sql.DB 集成

下面的示例将说明如何将自定义 sql.DB对象传递给 ent.Client.

配置 sql.DB

方法一：

package main

import (
    "time"

    "<your_project>/ent"
    "github.com/facebookincubator/ent/dialect/sql"
)

func Open() (*ent.Client, error) {
    drv, err := sql.Open("mysql", "<mysql-dsn>")
    if err != nil {
        return nil, err
    }
    // 获取驱动的底层 sql.DB 对象。
    db := drv.DB()
    db.SetMaxIdleConns(10)
    db.SetMaxOpenConns(100)
    db.SetConnMaxLifetime(time.Hour)
    return ent.NewClient(ent.Driver(drv)), nil
}

方法二：

package main

import (
    "database/sql"
    "time"

    "<your_project>/ent"
    entsql "github.com/facebookincubator/ent/dialect/sql"
)

func Open() (*ent.Client, error) {
    db, err := sql.Open("mysql", "<mysql-dsn>")
    if err != nil {
        return nil, err
    }
    db.SetMaxIdleConns(10)
    db.SetMaxOpenConns(100)
    db.SetConnMaxLifetime(time.Hour)
    // Create an ent.Driver from `db`.
    // 从 `db` 创建一个 ent.Driver.
    drv := entsql.OpenDB("mysql", db)
    return ent.NewClient(ent.Driver(drv)), nil
}

在 MySQL 中使用 Opencensus

译者注：OpenCensus 是 Google 开源的一个用来收集和追踪应用程序指标的第三方库。目前 Opencensus 已经与 OpenTracing 合并

package main

import (
    "context"
    "database/sql"
    "database/sql/driver"

    "<project>/ent"

    "contrib.go.opencensus.io/integrations/ocsql"
    "github.com/go-sql-driver/mysql"
    entsql "github.com/facebookincubator/ent/dialect/sql"
)

type connector struct {
    dsn string
}

func (c connector) Connect(context.Context) (driver.Conn, error) {
    return c.Driver().Open(c.dsn)
}

func (connector) Driver() driver.Driver {
    return ocsql.Wrap(
        mysql.MySQLDriver{},
        ocsql.WithAllTraceOptions(),
        ocsql.WithRowsClose(false),
        ocsql.WithRowsNext(false),
        ocsql.WithDisableErrSkip(true),
    )
}

// 打开新的连接并启动统计记录器。
func Open(dsn string) *ent.Client {
    db := sql.OpenDB(connector{dsn})
    // 从 `db` 创建一个 ent.Driver.
    drv := entsql.OpenDB("mysql", db)
    return ent.NewClient(ent.Driver(drv))
}