SwiftKnex

A Mysql Native Client and Query Builder that works on Mac and Linux.
This library is powerded by Prorsum

SwiftKnex is aimed to use at production services at my company

Features

• Pure Swift Implementation(doesn’t depend on libmysqlclient)
• Expressive querying
• Supporting Database Migration and Rollback
• Supported Mysql 5.7 JSON Data Type
• Async I/O

TODO

• BlobType
• GeoType
• Investigate Performance
• Async I/O Mode
• Documentation

Contributing

All developers should feel welcome and encouraged to contribute to SwiftKnex.

To contribute a feature or idea to SwiftKnex please submit an issue! If you find bugs, of course you can create the PR(s) directory.

Query Builder Reference

Initializing the Library

let config = KnexConfig(
    host: "localhost",
    user: "user",
    database: "my_database",
    isShowSQLLog: true
)

let con = try KnexConnection(config: config)
let knex = con.knex()

Query Builder

Select

where equal

let results = try knex.table("users").where("id" == 1).fetch()
print(results)

where between and limit and offset

You can chain the conditional clauses like SQL and it’s amazing expressive.

let results = try knex
                  .table("users")
                  .where(between("id", 1, 1000))
                  .limit(10)
                  .offset(10)
                  .fetch()

print(result)

join

let results = try knex
                  .table("users")
                  .join("payments")
                  .on("users.id" == "payment.user_id")
                  .where("users.id" == 1)
                  .limit(10)
                  .offset(10)
                  .fetch()

print(results)

count

let results = try knex
                  .select(count("id").as("count"))
                  .table("users")
                  .fetch()

print(results)

where based on priority

let results = try knex
                    .table("users")
                    .where(("country" == "Japan" && "age" > 20) || "country" == "USA")

print(results)

Sub Query

fetch all rows from the results that taken by subquery.

let results = try knex
                    .table(
                        Table(
                            QueryBuilder()
                              .table("users")
                              .where("country" == "USA")
                            )
                        ).as("t1")
                    )
                    .where("t1.id" == 1)

print(results)

Use ids taken by subquery as argument of in clause

let results = try knex
                    .table("users")
                    .where(SwiftKnex.in("id",
                        QueryBuilder()
                          .select(col("id"))
                          .table("t1")
                          .where("country" == "USA")
                    )).fetch()

print(results)

Operators, Conditions and Clauses

Operators

SwiftKnex can evaluate comparison formula as function. If you input "id" == 1 in where clause, it is evaluated as function(Not BOOL) and tnrasform to SQL Comparison Literal.

SwiftKnex	Mysql
where(“id” == 1)	where id = 1
where(“id” > 1)	where id > 1
where(“id” >= 1)	where id >= 1
where(“id” < 1)	where id < 1
where(“id” <= 1)	where id <= 1
where(“id” != 1)	where id != 1

Conditions

SwiftKnex provides conditions as function. Here are list of conditions available now.

• where(_ filter: ConditionFilter)
  • like: knex().where(like("name", "%a%"))
  • in: knex().where(in("id", [1, 2, 3]))
  • notIn: knex().where(notIn("id", [1, 2, 3]))
  • between: knex().where(between("date", "2017-01-01", "2017-01-31"))
  • notBetween: knex().where(notBetween("date", "2017-01-01", "2017-01-31"))
  • isNull: knex().where(isNull("deleted_at"))
  • isNotNull: knex().where(isNotNull("deleted_at"))
  • raw: knex().where(raw("id = ?", [1]))
• or(_ filter: ConditionFilter)
  • knex().where(in("id", [1, 2, 3])).or(in("id", [4, 5, 6]))

Clauses

Of cource it supports other clauses. You can use them with knex()‘s method chain.

• join(_ table: String): knex().table("a").join("b")
• leftJoin(_ table: String): knex().table("a").leftJoin("b")
• rightJoin(_ table: String): knex().table("a").rightJoin("b")
• innerJoin(_ with table: String): knex().table("a").innerJoin("b")
• on(_ filter: ConditionFilter): knex().table("a").join("b").on("a.id" == "b.a_id")
• limit(_ limit: Int): knex().limit(10)
• offset(_ offset: Int): knex().limit(10).offset(100)
• order(by: String, sort: OrderSort = .asc): knex().order(by: "created_at", .desc)
• group(by name: String): knex().group(by: "company")
• having(_ cond: ConditionFilter): knex().group(by: "company").having(in("name", ["Google", "Apple"]))

TypeSafe Querying with Entity protocol

Define Your Entity with confirming Entity protocol and fetch rows as your specified type.

struct User: Entity, Serializable {
    let id: Int
    let name: String
    let email: String
    let age: Int
    let country: String?

    init(row: Row) throws {
        self.id = row["id"] as! Int
        self.name = row["name"] as! String
        self.email = row["email"] as! String
        self.age = row["age"] as! Int
        self.country = row["country"] as? String
    }

    func serialize() throws -> [String: Any] {
        return [
            "name": name,
            "email": email,
            "age": age,
            "country": country
        ]
    }
}

// fetch rows as User(s)
let users: [User] = try! con.knex()
                            .table("users")
                            .where("country" == "Japan")
                            .fetch()

print(users.first)

// Insert User(should confirm Serializable)
let result = try! con.knex().insert(into: "users", values: user)

print(result?.insertId)

Insert

let result = try knex().insert(into: "users", values: ["id": 1, "name": "bar"])

print(result.affectedRows)

Update

let result = try knex().table("users").where("id" == 1).update(sets: ["name": "foobar"])

print(result.affectedRows)

Delete

let result = try knex().table("users").where("id" == 1).delete()

print(result.affectedRows)

Transaction

do {
    try con.knex().transaction { trx in // BEGIN TRANSCTION
        try con.knex().table("users").where("id" == 1).update(sets: ["name": "foo"], trx: trx)
        try con.knex().table("users").where("id" == 2).update(sets: ["name": "bar"], trx: trx)
        try con.knex().table("users").where("id" == 3).update(sets: ["name": "foobar"], trx: trx)
    }
    // COMMIT
} catch {
    // ROLLBACK
}

DDL

Create

let create = Create(table: "users", fields: [
    Schema.integer("id").asPrimaryKey().asAutoIncrement(),
    Schema.string("name"),
    Schema.string("email").asUnique(),
    Schema.datetime("last_logined_at").asIndex()
])
.hasTimeStamps() // add created_at and updated_at

try knex().execRaw(sql: create.toDDL())

Schema.Field Reference

Schema Types Comparison

SwiftKnex	Mysql Type
Schema.string	VARCHAR
Schema.integer	INT
Schema.bigInteger	BIGIMT
Schema.dateTime	DATETIME
Schema.text	TEXT
Schema.mediumText	MEDIUMTEXT
Schema.float	FLOAT
Schema.double	DOUBLE
Schema.boolean	TINYINT(1)
Schema.json	JSON

Functions for adding field attributes

• default(as value: Any)
• after(for name: String)
• asPrimaryKey()
• asAutoIncrement()
• asNotNullable()
• asUnsigned()
• charset(_ char: Charset)
• asUnique()
• asIndex()

Drop

let drop = Drop(table: "users")
try knex().execRaw(sql: drop.toDDL())

Raw

You can perform raw sql with SwiftKnex

try knex().execRaw(sql: "SELECT * from users where id = ?", params: [1])

Migration

SwiftKnex supports database migration and rollback features.

Flows

1. Install SwiftKnex into your project.

Package.swift

import PackageDescription

let package = Package(
    name: "MyApp",
    dependencies: [
        .Package(url: "https://github.com/noppoMan/SwiftKnex.git", majorVersion: 0, minor: 1)
    ]
)

run swift build

$ swift build

and then, SwiftKnexMigration executable binary was created in the .build/debug directory.

2. Create Migration file

the next step is creating migration class file into your Sources/Migration directory with ./build/debug/Migration create {ResourceName}

here is an example for creating CreateUser migration file

.build/debug/SwiftKnexMigration create CreateUser

#
# Created /YourProject/Sources/Migration/20170116015823_CreateUser.swift
#

3. Edit Your Migration File

After create migration class file, edit it like following.

The created migration class has following methods.

up

Performed on migrate:latest

down

Performed on migrate:rollback

import SwiftKnex
import Foundation

class Migration_20170116015823_CreateUser: Migratable {

    var name: String {
        return "\(Mirror(reflecting: self).subjectType)"
    }

    func up(_ migrator: Migrator) throws {
       let create = Create(
           table: "users",
           fields: [
               Schema.integer("id").asPrimaryKey().asAutoIncrement(),
               Schema.string("name").asIndex().asNotNullable(),
               Schema.string("email").asUnique().asNotNullable()
           ])
           .hasTimestamps()
           .index(columns: ["name", "email"], unique: true)

       try migrator.run(create)
    }

    func down(_ migrator: Migrator) throws {
        try migrator.run(Drop(table: "users"))
    }
}

4. Create main.swift in the {$PROJ}/Sources/Migration

Create main.swift in the {$PROJ}/Sources/Migration directory that is created by Migrate create at previous section.
And copy/paste the following code into your {$PROJ}/Sources/Migration/main.swift and then, replace the class names in the knexMigrations array to correct names, and change the database configuration depending on your environment.

You need to add the new class name(s) to the knexMigrations at every migration resource created.

main.swif example

import SwiftKnex

let knexMigrations: [Migratable] = [
    Migration_20170116015823_CreateUser()
]

let config = KnexConfig(
   host: "localhost",
   user: "root",
   database: "swift_knex_test"
)

try Migrator.run(config: config, arguments: CommandLine.arguments, knexMigrations: knexMigrations)

after editing main.swift, run swift build

swift build

5. Perform Migration and Rollback

After that, you only need to run the migration

Current supporting commands are

• migrate:latest: Perform to migrate recent unmigrated files.
• migrate:rollback: Rollback the migrations recent performed.(The rollback unit is grouped by batch number)

Try to perform Migration

.build/debug/Migration migrate:latest

Try to perform Rollback

.build/debug/Migration migrate:rollback

Seed

TODO

Working with Prorsum

Go Style async query performing and syncronization with Prorsum

import Prorsum

let chan = Channel<ResultSet>.make()

go {
    let rows = try! knex().table("users").where("id" == 1).fetch()
    try chan.send(rows!)
}

go {
    let rows = try! knex().table("users").where("id" == 2).fetch()
    try chan.send(rows!)
}

print(try! chan.receive())
print(try! chan.receive())

Mysql Library

The base Connection and Querying library that used in SwiftKnex.

TODO

License

Prorsum is released under the MIT license. See LICENSE for details.