Creating a full-fledged database in Swift from scratch is a complex task that usually involves working with database management systems like SQLite, CoreData, or other third-party libraries. SQLite is a popular choice for iOS and macOS app development because it’s a lightweight, embedded database engine.
Here, I’ll provide a basic example of how to work with SQLite in Swift to create a simple database and perform basic operations like creating a table, inserting data, and querying data. Please note that this is just a minimal example, and real-world applications might require more complex database design and management.
Import SQLite Library:
First, you need to import SQLiteSwift or another SQLite library for Swift. You can add SQLite.swift to your project using CocoaPods, Carthage, or Swift Package Manager.
Create a SQLite Database and Table:
In your Swift code, you can create a database and define a table like this:
import SQLite
let db: Connection? = try? Connection(“my_database.db”)
let users = Table(“users”)
let id = Expression(“id”)
let name = Expression(“name”)
let age = Expression(“age”)do {
try db?.run(users.create { table in
table.column(id, primaryKey: true)
table.column(name)
table.column(age)
})
} catch {
print(“Error creating table: (error)”)
}
This code establishes a connection to the SQLite database “my_database.db” and creates a “users” table with three columns: “id,” “name,” and “age.”
- Insert Data: You can insert data into the table like this:
do {
let insert = users.insert(name <- “John”, age <- 30)
let rowID = try db?.run(insert)
print(“Inserted row with ID: (rowID ?? 0)”)
} catch {
print(“Insertion failed: (error)”)
}
Query Data:
Retrieve data from the database using queries:
do {
for user in try db!.prepare(users) {
print(“ID: (user[id]), Name: (user[name]), Age: (user[age])”)
}
} catch {
print(“Query failed: (error)”)
}
This code performs a basic select query and prints the results.
Remember to handle errors and use proper error handling practices in your production code. In a real-world application, you might also want to create models and encapsulate database operations in separate classes or modules for better organization.
Note: Make sure to include the SQLite.swift library in your project and set up the appropriate dependencies as needed. You can also consider using Core Data, Realm, or other third-party libraries for more advanced database operations in Swift.
