sqlite

问题 I'm trying to get the questions from the SqLite for the quiz. I am getting unknowing error. I'm not understanding how to solve that error and how I got that. I'm getting stuck in this since many days. go through many docs but it is not helping to solve the error. This is my DBHelper: public class DBHelper extends SQLiteOpenHelper { private String packageName; private static final String db_name = "quiz_db.db"; private String db_path; private static int db_version = 1; Context con; public

问题 What is an alternative in SQLite as STR_TO_DATE() funciton in MySQL? 回答1: I know that this post is somewhat outdated but I am posting anyways for those who might have a similar issue as I did. I was getting a date from an open api as "2013-01-01T01:00:00+0000" and storing it as a string in sqlite. Problem arose when I needed some way of querying the records based on date range. Since I wasn't able to use STR_TO_DATE() I found that I could use the sqlite function strftime(). Below is an

问题 I'm trying to create a multi-column unique index using a shadow property. I know I can solve this problem with just adding a property, but I would like to see if this is possible in a way to keep my model clean. To create a multi-column index you have the following option in Fluent API: modelBuilder.Entity<AlbumTrack>().HasIndex(t => new { t.TrackNumber, t.AlbumId).IsUnique(); But I don't want to clutter my model with an extra AlbumId property and thus would like to use a shadow property, for

问题 I'm new to Django and try to see a SQLite3 file. I'm looking for a way to open and view a database content with visual studio code like Pycharm can do (see picture) Does an extension could do that? Is it possible to achieve this in VSC? 回答1: I published an extension to query and explore sqlite3 databases vscode-sqlite 回答2: Obviously, there is not yet a corresponding extension for vscode. Me, if necessary, I use "SQLite-Database-Browser". Very simple and sufficient for my purposes. If you want

问题 I'm new to Django and try to see a SQLite3 file. I'm looking for a way to open and view a database content with visual studio code like Pycharm can do (see picture) Does an extension could do that? Is it possible to achieve this in VSC? 回答1: I published an extension to query and explore sqlite3 databases vscode-sqlite 回答2: Obviously, there is not yet a corresponding extension for vscode. Me, if necessary, I use "SQLite-Database-Browser". Very simple and sufficient for my purposes. If you want

问题 As suggested in comments from Key: value store in Python for possibly 100 GB of data, without client/server and in other questions, SQLite could totally be used as a persistent key:value store. How would you define a class (or just wrapper functions) such that using a key:value store with SQLite would be as simple as: kv = Keyvaluestore('/test.db') kv['hello'] = 'hi' # set print(kv['hello']) # get print('blah' in kv) # answer: False because there's no key 'blah' in the store kv.close() ? 回答1:

问题 As suggested in comments from Key: value store in Python for possibly 100 GB of data, without client/server and in other questions, SQLite could totally be used as a persistent key:value store. How would you define a class (or just wrapper functions) such that using a key:value store with SQLite would be as simple as: kv = Keyvaluestore('/test.db') kv['hello'] = 'hi' # set print(kv['hello']) # get print('blah' in kv) # answer: False because there's no key 'blah' in the store kv.close() ? 回答1:

问题 I want the value of one JComboBox to change depending upon the value of another JComboBox . in one JComboBox , I am showing designation of doctors, which I retrieve from the database. Depending on that designation I want to show the name of doctors in another JComboBox . all the information is stored in doctor table. 回答1: Add an ActionListener to the first combo box. In the listener you need to reset the ComboBoxModel of the second combo box based on the selected item. Something like: import

问题 What is the syntax to UPDATE a BLOB field in an existing SQLite record, using Python? I create a 13x13 array of floats and want to Update a specific record (i.e. using a WHERE clause) in my table with that array. What is the proper UPDATE syntax? The array has the following form: [ 4.65640926e+00 5.59250259e+00 5.28963852e+00 1.60680866e+00 -3.39492680e-01 -4.76834650e-01 -4.76834650e-01 -2.29132240e-01 1.49733067e+00 1.51563072e+00 1.49733067e+00 9.53471420e-01 -1.40306473e+00] [ 5.28963852e

问题 I am completing the 'Python for everybody' course on coursera . I am stuck on the 'Mailing List Data - Part I' I have the following code below: import sys import sqlite3 import time import ssl from urllib import request from urllib.parse import urljoin from urllib.parse import urlparse import re from datetime import datetime, timedelta # Not all systems have this so conditionally define parser try: import dateutil.parser as parser except: pass def parsemaildate(md): # See if we have dateutil