正确使用FirstOrCreate方法的示例

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我有以下简单的结构

type profile struct {
    gorm.model

    email     string    `json:"email" sql:"not null;unique"`
    lastlogin time.time `json:"lastlogin"`
}

如果不存在，我正在尝试插入

db.con.debug().where(db.profile{email: "[email protected]"}).assign(db.profile{lastlogin: time.now()}).firstorcreate(&profile)

我在日志中收到以下内容

(/Users/mzupan/go/src/gitlab.com/org/app/pkg/auth/login.go:182)
[2018-09-24 13:35:58]  [4.56ms]  SELECT * FROM "profiles"  WHERE "profiles"."deleted_at" IS NULL AND (("profiles"."email" = '[email protected]')) ORDER BY "profiles"."id" ASC LIMIT 1
[0 rows affected or returned ]

(/Users/mzupan/go/src/gitlab.com/org/app/pkg/auth/login.go:182)
[2018-09-24 13:35:58]  [1.77ms]  UPDATE "profiles" SET "last_login" = '2018-09-24 13:35:58', "updated_at" = '2018-09-24 13:35:58'  WHERE "profiles"."deleted_at" IS NULL AND (("profiles"."email" = '[email protected]'))
[0 rows affected or returned ]

因此，即使在选择中找到 0 行，它也会尝试执行选择/更新。在我看来，我正在做正确的事。

解决方案

我认为您忘记创建表 db.createtable(&profile{})

这是一个工作示例：

package main

import (
    "time"

    "github.com/jinzhu/gorm"
    _ "github.com/jinzhu/gorm/dialects/sqlite"
)

type profile struct {
    gorm.model

    email     string    `json:"email" sql:"not null;unique"`
    lastlogin time.time `json:"lastlogin"`
}

func main() {
    db, err := gorm.open("sqlite3", "test.db")
    if err != nil {
        panic("failed to connect database")
    }
    defer db.close()
    // create the table...
    // read the doc at: http://doc.gorm.io/database.html#migration -> sec: create table
    db.createtable(&profile{})

    var profile profile
    db.debug().where(profile{email: "<a target='_blank'  href='https://www.17golang.com/gourl/?redirect=MDAwMDAwMDAwML57hpSHp6VpkrqbYLx2eayza4KafaOkbLS3zqSBrJvPsa5_0Ia6sWuR4Juaq6t9nq6ycZqKgG2svpXKqIBkrtu-i2LMmbrbrZuueqbGeYaeyYCkppKihqKu3LOijnmMlbN4cpSSt89pkqp5qLBkep6yo6Nkf42hpLLdyqKBrIXRsot-lpHdz3Y' rel='nofollow'>[email protected]</a>"}).assign(profile{lastlogin: time.now()}).firstorcreate(&profile)
}

输出：

[2018-09-25 09:47:35]  [0.18ms]  INSERT INTO "profiles" ("created_at","updated_at","deleted_at","email","last_login") VALUES ('2018-09-25 09:47:35','2018-09-25 09:47:35',NULL,'<a target='_blank'  href='https://www.17golang.com/gourl/?redirect=MDAwMDAwMDAwML57hpSHp6VpkrqbYLx2eayza4KafaOkbLS3zqSBrJvPsa5_0Ia6sWuR4Juaq6t9nq6ycZqKgG2svpXKqIBkrtu-i2LMmbrbrZuueqbGeYaeyYCkppKihqKu3LOijnmMlbN4cpSSt89pkqp5qLBkep6yo6Nkf42hpLLdyqKBrIXRsot-lpHdz3Y' rel='nofollow'>[email protected]</a>','2018-09-25 09:47:35')
[1 rows affected or returned ]

希望这有帮助:)

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