create table test as ( select '--' name from dual where 1=0 )
select cast ('--' as varchar2(2) ) name from dual where 1=0
create table test as ( select cast('--' as varchar(2)) name from dual where 1=0 )
tst> create table t1(name varchar2(3)) as select '--' name from dual; create table t1(name varchar2(3)) as select '--' name from dual * ERROR at line 1: ORA-01773: may not specify column datatypes in this CREATE TABLE
SQL> create table t1 as 2 select '--' a 3 ,rpad('-',2,'-') b 4 ,'--'||to_char(null) c 5 ,'--'||null d 6 from dual; Таблица создана. SQL> desc t1 Имя Пусто? Тип ----------------------------------------- -------- ------------ A CHAR(2) B VARCHAR2(2) C VARCHAR2(2) D VARCHAR2(2)
substr('--', 1)
decode(1,1,'--')