Question

// IN CONTENT PROVIDER

public int delete(Uri uri, String selection, String[] selectionArgs) {

            int uriType = sURIMatcher.match(uri);
            SQLiteDatabase sqlDB = myDB.getWritableDatabase();
            int rowsDeleted = 0;

            switch (uriType) {
            case STUDENTS:
    //          rowsDeleted = sqlDB.delete(MyDBHandler.TABLE_STUDENTS, selection,  selectionArgs);
                rowsDeleted = sqlDB.delete(MyDBHandler.TABLE_STUDENTS, selection + " ?",  new String [] {"limit 1"});


                break;
default:
            throw new IllegalArgumentException("Unknown URI: " + uri);
        }
        getContext().getContentResolver().notifyChange(uri, null);
        return rowsDeleted;
    }

IN CONTENT RESOLVER

    private ContentProviderClient myCR;
public static final Uri CONTENT_URI = Uri.parse("content://" + AUTHORITY + "/"+ STUDENT_TABLE);

        public MyDBHandler(Context context, String name, CursorFactory factory, int version) {
            super(context, DATABASE_NAME, factory, DATABASE_VERSION);
            myCR = 

context.getContentResolver().acquireContentProviderClient(CONTENT_URI);
        public boolean deleteStudent(String studentName) {  
    String selection = "sName = " + studentName +  " LIMIT 1";
        rowsDeleted = myCR.delete(CONTENT_URI, selection,null);

//also tried this
String selection = "sName = " + studentName ;
rowsDeleted = myCR.delete(CONTENT_URI.buildUpon().encodedQuery("limit 1").build(), selection,null);

有一个学生表，我正在根据名称删除条目，因为可能有许多同名学生我想限制删除功能只删除第一个条目。请不要告诉我使用学生注册号删除

Answer 1

编译到Android中的SQLite不允许LIMIT语句的DELETE子句。

您必须使用SELECT（或只读取第一个返回的记录）执行LIMIT 1，并使用返回的ID删除使用学生注册号。

在Android中的SQLiteDatabase.delete（）中传递限制1

1 个答案: