sqlite

How can I reference columns by their names in python calling SQLite?

由 大城市里の小女人 提交于 2020-01-22 10:46:07
问题 I have some code which I've been using to query MySQL, and I'm hoping to use it with SQLite. My real hope is that this will not involve making too many changes to the code. Unfortunately, the following code doesn't work with SQLite: cursor.execute(query) rows = cursor.fetchall() data = [] for row in rows data.append(row["column_name"]) This gives the following error: TypeError: tuple indices must be integers Whereas if I change the reference to use a column number, it works fine: data.append

论Sqlite、SpringBoot、oracle、redis集成所需要的干货

由 独自空忆成欢 提交于 2020-01-22 08:37:53
论Sqlite、SpringBoot、oracle、redis集成所需要的干货 话不多多说！直接上菜 创建SpringBoot项目 这一块我们不说了 直接略过 大家基本上都会！！！ (1).pom文件依赖 < dependencies > < dependency > < groupId > org . springframework . boot < / groupId > < artifactId > spring - boot - starter - web < / artifactId > < / dependency > < dependency > < groupId > org . springframework . boot < / groupId > < artifactId > spring - boot - starter - data - redis < / artifactId > < / dependency > < dependency > < groupId > org . mybatis . spring . boot < / groupId > < artifactId > mybatis - spring - boot - starter < / artifactId > < version > 2.0 .0 < / version > < /

Unable to load sqlite database on first run

由 旧街凉风 提交于 2020-01-22 04:05:08
问题 I have created an app when I install and launch it for first time it closes automatically but when I open it after it works fine. If I clear data of the app it also closes for first time. It shows android.database.sqlite.SQLiteCantOpenDatabaseException: unknown error (code 14): Could not open database Can anyone help here is my log 11-22 23:14:56.175 13193-13193/? I/art: Late-enabling -Xcheck:jni 11-22 23:14:56.195 13193-13193/? D/TidaProvider: TidaProvider() 11-22 23:14:56.285 13193-13193

Unable to load sqlite database on first run

由 爷，独闯天下 提交于 2020-01-22 04:05:04
问题 I have created an app when I install and launch it for first time it closes automatically but when I open it after it works fine. If I clear data of the app it also closes for first time. It shows android.database.sqlite.SQLiteCantOpenDatabaseException: unknown error (code 14): Could not open database Can anyone help here is my log 11-22 23:14:56.175 13193-13193/? I/art: Late-enabling -Xcheck:jni 11-22 23:14:56.195 13193-13193/? D/TidaProvider: TidaProvider() 11-22 23:14:56.285 13193-13193

Count specific values of a column in SQL and display in row according unique identifier

由 大兔子大兔子 提交于 2020-01-22 03:36:08
问题 I have to following table named results: Position | Country ------------------- 1 | US 2 | Italy 3 | France 1 | US 2 | France 3 | Italy and I want to create the following Country | 1 | 2 | 3 | --------------------- US | 2 | 0 | 0 | Italy | 0 | 1 | 1 | France | 0 | 1 | 1 | I believe the best way to move forward is using pivot tables, can someone give me advice on how to proceed? 回答1: You can use conditional aggregation: select country, sum(case when position = 1 then 1 else 0 end) as pos_1,

android check duplicate values before inserting data into database

由 拈花ヽ惹草 提交于 2020-01-22 02:55:29
问题 String new_recorded_lastname="a lastname"; ////record to database...... Cursor cursor = db.rawQuery("SELECT lastname FROM people; ",null); if (cursor != null){ while(cursor.moveToNext()){ String recorded_lastname=cursor.getString(cursor.getColumnIndex("lastname")); if(!(recorded_lastname.equals(new_recorded_lastname))){ //add new_recorded_lastname to database break; } } } I want to have a lastname only once in my database. Even though I check with "if(!(recorded_lastname.equals(new_recorded

xamarin.forms: retrieving existing data from .db file

由 故事扮演 提交于 2020-01-22 02:24:46
问题 In Xamarin Forms 4.3, I'm following this "Local Databases" doc: https://docs.microsoft.com/en-us/xamarin/xamarin-forms/data-cloud/data/databases This doc explains how to create and use a new sqlite db, but how do I go about in loading and displaying data in an existing .db file with the end purpose of transferring it into a new local sqlite database? using SQLite; namespace TruckExample.Models { public class Truck { [PrimaryKey, AutoIncrement] public int TruckNo { get; set; } public string

RuntimeError while retriving data from sqlite database in android

由 泪湿孤枕 提交于 2020-01-22 01:11:58
问题 I'm trying to insert and retrieve data from database in eclipse using sqlite, but it shows a RuntimeError . I create a layout with three edit texts and one button to create simple information from but nothing is created. I create java database with the following code: package com.example.databasetest; import android.content.ContentValues; import android.content.Context; import android.database.SQLException; import android.database.sqlite.SQLiteDatabase; import android.database.sqlite

RuntimeError while retriving data from sqlite database in android

由 不想你离开。 提交于 2020-01-22 01:11:36
问题 I'm trying to insert and retrieve data from database in eclipse using sqlite, but it shows a RuntimeError . I create a layout with three edit texts and one button to create simple information from but nothing is created. I create java database with the following code: package com.example.databasetest; import android.content.ContentValues; import android.content.Context; import android.database.SQLException; import android.database.sqlite.SQLiteDatabase; import android.database.sqlite

ON DELETE CASCADE not working in SQLite

由 こ雲淡風輕ζ 提交于 2020-01-22 00:56:04
问题 In SQLite for iOS (3.7.7) I am running these queries: PRAGMA foreign_keys = ON; create table venue(id integer primary key not null, name text not null); create table event(id integer primary key not null, name text not null, venue_id integer references venue(id) on delete cascade); But when I delete a venue, the children events are not deleted. Any ideas? 回答1: I followed what Catcall said and it worked for me: setting foreign_keys by running stmt.execute("PRAGMA foreign_keys = ON"); each time
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