Udacity Android Learning Note: Lesson 4 Part A

Source: Internet
Author: User

Udacity Android Learning Note: Lesson 4 Part A

/titer1/archimedes of dry Goods shop chores
Source: Https://code.csdn.net/titer1
Contact: 13,073,161,968
Disclaimer: This document is licensed under the following protocols: Free reprint-Non-commercial-non-derivative-retention Attribution | Creative Commons by-nc-nd 3.0, reproduced please specify the author and source.
Tips:https://code.csdn.net/titer1/pat_aha/blob/master/markdown/android/

SQL lesson
4a-15课开始,之前主要是基础 activity life cycle


SQL table looks like this.

    • SELECT * from weather where data = Blalla
    • SELECT * FROM Weather ORDER by Max DESC LIMIT 1//have a try

    • More SQL operation

      • Delete rows
      • Update rows
      • Insert Rows
      • Add columns
    • More SQL APIs in Android
      Get a simple use effect like UrlBuilder

    • More about Data stroage
Overview Arch repeatedly
4a18

Intro to weather Contract

See also Solution weather table colums Solutions

INNER JOIN 2 Tables

Rest time

Don asked the new scholar to delve into the key points of foreign key and joins (in Lesson 4a-23)

Our weather contact

Practice.. Code Time Weathercontract.java


Don shows key/foreign key in detail.

Define constants in contract

Locationentry

Chapter II Sqllite Open Helper and Sunshine database repeated the next station map began to move

Weatherdbhelper Code


-Database name

-related statements for the database
-Create TABLE
-Specify foreign keys

Database testing


The result was not passed.
The approximate reason is that only weather.db has been created and no locatin.db has been created

Next to modify

Here's the next one to make up for the rest of the DB,

Create Sunshine Location DB Solution

SQLite Open Helper on Upgrade

Database upgrade.

-Must manually change the database version number?
-Database changes
-Row Changes
-Column Changes
-Overall structural changes

    • When does it happen?
Chapter III ReadWrite from a database3.1 overview

3.2 Plan

3.3 Difficulty Query


3.4 Code Practice repeatedly
第三章节的代码 集中于此

The key is to execute the previous checklist and write the testlocationtable.

The same principle is used to test Weathertable.ok, let go

End

It took me 2 hours to thank Don for his company.
-Data storage Diagram overview
-Activity lifecycle, changes when rotating the screen (pause. Restart?)
-Database Test

Udacity Android Learning Note: Lesson 4 Part A

Related Article

Contact Us

The content source of this page is from Internet, which doesn't represent Alibaba Cloud's opinion; products and services mentioned on that page don't have any relationship with Alibaba Cloud. If the content of the page makes you feel confusing, please write us an email, we will handle the problem within 5 days after receiving your email.

If you find any instances of plagiarism from the community, please send an email to: info-contact@alibabacloud.com and provide relevant evidence. A staff member will contact you within 5 working days.

A Free Trial That Lets You Build Big!

Start building with 50+ products and up to 12 months usage for Elastic Compute Service

  • Sales Support

    1 on 1 presale consultation

  • After-Sales Support

    24/7 Technical Support 6 Free Tickets per Quarter Faster Response

  • Alibaba Cloud offers highly flexible support services tailored to meet your exact needs.