How to find record in table by hex value in bytea column?

[stasvo]

I have a problem of find records in tablbe by hex string in bytea column when use argument.
For example I have hash 83d0c8c41e14f33c94cdb5a9b875c418e82ebd82 which stored in bytea column.
If I use query without arguments, in this way, then its works without problems:
select bytea_column from table where bytea_column = '\x83d0c8c41e14f33c94cdb5a9b875c418e82ebd82';
But is I use it as strign argument it doesnt works in my case.
select bytea_column from table where bytea_column = $1;
I tried pass '\x83d0c8c41e14f33c94cdb5a9b875c418e82ebd82' to argument as string.
I tried pass '83d0c8c41e14f33c94cdb5a9b875c418e82ebd82' to argument as string.
I tried this way which also didnt work:

decoded, err := hex.DecodeString("83d0c8c41e14f33c94cdb5a9b875c418e82ebd82")
$1 = decoded

What a right way to use this value as argument for bytea?

[jackc]

You should be able to use a []byte as an bytea parameter. hex.DecodeString should have done what you want.

package main

import (
	"context"
	"encoding/hex"
	"log"
	"os"

	"github.com/jackc/pgx/v5"
)

func main() {
	ctx := context.Background()

	conn, err := pgx.Connect(ctx, os.Getenv("DATABASE_URL"))
	if err != nil {
		log.Fatal(err)
	}
	defer conn.Close(ctx)

	b, err := hex.DecodeString("01020304")
	if err != nil {
		log.Fatal(err)
	}

	var isEqual bool
	err = conn.QueryRow(ctx, `select '\x01020304'::bytea = $1::bytea`, b).Scan(&isEqual)
	if err != nil {
		log.Fatal(err)
	}

	log.Println("isEqual:", isEqual)
}

jack@glados ~/dev/pgx_issues/pgx-1649 ±master⚡ » go run .
2023/06/18 06:56:25 isEqual: true

[stasvo]

Thank you.