xql: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On CentOS possible default full paths are:

/usr/bin/xql - from package: xbsql

You may install the required package with command yum install {package}

Error in other languages:
xql: bevel nie gevind nie
xql: comandă negăsită
xql: comando não encontrado
xql: commande introuvable
xql: command not found
xql: käsku ei ole
xql: không tìm thấy lệnh
xql: komanda nerasta
xql: Kommando nicht gefunden.
xql: kommandot finns inte
xql: komut yok
xql: nie znaleziono polecenia
xql: níor aimsíodh an t-ordú
xql: no se encontró la orden
xql: no s'ha trobat l'ordre
xql: opdracht niet gevonden
xql: parancs nem található
xql: perintah tidak ditemukan
xql: príkaz nenájdený
xql: příkaz nenalezen
xql: команда не найдена
xql: командата не е открита
xql: 命令找不到
xql: コマンドが見つかりません