首先让我说我是 Golang 的新手，并致力于使用 Golang 重构现有的基于 Python 的 API，因此数据库和底层模式已经存在并填充了数据。

我有一个使用 Gin 和 Gorm 的非常基本的 API 设置。在 GET API 调用期间，它能够连接到 MySQL 5.7 后端，但我的查询都不会返回任何内容。我已尝试使用数据库中的已知序列号进行各种查询，并在我在此应用程序外部查询时返回这些序列号。

ma​​in.go

package main

import (
    "github.com/gin-gonic/gin"
    _ "github.com/go-sql-driver/mysql"
    "github.com/jinzhu/gorm"
    "time"
    "log"
    "fmt"
)

var db *gorm.DB

func InitDB() *gorm.DB{
    var err error
    db, err := gorm.Open("mysql", "api:MyPassword@tcp(10.37.1.1:3306)/opt_db1")
    db.SingularTable(true)

    err = db.DB().Ping()

    if err != nil {
        log.Panic(err)
        fmt.Print(err.Error())
    } else {
        fmt.Printf("Successfully connected to MySQL")
    }

    return db
}

type TestResult struct {
    ID                    int  `db:"id" json:"id"`
    DateAdded             time.Time `db:"date_added" json:"date_added"`
    Serial                string  `db:"serial" json:"serial"`
    SequenceId            int `db:"sequence_id" json:"sequence_id"`
    LastCompletedStage    int `db:"last_completed_stage" json:"last_completed_stage"`
    LastCompletedSequence int `db:"last_completed_sequence" json:"last_completed_sequence"`
    Workorder             string  `db:"workorder" json:"workorder"`
    Product               string `db:"product" json:"product"`
    IsComplete            string `db:"is_complete" json:"is_complete"`
    IsScrapped            string `db:"is_scrapped" json:"is_scrapped"`
    ValueStream           string `db:"value_stream" json:"value_stream"`
    PromiseDate           string `db:"promise_date" json:"promise_date"`
    FailLock              int `db:"fail_lock" json:"fail_lock"`
    SequenceRev           int `db:"sequence_rev" json:"sequence_rev"`
    DateUpdated           time.Time `db:"date_updated" json:"date_updated"`
    Date                  time.Time `db:"date" json:"date"`
    Time                  time.Time `db:"time" json:"time"`
    Ptyp2                 string `db:"ptyp2" json:"ptyp2"`
    WoQty                 int `db:"wo_qty" json:"wo_qty"`
    IsActive              int `db:"is_active" json:"is_active"`
    IsTimeLock            int `db:"is_time_lock" json:"is_time_lock"`
    TimeLockTimestamp     time.Time `db:"time_lock_timestamp" json:"time_lock_timestamp"`
    ScrapReason           string `db:"scrap_reason" json:"scrap_reason"`
    ScrappedBy            int `db:"scrapped_by" json:"scrapped_by"`
}

func main() {
    router := gin.Default()

    opt := router.Group("opt/v2")
    {
        opt.GET("/last-completed-test/:serial", LastTest)
    }

    // Add API handlers here
    router.Run(":3000")
}

func LastTest(c *gin.Context) {
    // Connection to the database
    db := InitDB()
    defer db.Close()

    var result TestResult

    // get param and query
    //serial := c.Params.ByName("serial")

    db.Table("test_result").Where("serial = ?", "124111-0027").Scan(&result)

    if result.ID != 0 {
         //Display JSON result
        c.JSON(200, result)
    } else {
        // Display JSON error
        c.JSON(404, gin.H{"error": "Record not found", "code": 404})
    }
}

控制台输出:

[GIN-debug] Listening and serving HTTP on :3000 Successfully connected to MySQL[GIN] 2017/02/15 - 09:05:13 |[97;43m 404 [0m|      4.5005ms | 127.0.0.1 |[97;4 4m  [0m GET     /opt/v2/last-completed-test/124111-0027

网络输出:

{"id":2252920,"date_added":"0001-01-01T00:00:00Z","serial":"","sequence_id":0,"last_completed_stage":0,"last_completed_sequence":0,"workorder":"","product":"","is_complete":"","is_scrapped":"","value_stream":"","promise_date":"","fail_lock":0,"sequence_rev":0,"date_updated":"0001-01-01T00:00:00Z","date":"0001-01-01T00:00:00Z","time":"0001-01-01T00:00:00Z","ptyp2":"","wo_qty":0,"is_active":0,"is_time_lock":0,"time_lock_timestamp":"0001-01-01T00:00:00Z","scrap_reason":"","scrapped_by":0}

来自 Workbench 的架构:

在上面的代码中，我什至硬编码了一个我知道有数据但无济于事的序列号。

在尝试查询我的数据库时，我是否遗漏了一些明显的东西？

谢谢!

最佳答案

需要初始化result变量，试试:

 db.Table("test_result").Where("serial = ?", "124111-0027").Scan(&result)

关于Golang API - MySQL 连接但查询为空，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/42253366/