Question

关于SQlite插入数据不显示的问题

package sqliteshuju;

import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteDatabase.CursorFactory;
import android.database.sqlite.SQLiteOpenHelper;

public class sqlitetext extends SQLiteOpenHelper{

private static final int VERSION =1;

public sqlitetext(Context context, String name, CursorFactory factory,
int version) {
super(context, name, factory, version);
// TODO Auto-generated constructor stub
}
public sqlitetext(Context context, String name){

this(context,name, VERSION);
}
public sqlitetext(Context context,String name,int version){

this(context,name,null,VERSION);
}

@Override
public void onCreate(SQLiteDatabase db) {
// TODO Auto-generated method stub
db.execSQL("Create table user(id int,name varchar(20))");
}

@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
// TODO Auto-generated method stub platform-
System.out.println("ssss");

}

}
-----------------------------------------
public class Youxi6Activity extends Activity {

private Button chuangjian=null;
private Button charu=null;
private TextView text=null;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);

chuangjian=(Button)findViewById(R.id.chuangjian);
charu=(Button)findViewById(R.id.charu);
text=(TextView)findViewById(R.id.ceshi);
chuangjian.setOnClickListener(new chuangjianshujuku());
charu.setOnClickListener(new charushuju());
}
class chuangjianshujuku implements OnClickListener{

public void onClick(View v) {
// TODO Auto-generated method stub
sqlitetext st=new sqlitetext(Youxi6Activity.this,"sqlshujuku");
SQLiteDatabase db=st.getReadableDatabase();
}

}
class charushuju implements OnClickListener{

public void onClick(View v) {
// TODO Auto-generated method stub
ContentValues cv=new ContentValues();
cv.put("id", 1);
cv.put("name", "yuandaw");
sqlitetext st=new sqlitetext(Youxi6Activity.this,"sqlshujuku");
SQLiteDatabase db=st.getWritableDatabase();
db.insert("user", null, cv);
text.setText("yuandaw");
}

}

}
在cmd中select * from user 后 什么也不显示

Answer 1

首先我说下，我用了你的代码。是可以运行的，而且我也查看了数据库user表内容，成功插入了。首先我有几点不明白：
1.为什么你要单独创建数据库？ SQLiteDatabase db=st.getWritableDatabase(); 数据库不存在的话会自动创建。创建的是多余的代码。
2.建议在用完数据库的时候关闭数据库。db.close();
不知道是不是你查询的方法有些问题。你再试试，或者你直接点击“插入数据的按钮”

附上查看数据库命令：
adb shell
sqlite3 data/data/sqliteshuju/databases/sqlshujuku
.table
select * from user ;