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https://github.com/SwifQL/SwifQL
π A Swift DSL for type-safe, extensible, and transformable SQL queries.
https://github.com/SwifQL/SwifQL
dsl mysql postgresql sql swift
Last synced: 4 months ago
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π A Swift DSL for type-safe, extensible, and transformable SQL queries.
- Host: GitHub
- URL: https://github.com/SwifQL/SwifQL
- Owner: SwifQL
- License: mit
- Created: 2018-12-12T00:18:20.000Z (over 5 years ago)
- Default Branch: master
- Last Pushed: 2023-09-11T02:12:55.000Z (10 months ago)
- Last Synced: 2024-01-12T07:44:54.102Z (6 months ago)
- Topics: dsl, mysql, postgresql, sql, swift
- Language: Swift
- Homepage:
- Size: 476 KB
- Stars: 289
- Watchers: 10
- Forks: 21
- Open Issues: 6
-
Metadata Files:
- Readme: README.md
- License: LICENSE
Lists
- awesome-server-side-swift - SwifQL - Easily build flexible and type-safe SQL with pure Swift (Packages / Database)
README
[](http://mihaelisaev.com)
This lib can be used either stand alone, or with frameworks like Vapor, Kitura, Perfect and others
We recommend to use it with our [Bridges](https://github.com/SwifQL/Bridges) lib which is built on top of SwifQL and support all its flexibility
It supports PostgreSQL and MySQL. And it's not so hard to add other dialects π just check [SwifQL/Dialect](https://github.com/SwifQL/SwifQL/tree/master/Sources/SwifQL/Dialect) folder
Please feel free to ask any questions in issues, and also you could find me in the [Discord app](https://discordapp.com) as `@iMike#3049` or even better just join **#swifql** channel on [Vapor's Discord server](https://discord.gg/vapor) π
> NOTE:
>
> If you haven't found some functions available out-of-the-box
> then please check files like `SwifQLable+Select` and others in `Sources/SwifQL` folder
> to ensure how easy it is to extend SwifQL to support anything you need π
>
> And feel free to send pull requests with your awesome new extensions β€οΈ
### Support SwifQL development by giving a βοΈ
## Installation
### With Vapor 4 + [Bridges](https://github.com/SwifQL/Bridges) + PostgreSQL
```swift
.package(url: "https://github.com/vapor/vapor.git", from:"4.0.0-rc"),
.package(url: "https://github.com/SwifQL/VaporBridges.git", from:"1.0.0-rc"),
.package(url: "https://github.com/SwifQL/PostgresBridge.git", from:"1.0.0-rc"),
.target(name: "App", dependencies: [
.product(name: "Vapor", package: "vapor"),
.product(name: "VaporBridges", package: "VaporBridges"),
.product(name: "PostgresBridge", package: "PostgresBridge")
]),
```
### With Vapor 4 + [Bridges](https://github.com/SwifQL/Bridges) + MySQL
```swift
.package(url: "https://github.com/vapor/vapor.git", from:"4.0.0-rc"),
.package(url: "https://github.com/SwifQL/VaporBridges.git", from:"1.0.0-rc"),
.package(url: "https://github.com/SwifQL/MySQLBridge.git", from:"1.0.0-rc"),
.target(name: "App", dependencies: [
.product(name: "Vapor", package: "vapor"),
.product(name: "VaporBridges", package: "VaporBridges"),
.product(name: "MySQLBridge", package: "MySQLBridge")
]),
```
### Pure
```swift
.package(url: "https://github.com/MihaelIsaev/SwifQL.git", from:"2.0.0-beta"),
.target(name: "App", dependencies: [
.product(name: "SwifQL", package: "SwifQL"),
]),
```
### Pure on NIO2
```swift
.package(url: "https://github.com/MihaelIsaev/SwifQL.git", from:"2.0.0-beta"),
.package(url: "https://github.com/MihaelIsaev/SwifQLNIO.git", from:"2.0.0"),
.target(name: "App", dependencies: [
.product(name: "SwifQL", package: "SwifQL"),
.product(name: "SwifQLNIO", package: "SwifQLNIO"),
]),
```
#### Pure on NIO1 (deprecated)
```swift
.package(url: "https://github.com/MihaelIsaev/SwifQL.git", from:"1.0.0"),
.package(url: "https://github.com/MihaelIsaev/SwifQLNIO.git", from:"1.0.0"),
.target(name: "App", dependencies: ["SwifQL", "SwifQLNIO"]),
```
#### With Vapor 3 + Fluent (deprecated)
```swift
.package(url: "https://github.com/MihaelIsaev/SwifQL.git", from:"1.0.0"),
.package(url: "https://github.com/MihaelIsaev/SwifQLVapor.git", from:"1.0.0"),
.target(name: "App", dependencies: ["Vapor", "SwifQL", "SwifQLVapor"]),
```
## Philosophy
This lib gives an ability to build absolutely any SQL query from simplest to monster complex.
Example of simple query
```sql
SELECT * FROM "User" WHERE "email" = '[email protected]'
```
build it with pure SwifQL this way
```swift
SwifQL.select(User.table.*).from(User.table).where(\User.email == "[email protected]")
```
or with SwifQL + [Bridges](https://github.com/SwifQL/Bridges)
```swift
SwifQL.select(User.table.*).from(User.table).where(\User.$email == "[email protected]")
// or shorter
User.select.where(\User.$email == "[email protected]")
```
## Usage
### Preparation
> π‘ TIP: It is simpler and more powerful with [Bridges](https://github.com/SwifQL/Bridges)
Of course you have to import the lib
```swift
import SwifQL
```
#### For v1 Your table models should be conformed to `Tableable` protocol
```swift
extension MyTable: Tableable {}
```
#### For v2 Your table models should be conformed to `Table` protocol
```swift
extension MyTable: Table {}
```
### How to build query
> Instead of writing `Model.self` you should write `Model.table`, cause without Vapor you should conform your models to `Table`, and with Vapor its `Model`s are already conforms to `Table`.
```swift
let query = SwifQL.select(\User.email, \User.name, \User.role)
.from(User.table)
.orderBy(.asc(\User.name))
.limit(10)
```
or with SwifQL + [Bridges](https://github.com/SwifQL/Bridges)
```swift
let query = SwifQL.select(\User.$email, \User.$name, \User.$role)
.from(User.table)
.orderBy(.asc(\User.$name))
.limit(10)
// or shorter
User.select(\.$email, \.$name, \.$role).orderBy(.asc(\User.$name)).limit(10)
```
### How to print raw query
There are two options
##### 1. Get just plain query
```swift
let rawSQLString = query.prepare(.psql).plain
```
or when using SwifQLSelectBuilder() - see below
```swift
let rawSQLBuilderString = query.build().prepare(.psql).plain
```
##### 2. Get object splitted into: formatted raw SQL string with $ symbols, and separated array with values
```swift
let splittedQuery = query.prepare(.psql).splitted
let formattedSQLQuery = splittedQuery.query // formatted raw SQL string with $ symbols instead of values
let values = splittedQuery.values // an array of [Encodable] values
```
Then just put it into your database driver somehow π or use [Bridges](https://github.com/SwifQL/Bridges)
### How to execute query?
SwifQL is only about building queries. For execution you have to use your favourite database driver.
Below you can see an example for SwifQL + Vapor4 + [Bridges](https://github.com/SwifQL/Bridges) + PostgreSQL
> π‘ You can get connection on both `Application` and `Request` objects.
Example for `Application` object e.g. for `configure.swift` file
```swift
// Called before your application initializes.
public func configure(_ app: Application) throws {
app.postgres.connection(to: .myDb1) { conn in
SwifQL.select(User.table.*).from(User.table).execute(on: conn).all(decoding: User.self).flatMap { rows in
print("yaaay it works and returned \(rows.count) rows!")
}
}.whenComplete {
switch $0 {
case .success: print("query was successful")
case .failure(let error): print("query failed: \(error)")
}
}
}
```
Example for `Request` object
```swift
func routes(_ app: Application) throws {
app.get("users") { req -> EventLoopFuture<[User]> in
req.postgres.connection(to: .myDb1) { conn in
SwifQL.select(User.table.*).from(User.table).execute(on: conn).all(decoding: User.self)
}
}
}
```
> π‘ In examples above we use `.all(decoding: User.self)` for decoding results, but we also can use `.first(decoding: User.self).unwrap(or: Abort(.notFound))` to get only first row and unwrap it since it may be nil.
## Insert Into
### Single record
SQL example
```sql
INSERT INTO "User" ("email", "name") VALUES ('[email protected]', 'John Doe'), ('[email protected]', 'Samuel Jackson')
```
SwifQL representation
```swift
SwifQL.insertInto(User.table, fields: \User.email, \User.name).values("[email protected]", "John Doe")
```
or with SwifQL + [Bridges](https://github.com/SwifQL/Bridges)
```swift
User(email: "[email protected]", name: "John Doe").insert(on: conn)
```
### Batch
SQL example
```sql
INSERT INTO "User" ("email", "name") VALUES ('[email protected]', 'John Doe'), ('[email protected]', 'Samuel Jackson')
```
SwifQL representation
```swift
SwifQL.insertInto(User.table, fields: \User.email, \User.name).values(array: ["[email protected]", "John Doe"], ["[email protected]", "Samuel Jackson"])
```
or with SwifQL + [Bridges](https://github.com/SwifQL/Bridges)
```swift
let user1 = User(email: "[email protected]", name: "John")
let user2 = User(email: "[email protected]", name: "Amily")
let user3 = User(email: "[email protected]", name: "Trololo")
[user1, user2, user3].batchInsert(on: conn)
```
## Update
### General Update
SQL example
```sql
UPDATE "User" SET "name" = 'Mike'
```
SwifQL representation
```swift
SwifQL.update(User.table).set[items: User.$name == "Mike"]
```
### In Schema Update
SQL example
```sql
UPDATE "VIP"."User" SET "name" = 'Mike'
```
SwifQL representation
```swift
let vip = User.inSchema("VIP")
SwifQL.update(vip.table).set[items: vip.$name == "Mike"]
```
## Builders
For now there are only one implemented builder
### Select builder
`SwifQLSelectBuilder` - by using it you could easily build a select query but in multiple lines without carying about ordering.
```swift
let builder = SwifQLSelectBuilder()
builder.where(\User.id == 1)
builder.from(User.table)
builder.limit(1)
builder.select(User.table.*)
let query = builder.build()
return query.execute(on: req, as: .psql)
.first(decoding: User.self)
.unwrap(or: Abort(.notFound, reason: "User not found"))
```
So it will build query like: `SELECT "User".* FROM "User" WHERE "User"."id" = 1 LIMIT 1`.
As you can see you shouldn't worry about parts ordering, it will sort them the right way before building.
### More builders
Feel free to make your own builders and send pull request with it here!
Also more conveniences are available in [Bridges](https://github.com/SwifQL/Bridges) lib which is created on top of SwifQL and support all its flexibility
## More query examples
*Let's use `SwifQLSelectBuilder` for some next examples below, cause it's really convenient especially for complex queries.*
1. Let's imagine that you want to query count of users.
```swift
/// Just query
let query = SwifQL.select(Fn.count(\User.id) => "count").from(User.table)
/// Execution and decoding for Vapor
struct CountResult: Codable {
let count: Int64
}
query.execute(on: req, as: .psql)
.first(decoding: CountResult.self)
.unwrap(or: Abort(.notFound)) // returns Future
```
Here you can see two interesting things: `Fn.count()` and `=> "count"`
`Fn` is a collection of function builders, so just call `Fn.` and take a look at the functions list on autocompletion.
`=>` uses for two things: 1) to write alias through `as` 2) to cast values to some other types
`// TBD: Expand list of examples`
## Aliasing
Use `=>` operator for that, e.g.:
If you want to write `SELECT "User"."email" as eml` then do it like this `SwifQL.select(\User.email => "eml")`
Or if to speak about table name aliasing:
If you want to reach `"User" as u` then do it like this `User.as("u")`
And then keypaths will work like
```swift
let u = User.as("u")
let emailKeypath = u.email
```
## Type casting
Use `=>` operator for that, e.g.:
If you want to write `SELECT "User"."email"::text` then do it like this `SwifQL.select(\User.email => .text)`
## Predicates
| Infix operator | SQL equivalent |
| ------- | -------------- |
| > | > |
| >= | >= |
| < | < |
| <= | <= |
| == | = |
| == nil | IS NULL |
| != | != |
| != nil | IS NOT NULL |
| && | AND |
And also
`||` is for `OR`
`||>` is for `@>`
`<||` is for `<@`
> Please feel free to add more predicates in `Predicates.swift` π
## Operators
Please feel free to take a look at `Fn.Operator` enum in `Functions.swift`
## Functions
Please feel free to take a look at the list of function in `Functions.swift`
## Postgres JSON Object
You could build JSON objects by using `PostgresJsonObject`
SQL example
```sql
jsonb_build_object('id', "User"."id", 'email', "User"."email")
```
SwifQL representation
```swift
PgJsonObject().field(key: "id", value: \User.id).field(key: "email", value: \User.email)
```
## Postgres Array
You could build PostgreSQL arrays by using `PostgresArray`
SQL example
```sql
$$[]$$
ARRAY[]
ARRAY[1,2,3]
$$[]$$::uuid[]
ARRAY[]::text[]
```
SwifQL representation
```swift
PgArray(emptyMode: .dollar)
PgArray()
PgArray(1, 2, 3)
PgArray(emptyMode: .dollar) => .uuidArray
PgArray() => .textArray
```
Postgress range query examples
```swift
// var ingredients: [IngredientsEnum]
SwifQL.select(FoodMenu.table.*).WHERE( \FoodMenu.$ingredients ||> [.tomato] )
// var ingredients: [String]
SwifQL.select(FoodMenu.table.*).WHERE( \FoodMenu.$ingredients ||> PgArray(["tomato"]) )
// var vendors: [UUID]
SwifQL.select(FoodMenu.table.*).WHERE( \FoodMenu.$vendors ||> PgArray([vendorUuid]) )
```
## Nesting array of objects inside of query result
Consider such response object you want to achieve:
```swift
struct Book {
let title: String
let authors: [Author]
}
struct Author {
let name: String
}
```
you have to build it with use of subquery to dump Authors in JSON array and then attach them to result query. This will allow you to get all `Books` with their respective `Authors`
This example uses Pivot table `BookAuthor` to join `Books` with their `Authors`
```swift
let authors = SwifQL.select(Fn.coalesce(Fn.array_agg(Fn.to_jsonb(Author.table)), PgArray() => .jsonbArray))
let query = SwifQLSelectBuilder()
query.select(Book.table.*)
query.from(Book.table)
query.join(.left, BookAuthor.table, on: \Book.$id == \BookAuthor.$bookID)
query.join(.left, Author.table, on: \Author.$id == \BookAuthor.$authorID)
// then query.group(...) as required in your case
```
## FILTER
SQL example
```sql
COUNT("User"."id") FILTER (WHERE \User.isAdmin = TRUE) as "admins"
```
SwifQL representation
```swift
Fn.count(\User.id).filter(where: \User.isAdmin == true) => "admins"
```
## CASE ... WHEN ... THEN ... END
SQL example
```sql
CASE
WHEN "User"."email" IS NULL
THEN NULL
ELSE "User"."email"
END
```
SwifQL representation
```swift
Case.when(\User.email == nil).then(nil).else(\User.email).end
// or as many cases as needed
Case.when(...).then(...).when(...).then(...).when(...).then(...).else(...).end
```
## Brackets
Yes, we really often use round brackets in our queries, e.g. in where clauses or in subqueries.
SwifQL provides you with `|` prefix and postfix operators which is representates `(` and `)`.
So it's easy to wrap some part of query into brackets, e.g.:
SQL example
```sql
"User.role" = 'admin' OR ("User.role" = 'user' AND "User"."age" >= 21)
```
SwifQL representation
```swift
let where = \User.role == .admin || |\User.role == .user && \User.age >= 21|
```
## Keypaths
| SQL | SwiftQL | SwiftQL + Bridges |
| ------- | -------------- | -------------- |
| `"User"` | `User.table` | `the same` |
| `"User" as u` | `User.as("u")` you could declare it as `let u = User.as("u")` | `the same` |
| `"User".*` | `User.table.*` | `the same` |
| `u.*` | `u.*` | `the same` |
| `"User"."email"` | `\User.email` | `\User.$email` |
| `u."email"` | `u.email` | `u.$email` |
| `"User"."jsonObject"->"jsonField"` | `\User.jsonObject.jsonField` | `only through full path for now` |
| `"User"."jsonObject"->"jsonField"` | `Path.Table("User").column("jsonObject", "jsonField")` | `the same` |
## Tests
For now tests coverage is maybe around 70%. If you have timΠ΅ and interest please feel free to send pull requests with more tests.
You could find tests in `Tests` folder
### How it works under the hood
`SwifQL` object needed just to start writing query, but it's just an empty object that conforms to `SwifQLable`.
You can build your query with everything which conforms to `SwifQLable`, because `SwifQLable` is that very piece which will be used for concatenation to build a query.
> If you take a look at the lib's files you may realize that the most of files are just extensions to `SwifQLable`.
All available operators like `select`, `from`, `where`, and `orderBy` realized just as a function in `SwifQLable` extension and these functions always returns `SwifQLable` as a result. That's why you can write a query by calling `SwifQL.select().from().where().orderBy()` one by one. That's awesome cause it feels like writing a raw SQL, but it also gives you an ordering limitation, so if you write `SwifQL.select().where().from()` then you'll get wrong query as a result. But this limitation is resolved by using special builders, like `SwifQLSelectBuilder` (read about it later below).
So let's take a look how lib builds a simple `SELECT "User".* FROM "User" WHERE "User"."email" = '[email protected]'` query
First of all we should split query into the parts. Almost every word and punctuation here is a `SwifQLable` piece.
- `SELECT` is `Fn.Operator.select`
- ` ` is `Fn.Operator.space`
- `"User"` is `User.table`
- `.*` is `postfix operator .*`
- ` ` is `Fn.Operator.space`
- `FROM` is `Fn.Operator.from`
- `"User"` is `User.table`
- ` ` is `Fn.Operator.space`
- `WHERE` is `Fn.Operator.where`
- ` ` is `Fn.Operator.space`
- `"User"."email"` is `\User.email` keypath
- ` ` is `Fn.Operator.space`
- `==` is `infix operator ==`
- ` ` is `Fn.Operator.space`
- `'[email protected]'` is `SwifQLPartUnsafeValue` (it means that this value should be passed as $1 to the database)
That's crazy, but awesome, right? π But it's under the hood, so no worries! π I just wanted to explain, that if you need something more than already provided then you'll be able to add needed operators/functions easily just by writing little extensions.
> And also there is no overhead, it works pretty fast, but I'd love to hear if you know how to make it faster.
This way gives you almost absolute flexibility in building queries. More than that as lib support `SQLDialect`'s it will build this query different way for PostgreSQL and MySQL, e.g.:
- PostgreSQL: `SELECT "User".* FROM "User" WHERE "User"."email" = '[email protected]'`
- MySQL: `SELECT User.* FROM User WHERE User.email = '[email protected]'`
## Contributing
Please feel free to contribute!