使用游标。
create procedure myproc2(colname varchar(128)) returning varchar(128)
define str1 varchar(128);
define querysql lvarchar(2048);
let querysql = 'select ' || colname || ' from t1';
prepare stmt_id from querysql;
declare querycur cursor for stmt_id;
open querycur;
fetch querycur into str1;
close querycur;
return str1;
end procedure;