在运行时创建SQLite的分贝 [英] Create SQlite Db on runtime

问题描述

我想在运行时创建多个数据库。用户输入数据库名和系统必须创建它。

I am trying to create multiple databases at runtime. The user enter the database name and the system must create it.

这是我的code

First.Java

First.Java

public class First extends Activity implements OnClickListener {
    Button              btnOk;
    EditText            inputName;
    DatabaseHandler     db  = null;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.db);
        try {
            this.getWindow().setSoftInputMode(WindowManager.LayoutParams.SOFT_INPUT_STATE_ALWAYS_HIDDEN);
            initVar();
        }
        catch (Exception e) {
            CommonUtils.postException(e, e.getMessage().toString());
        }
    }

    private void initVar() {
        try {
            btnOk = (Button) findViewById(R.id.btnOk);
            inputName = (EditText) findViewById(R.id.dbName);
            btnOk.setOnClickListener(this);
        }
        catch (Exception e) {
            CommonUtils.postException(e, e.getMessage().toString());
        }
    }

    public void onClick(View v) {
        if (v == btnOk ){
        DBConstants.DATABASE_NAME=inputName.getText().toString().trim();
        Toast.makeText(getApplicationContext(), DBConstants.DATABASE_NAME, Toast.LENGTH_LONG).show();
        db = new DatabaseHandler(getApplicationContext());
        db.getmyDb();
            if(DatabaseHandler.doesDatabaseExist(getApplication(), inputName.getText().toString().trim())== true ){
                Toast.makeText(getApplicationContext(), "DB created", Toast.LENGTH_LONG).show();
                db.close();
            }else{
                Toast.makeText(getApplicationContext(), "DB Not created", Toast.LENGTH_LONG).show();
                db.close();
            }
        }
    }
}

DatabaseHandler.java

DatabaseHandler.java

public class DatabaseHandler extends SQLiteOpenHelper {

private static final int DATABASE_VERSION = 1;
private static SQLiteDatabase myDb = null;

public DatabaseHandler(Context context) {
    super(context, DBConstants.DATABASE_NAME, null, DATABASE_VERSION);
}

public SQLiteDatabase getmyDb() {
    if (myDb == null)
        myDb = this.getWritableDatabase();
    return myDb;
}

@Override
public void onCreate(SQLiteDatabase db) {
}

@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
    onCreate(db);
}

public static boolean doesDatabaseExist(ContextWrapper context, String dbName) {
    File dbFile=context.getDatabasePath(dbName);
    return dbFile.exists();
}

在OK按钮的preSS我需要创建一个由该的EditText用户输入的文本数据库

On the press of OK button I need to create a database with the text entered by the user in the EditText

目前这项工作只有一次，如果用户输入一个不同的文本第二次，数据库未创建

currently this work only once, if the user enters a different text the second time, the database is not created

推荐答案

在这一行：

private static SQLiteDatabase myDb = null;

尝试删除static修饰符 - 场被用作一个实例对象

Try removing the static modifier - the field is used as an instance object.

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