1985wasagoodyear/SwiftySQLSample

A simple app that demonstrates the usage of SQLite within Swift.

SwiftySQLSample

A simple app that demonstrates the usage of SQLite within Swift.

Table of Contents

1. Installation
2. SQLite Considerations
3. Implementation in Swift
4. Notable Classes
5. References

1. Installation

1. Install pods with pod install
2. Build in Xcode 11.0 or newer, with Swift 5.

Dependencies

1. fmdb

A Cocoa / Objective-C wrapper around SQLite

2. SwiftLint

A tool to enforce Swift style and conventions.

2. SQLite Considerations

• SQLite is not thread-safe, thus you must treat all connections within one thread.
• Each database connection must always be closed when completed.
• SQLite is a relational database.
• libsqlite3.tbd is a library included on all iOS/macOS devices, thus it does not increase the binary size of your application
• As an older technology, the main interface is C.

3. Implementation in Swift

To use SQLite in Swift, we must be using C-code in Swift.

This gives us three options.

• 1. Import SQLite3 and use it directly in Swift, working with the C-style naming convention.
• 2. Use Objective-C as an intermediary for C-level SQLite, which we can then interface with, using Swift.
• 3. Use an existing framework that does 2. because it is a solved problem.

We will be using approach 3, with fmdb.

fmdb also addresses some of the other issues with SQLite databases (none of which are addressed here).

4. Notable Classes

The primary class we will be interacting with is SQLiteManager.

Of notability, the following CRUD functions are implemented:

Create Table

• created automatically when an instance of SQLiteManager is instantiated, if the table does not already exist

Create Entry

• SQLiteManager+Create.swift
• can press the + button at the top-right to call addItemButtonAction in DatesListController
• sets the current date and sets a random hexidecimal value for the name
• saves the entry within SQLite

Read Entries

• SQLiteManager+Read.swift
• on app start, all entries are loaded into the table in DatesListController
• each create/update/delete also reloads all entries, for the sake of demonstration

Update Entry

• SQLiteManager+Update.swift
• tapping on any entry on the table assigns a new hexidecimal value
• SQLite value is updated, then all entries are refreshed from the backing store

Delete Entry

• SQLiteManager+Delete.swift
• swipe-left action on any entry allows for easy deletion
• implemented in respective UITableViewDelegate method trailingSwipeActionsConfigurationForRowAt or editActionsForRowAt, depending on OS version

5. References

GeeksforGeeks SQL References

AppCoda FMDB tutorial