CRUD API

As mentioned in the introduction section, running ent on the schemas, will generate the following assets:

• Client and Tx objects used for interacting with the graph.
• CRUD builders for each schema type.
• Entity object (Go struct) for each of the schema type.
• Package containing constants and predicates used for interacting with the builders.
• A migrate package for SQL dialects. See Migration for more info.

Create A New Client

SQLite

package main

import (
    "context"
    "log"

    "entdemo/ent"

    _ "github.com/mattn/go-sqlite3"
)

func main() {
    client, err := ent.Open("sqlite3", "file:ent?mode=memory&cache=shared&_fk=1")
    if err != nil {
        log.Fatalf("failed opening connection to sqlite: %v", err)
    }
    defer client.Close()
    // Run the auto migration tool.
    if err := client.Schema.Create(context.Background()); err != nil {
        log.Fatalf("failed creating schema resources: %v", err)
    }
}

PostgreSQL

package main

import (
    "context"
    "log"

    "entdemo/ent"

    _ "github.com/lib/pq"
)

func main() {
    client, err := ent.Open("postgres","host=<host> port=<port> user=<user> dbname=<database> password=<pass>")
    if err != nil {
        log.Fatalf("failed opening connection to postgres: %v", err)
    }
    defer client.Close()
    // Run the auto migration tool.
    if err := client.Schema.Create(context.Background()); err != nil {
        log.Fatalf("failed creating schema resources: %v", err)
    }
}

MySQL

package main

import (
    "context"
    "log"

    "entdemo/ent"

    _ "github.com/go-sql-driver/mysql"
)

func main() {
    client, err := ent.Open("mysql", "<user>:<pass>@tcp(<host>:<port>)/<database>?parseTime=True")
    if err != nil {
        log.Fatalf("failed opening connection to mysql: %v", err)
    }
    defer client.Close()
    // Run the auto migration tool.
    if err := client.Schema.Create(context.Background()); err != nil {
        log.Fatalf("failed creating schema resources: %v", err)
    }
}

Gremlin (AWS Neptune)

package main

import (
    "log"

    "entdemo/ent"
)

func main() {
    client, err := ent.Open("gremlin", "http://localhost:8182")
    if err != nil {
        log.Fatal(err)
    }
}

Create An Entity

Save a user.

a8m, err := client.User.    // UserClient.
    Create().               // User create builder.
    SetName("a8m").         // Set field value.
    SetNillableAge(age).    // Avoid nil checks.