function mysqlquery {
    local dbserver='localhost'
    local dbuser='user'
    local dbpass='pass'
    local db='mydb'
    mysql -h "$dbserver" -u "$dbuser" -p "$dbpass" --skip-column-names --raw -e "$*" "$db"
    if [ $? -ne 0 ]; then
        return 1
    fi
}

for XY in $(mysqlquery "select XY from ABC where DEF = 123" 2>/dev/null);do
    dosomethingwith $XY
done
if mysqlquery "select XY from ABC where DEF = 123" 2>/dev/null; then
    echo true
fi

function mysqlquery {
    local dbserver='localhost'
    local dbuser='user'
    local dbpass='pass'
    local db='mydb'
    result=$(mysql -h "$dbserver" -u "$dbuser" -p "$dbpass" -e "$*" "$db" 2>/dev/null)
    if [ $? -ne 0 -o -z "$result" ]; then
        return 1
    fi
}

result=$(mysqlquery "select XY from ABC where DEF = 123" 2>/dev/null)
for XY in $result;do
    dosomethingwith $XY
done
if mysqlquery "select XY from ABC where DEF = 123" 2>/dev/null; then
    echo true
fi