package main

import (
	"database/sql"
	"fmt"

	_ "github.com/go-sql-driver/mysql"
)

func main() {
	b := []byte{0x41, 0xf6, 0xec, 0x9a}
	db, _ := sql.Open("mysql", "root:@tcp(127.0.0.1:4000)/test")
	defer db.Close()
	db.Exec(`DROP TABLE IF EXISTS test`)
	db.Exec(`CREATE TABLE IF NOT EXISTS test (a BINARY(4))`)
	db.Exec(`SET SESSION tidb_general_log = 1`)
	db.Exec(`INSERT INTO test VALUES (?)`, b)
	db.Exec(fmt.Sprintf(`select * from test where a = _binary '%s'`, b))
}

sql="select * from test where a = _binary 'A\ufffd\ufffd\ufffd'"

[2024/11/14 18:42:53.920 -08:00] [INFO] [session.go:3929] [GENERAL_LOG] [conn=1138753544] [session_alias=] [[email protected]] [schemaVersion=55] [txnStartTS=0] [forUpdateTS=0] [isReadConsistency=false] [currentDB=test] [isPessimistic=false] [sessionTxnMode=PESSIMISTIC] [sql="select * from test where a = _binary 'A???'"]