How to generate unique values while initializing values

Question

I am initializing values in my pl/sql program and want to use a sequence to set my unique ids but it errors out. Below is what I use.
ie. table_id := table_seq.nextval;
How can I use my sequence to initialize values or is this possible?

Answer 1

The method suggested by user605919 will work. However, you don't need to initialize a variable like this. It is better and more performant to do it like the third example below:
SQL> create table mytable
  2  ( id number(6)
  3  , description varchar2(30)
  4  )
  5  /
Tabel is aangemaakt.
SQL> create sequence table_seq start with 1 increment by 1
  2  /
Reeks is aangemaakt.
SQL> declare
  2    table_id mytable.id%type := table_seq.nextval;
  3  begin
  4    insert into mytable
  5    ( id
  6    , description
  7    )
  8    values
  9    ( table_id
10    , 'Some description'
11    );
12  end;
13  /
  table_id mytable.id%type := table_seq.nextval;
FOUT in regel 2:
.ORA-06550: line 2, column 41:
PLS-00357: Table,View Or Sequence reference 'TABLE_SEQ.NEXTVAL' not allowed in this context
ORA-06550: line 2, column 12:
PL/SQL: Item ignored
ORA-06550: line 9, column 5:
PLS-00320: the declaration of the type of this expression is incomplete or malformed
ORA-06550: line 9, column 5:
PL/SQL: ORA-00904: "TABLE_ID": invalid identifier
ORA-06550: line 4, column 3:
PL/SQL: SQL Statement ignored
SQL> declare
  2    table_id mytable.id%type;
  3  begin
  4    select table_seq.nextval
  5      into table_id
  6      from dual
  7    ;
  8    insert into mytable
  9    ( id
10    , description
11    )
12    values
13    ( table_id
14    , 'Some description'
15    );
16  end;
17  /
PL/SQL-procedure is geslaagd.
SQL> begin
  2    insert into mytable
  3    ( id
  4    , description
  5    )
  6    values
  7    ( table_seq.nextval
  8    , 'Some description'
  9    );
10  end;
11  /
PL/SQL-procedure is geslaagd.And if you need the id value for some code after the insert, you use the RETURNING clause.
Regards,
Rob.