indexing

问题 I want to impement a pyramid which has different texture in each side. The pyramid with the textures is correct without using an index data array. When i use the indexdata the textures get mixed with each other. Do i have to correct the AttribPointer? (My texture is a collage image of 5 different images) *I want to keep the indexData array Here is a part of the code from OpenGL.GLUT import * from OpenGL.GLU import * from OpenGL.GL import * import numpy as np from framework import * from PIL

问题 PostgreSQL 9.5.0 I have a table called message_attachments it has 1931964 rows. There's one key that I search for in that table, that's message_id . I also, always include the deleted_at is NULL statement (e.g. soft delete). There was an index created: CREATE INDEX message_attachments_message_id_idx ON message_attachments (message_id) WHERE deleted_at IS NULL; So it should directly match this query: EXPLAIN ANALYZE select * from "message_attachments" where "deleted_at" is null and "message_id

问题 PostgreSQL 9.5.0 I have a table called message_attachments it has 1931964 rows. There's one key that I search for in that table, that's message_id . I also, always include the deleted_at is NULL statement (e.g. soft delete). There was an index created: CREATE INDEX message_attachments_message_id_idx ON message_attachments (message_id) WHERE deleted_at IS NULL; So it should directly match this query: EXPLAIN ANALYZE select * from "message_attachments" where "deleted_at" is null and "message_id

问题 I can set up the list fine and even have a select or deselect button in the detail view (CardView). The problem I encounter is when I click select I want to add it to an array (cardSelected). If "name3" is the 1st in the list how can I find out the index to add to the cardSelected array? I'm new to programming so looking for some guidance. Thanks import Foundation import SwiftUI class Cards: ObservableObject { @Published var cardSelected = [gameCards]() @Published var playerCards = [gameCards

问题 Suppose I created index with descending order CREATE INDEX `MyTable.MyIndex` USING BTREE ON `MyTable` (`DateFrom` DESC, `DateTo` DESC); I want to get information about it from information_schema . According to documentation information_schema.statistics table does the job. However I can't find any information about column order for indexes (i.e. ASC or DESC ). How can I find that information? 回答1: Where is it written in the documentation that the table statistics does the job ? Furthermore, I

问题 Your string length should be one more than the maximum number of characters you want it to be able to hold. Logical enough: strings are terminated with a NULL character. It's a very general advice that most newbies get. However, as I grew in programming, now it seems that it's not so correct. The indexing of any type of array, be it int or char , starts from 0 . The maximum index value of most arrays, therefore, is one less than its numerical value. It's same with a string, but since it has

问题 Your string length should be one more than the maximum number of characters you want it to be able to hold. Logical enough: strings are terminated with a NULL character. It's a very general advice that most newbies get. However, as I grew in programming, now it seems that it's not so correct. The indexing of any type of array, be it int or char , starts from 0 . The maximum index value of most arrays, therefore, is one less than its numerical value. It's same with a string, but since it has

问题 I have this list: list1 = [['X1',2],['X2',4],['Y1',2],['Y2',4]] and I want to create this dict: dict1 = {'X': {'1':2},{'2':4},'Y':{'1':2},{'2':4}} so that I can use dict1['X']['1'] and this outputs '2' Can someone help me out? I've tried multiple approaches but without any success. 回答1: You can use collections.defaultdict : >>> from collections import defaultdict >>> list1 = [['X1',2],['X2',4],['Y1',2],['Y2',4]] >>> d = defaultdict(dict) >>> for (c,i), n in list1: ... d[c][i] = n ... >>> d

问题 This is my data: File1 Name School Age Weight Jack St John 15 Jack St Mary 14 Jack St Michael 12 Mary St John 16 Mary St Mary 12 Mary St Michael 15 Raw data Name School Weight Jack St John 80 Jack St Mary 75 Jack St Michael 95 Mary St John 75 Mary St Mary 65 Mary St Michael 80 I want to fetch Weight values referring Raw data. I tried with MATCH and INDEX, however I kept on getting #VALUE! . Any ideas what to use to fetch these Weight values? 回答1: The conventional solution is to use a helper

问题 This is my data: File1 Name School Age Weight Jack St John 15 Jack St Mary 14 Jack St Michael 12 Mary St John 16 Mary St Mary 12 Mary St Michael 15 Raw data Name School Weight Jack St John 80 Jack St Mary 75 Jack St Michael 95 Mary St John 75 Mary St Mary 65 Mary St Michael 80 I want to fetch Weight values referring Raw data. I tried with MATCH and INDEX, however I kept on getting #VALUE! . Any ideas what to use to fetch these Weight values? 回答1: The conventional solution is to use a helper