I have question like this:
suppose I create a table:
create table mytable(msg raw(254));
and there is a record in this table which contains the following message like:
616C6D6B000000......
I want to retrieve the first character from table mytable, I use such a sql statement:
select substr(msg,1,4) from mytable
the result only return the first 2 character: 616C
If i use substr(mst,1,8), then i got what i want.
I was confused about 2 points:
1. what does the number '254' mean in its definition? it means 254 bytes or others?
2. why should substr recognize four bits of raw data as a unit(char)?
who can explain this?
thanks in advance!
Scott
insert into mytable('call')
suppose I create a table:
create table mytable(msg raw(254));
and there is a record in this table which contains the following message like:
616C6D6B000000......
I want to retrieve the first character from table mytable, I use such a sql statement:
select substr(msg,1,4) from mytable
the result only return the first 2 character: 616C
If i use substr(mst,1,8), then i got what i want.
I was confused about 2 points:
1. what does the number '254' mean in its definition? it means 254 bytes or others?
2. why should substr recognize four bits of raw data as a unit(char)?
who can explain this?
thanks in advance!
Scott
insert into mytable('call')
