遇到 golang 运行时错误，当尝试使用 db.QueryRow

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我有controller.go：

package controller
import (
    "github.com/fishkaoff/todolist/pkg/postgresql"
    "github.com/gin-gonic/gin"
    "net/http"
    "context"
)

type task struct {
    title string 
    description string
 }


func gettasks(c *gin.context) {
    var response *task
    err := db.conn.queryrow(context.background(), "select * from tasks").scan(&response.title, 
    &response.description)
    if err != nil {
        c.json(http.statusinternalservererror, gin.h{"error":"error"})
    }

    c.json(200, gin.h{
        "page":"gettasks",
        "tasks": response,
    })
}

当我发送请求时，它会返回我

```runtime error: invalid memory address or nil pointer dereference
c:/program files/go/src/runtime/panic.go:260 (0xb7bab5)
        panicmem: panic(memoryerror)
c:/program files/go/src/runtime/signal_windows.go:255 (0xb7ba85)
        sigpanic: panicmem()
d:/workspace/golangwww/pkg/mod/github.com/jackc/pgx/[email protected]/conn.go:551 (0x1015db1)
        (*conn).query: simpleprotocol := c.config.prefersimpleprotocol
d:/workspace/golangwww/pkg/mod/github.com/jackc/pgx/[email protected]/conn.go:663 (0x101b9dc)
        (*conn).queryrow: rows, _ := c.query(ctx, sql, args...)
d:/workspace/golangwww/todolist/internal/controller/controller.go:17 (0x101b9ab)
        gettasks: err := db.conn.queryrow(context.background(), "select * from tasks").scan(&response.title, &response.description)
d:/workspace/golangwww/pkg/mod/github.com/gin-gonic/[email protected]/context.go:173 (0xeb99c1)
        (*context).next: c.handlers[c.index](c)
d:/workspace/golangwww/pkg/mod/github.com/gin-gonic/[email protected]/recovery.go:101 (0xeb99ac)
        customrecoverywithwriter.func1: c.next()
d:/workspace/golangwww/pkg/mod/github.com/gin-gonic/[email protected]/context.go:173 (0xeb8ac6)
        (*context).next: c.handlers[c.index](c)
d:/workspace/golangwww/pkg/mod/github.com/gin-gonic/[email protected]/logger.go:240 (0xeb8aa9)
        loggerwithconfig.func1: c.next()
d:/workspace/golangwww/pkg/mod/github.com/gin-gonic/[email protected]/context.go:173 (0xeb7bd0)
        (*context).next: c.handlers[c.index](c)
d:/workspace/golangwww/pkg/mod/github.com/gin-gonic/[email protected]/gin.go:616 (0xeb7838)
        (*engine).handlehttprequest: c.next()
d:/workspace/golangwww/pkg/mod/github.com/gin-gonic/[email protected]/gin.go:572 (0xeb74fc)
        (*engine).servehttp: engine.handlehttprequest(c)
c:/program files/go/src/net/http/server.go:2947 (0xd70feb)
        serverhandler.servehttp: handler.servehttp(rw, req)
c:/program files/go/src/net/http/server.go:1991 (0xd6d6c6)
        (*conn).serve: serverhandler{c.server}.servehttp(w, w.req)
c:/program files/go/src/runtime/asm_amd64.s:1594 (0xb96320)
        goexit: byte    $0x90   // nop```

db.conn 是从 db.go 导入的：

package db


    import (
        "os"
        "fmt"
        "context"


        "github.com/jackc/pgx/v4/"
        "github.com/fishkaoff/todoList/internal/config"
    )

    var Conn *pgx.Conn

    func InitDatabase(config config.Config) {
        Conn, err := pgx.Connect(context.Background(), config.DBUrl)
        if err != nil {
            fmt.Fprintf(os.Stderr, "Unable to connect to database: %v\n", err)
            os.Exit(1)
        }
        defer Conn.Close()
    }

initdatabase 正在 main.go 中调用

在数据库中创建表和列

我正在使用 pgx v4

p.s：抱歉我的英语不好，我不是母语人士 ⁣⁣⁣⁣⁣⁣⁣⁣⁣⁣⁣⁣⁣⁣⁣⁣____________________________________________________________ ⁣⁣⁣⁣⁣⁣⁣⁣⁣⁣⁣⁣⁣⁣⁣⁣⁣⁣⁣

正确答案

var response *task

您已分配内存来存储 *task，而不是 task。

然后当你

.scan(&response.title,     &response.description)

尝试获取 response.title 和 response.description 的地址。这些字段没有地址，因为 response 是一个指针，但不指向有效的任务。

尝试：

var response Task

现在您实际上已经为 title 和 description 字段分配了空间，因此有地方可以存储这些值。

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