IOS development - Database - Introduction to basic knowledge (01)

One summary

• IOS How to store data in
• SQLite database
• Use Navicat Perform table operations

Two IOS How to store data in

• Plist(NSArray\NSDictionary)： Only data and dictionaries can be stored
• Preference( preferences \NSUserDefaults)： System comes with , Deposit in Preference One in the directory is named after this application package plist file
• NSCoding(NSKeyedArchiver\NSkeyedUnarchiver)： follow NSCoding agreement , Write objects to and parse objects from files
• SQLite3： database , pure C Language , Lightweight
• Core Data： database , be based on SQLite3,OC edition , huge , heavyweight

3、 ... and SQLite database

3.1 SQLite

What is a database

• database （Database） It's organized according to the data structure 、 Warehouse for storing and managing data
• The database can be divided into 2 Types ： Relational database and non relational database

What is? SQLite database

• SQLite Is a lightweight embedded database
• It takes up very low resources , In embedded devices , It may take only a few hundred K That's enough memory
• It's faster than Mysql、PostgreSQL These two famous databases are fast

Common relational databases

• PC End ：Oracle、MySQL、SQL Server、Access、DB2、Sybase
• The embedded \ Mobile client ：SQLite

3.2 How to store data

How does a database store data

The storage structure of the database and excel It's like , By table （table） In units of

The steps of storing data in database

• Create a new table （table）
• Add multiple fields （column, Column , attribute ）
• Add multiple lines of records （row,record, Each line holds the values corresponding to multiple fields ）

Four Use Navicat Perform table operations

4.1 Software inventory

• Navicat

4.2 establish SQLite file

open Navicat, Click on the top left Connection, Choose... From the drop-down list SQLite

Set up Connection Name, choice Type by New SQLite 3, stay Database File Choose Save SQLite file name

After successful creation SQLite The structure is as follows

4.3 Create a table

stay Tables Right click on the or click on the... On the right + Number , Execute create table

Add table fields (Type Yes 4 An option ),id Set to Auto Increment( The primary key increases automatically )

Click the save button , Set table name

4.4 Add data

Select the table to add data , Click on the bottom + Add data

The view after adding data is as follows