sql: Scan error on column index 2, name "col3": unsupported Scan, storing driver.Value type []string into type *sql.RawBytes

[exfly]

GORM Playground Link

go-gorm/playground#1

package main

import (
	"fmt"

	"gorm.io/driver/clickhouse"
	"gorm.io/gorm"
)

type User struct {
	Uniqid uint8  `gorm:"column:col1"`
	Name   string `gorm:"column:col2"`
}

func (User) TableName() string {
	return "user"
}

func main() {
	dsn := "clickhouse://user:passwd@localhost:9010/test?dial_timeout=10s&read_timeout=20s"
	rawDB, err := gorm.Open(clickhouse.Open(dsn), &gorm.Config{})
	if err != nil {
		panic("failed to connect database")
	}

	rawDB.Exec("DROP TABLE IF EXISTS user")
	err = rawDB.Exec(`
	CREATE TABLE user (
		  col1 UInt8
		, col2 String
		, col3 Array(String)
	) Engine = Memory
`).Error
	if err != nil {
		panic(err)
	}

	u := User{
		Uniqid: 1,
		Name:   "gorm",
	}

	err = rawDB.Table("user").Create(&u).Error
	if err != nil {
		panic(err)
	}

	var raw []User
	err = rawDB.Table("user").Select("col1,col2").Find(&raw).Error
	if err != nil {
		panic(err) // works !!!
	}

	err = rawDB.Table("user").Find(&raw).Error
	if err != nil {
		panic(err) // panic: sql: Scan error on column index 2, name "col3": unsupported Scan, storing driver.Value type []string into type *sql.RawBytes
	}

	fmt.Println("Ok")
}

Description

If a non-base type exists in the table, Find will ret err:

`panic: sql: Scan error on column index 2, name "col3": unsupported Scan, storing driver.Value type []string into type *sql.RawBytes`

[exfly]

temp workaround：

rawDB, err := gorm.Open(clickhouse.Open(dsn), &gorm.Config{
    QueryFields: true,
})

In addition, if you want to use the array, you can consider the following custom types:

type StringArray []string

func (a *StringArray) Scan(value interface{}) error {
	*a, _ = value.([]string)
	return nil
}

func (a StringArray) Value() (driver.Value, error) {
	val, err := json.Marshal([]string(a))
	if err != nil {
		return nil, err
	}
	return val, nil
}

type User struct {
	Uniqid  uint8  `gorm:"column:col1"`
	Name   string `gorm:"column:col2"`
        Tags     StringArray
}

[zhaojia123]

你的可以用？dsn := "clickhouse://username:pwd#@host:9000/database?dial_timeout=10s&read_timeout=20s"
rawDB, err := gorm.Open(clickhouse.Open(dsn), &gorm.Config{})
if err != nil {
fmt.Print("failed to connect database")
}
fmt.Print(rawDB)为啥 就这两行 都链接不上啊，官方的就行 他娘嘞 处死后 都错误 failed to initialize database,