane

android.database.sqlite.SQLiteException: no such table: myTable (code 
1): , while compiling: INSERT INTO myTable(Password,Name) VALUES (?,?)

at 
android.database.sqlite.SQLiteConnection.nativePrepareStatement(Native 
Method)

当用户点击“保存”按钮时，将调用方法insertData（）。贝娄是包含这种方法的类：

import android.content.ContentValues;
import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.widget.Toast;

class MyDbAdapter {
    MyDbHelper helper;

    public MyDbAdapter(Context context)
    {
        helper = new MyDbHelper(context);
    }

public long insertData(String name, String password)
{
    SQLiteDatabase db = helper.getWritableDatabase();
    ContentValues contentValues = new ContentValues();
    contentValues.put(MyDbHelper.NAME, name);
    contentValues.put(MyDbHelper.PASSWORD, password);
    long id = db.insert(MyDbHelper.TABLE_NAME, null , contentValues);
    //Toast.makeText(context, message, Toast.LENGTH_LONG).show();
    return id;
}

static class MyDbHelper extends SQLiteOpenHelper {
    private static final String DATABASE_NAME = "myDatabase";
    private static final String TABLE_NAME = "myTable";
    private static final int DATABASE_Version = 1;
    private static final String UID="_id";
    private static final String NAME = "Name";
    private static final String PASSWORD= "Password";
    private static final String CREATE_TABLE = "CREATE TABLE "+TABLE_NAME +
            "( "+UID+" INTEGER PRIMARY KEY AUTOINCREMENT ," +NAME+ "VARCHAR(225)" + PASSWORD+"VARCHAR(225));";
    // private static final String DROP_TABLE ="DROP TABLE IF EXISTS "+TABLE_NAME;
    private Context context;

    public MyDbHelper(Context context) {
        super(context, DATABASE_NAME, null, DATABASE_Version);
        this.context=context;
        Message.message(context,"Started...");
    }

    @Override
    public void onCreate(SQLiteDatabase db) {
        try {

            db.execSQL(CREATE_TABLE);
            Message.message(context,"TABLE CREATED");
        } catch (Exception e) {
            Message.message(context,""+e);
        }
      }
    }// end of MyDbHelper
}

欢迎任何帮助

Answer 1

您在列名和列类型之间省略了空格。这将导致由于语法错误（列名不能包含 ( ）而未创建表。）

在您单击“保存”按钮之前未检测到此原因的原因是，在调用getReabableDatabase或getWriteableDatabase之前，不会创建/打开数据库。

你应该改变： -

private static final String CREATE_TABLE = "CREATE TABLE "+TABLE_NAME +
            "( "+UID+" INTEGER PRIMARY KEY AUTOINCREMENT ," +NAME+ "VARCHAR(225)" + PASSWORD+"VARCHAR(225));";

类似于： -

private static final String CREATE_TABLE = "CREATE TABLE "+TABLE_NAME +
            "( "+UID+" INTEGER PRIMARY KEY AUTOINCREMENT ," +NAME+ " VARCHAR(225)" + PASSWORD+" VARCHAR(225));";

请注意，您需要在进行更改后删除应用程序的数据或卸载应用程序，以便删除数据库，从而允许运行onCreate方法。

在SQLite中创建数据库时出错

1 个答案: