android之sqlite增删改查

public Uri insert(Uri uri, ContentValues values) {
SQLiteDatabase db=dBhelper.getWritableDatabase();
long rowid=db.insert("student",null,values);
Uri uri2= ContentUris.withAppendedId(uri,rowid);
return uri2;
}
@Override
public int delete(Uri uri, String selection, String[] selectionArgs) {
SQLiteDatabase db=dBhelper.getWritableDatabase();
selection="name=?";
selectionArgs=new String[]{"jack"};
db.delete("student",selection,selectionArgs);
return 0;
}
@Override
public int update(Uri uri, ContentValues values, String selection, String[] selectionArgs) {
SQLiteDatabase db=dBhelper.getWritableDatabase();
ContentValues contentValues=new ContentValues();
contentValues.put("name","gaojiaxin");
selection="name=?";
selectionArgs=new String[]{"mateng"};
db.update("student", contentValues, selection, selectionArgs);
return 0;
}
@Nullable
@Override
public Cursor query(Uri uri, String[] projection, String selection, String[] selectionArgs, String sortOrder) {
SQLiteDatabase db=dBhelper.getWritableDatabase();
Cursor c=db.query("student",null,null,null,null,null,null);
return c;
}

<------------------------------分隔线----------------------------------------->
测试增删改查代码如下

public void testadd(){
ContentValues values=new ContentValues();
values.put("name", "mateng");
getContext().getContentResolver().insert(contactProvider.connect_uri, values);
}
public  void testdelete(){

getContext().getContentResolver().delete(contactProvider.connect_uri, null, null);
}

public void testupdate(){
getContext().getContentResolver().update(contactProvider.connect_uri, null, null, null);
}

public void testquery(){
Cursor c=getContext().getContentResolver().query(contactProvider.connect_uri,null,null,null,null);
c.moveToFirst();
for(int i=0;i<c.getCount();i++){
c.move(i);
String name = c.getString(c.getColumnIndex("name"));
System.out.println(name);
}
}