Add unique constraints : Unique « Table « Oracle PL/SQL Tutorial






SQL>
SQL>
SQL> set echo off
SQL> create table emp(
  2           emp_id            integer     primary key using index (create index pk_idx on emp(emp_id) )
  3          ,lastname               varchar2(20)   constraint lastname_create_nn not null
  4          ,firstname              varchar2(15)   constraint firstname_create_nn not null
  5          ,midinit                varchar2(1)
  6          ,street                 varchar2(30)
  7          ,city                   varchar2(20)
  8          ,state                  varchar2(2)
  9          ,zip                    varchar2(5)
 10          ,shortZipCode           varchar2(4)
 11          ,area_code              varchar2(3)
 12          ,phone                  varchar2(8)
 13          ,company_name           varchar2(50)
 14          ,constraint unique_emp_phone unique(phone) using index (create index emp_phone_u_idx on emp(phone))
 15          );

Table created.

SQL>
SQL> select index_name, table_name, column_name from user_ind_columns where table_name = 'emp';

no rows selected

SQL>
SQL> select constraint_name, table_name, column_name from user_cons_columns where table_name = 'emp';

no rows selected

SQL>
SQL> drop table emp             cascade constraints;

Table dropped.








6.12.Unique
6.12.1.Adding a UNIQUE Constraint
6.12.2.Add unique constraint across more than one columns
6.12.3.Add unique constraints for combined columns
6.12.4.Add unique constaint to new added column
6.12.5.Violate an unique constraints
6.12.6.Add unique constraints
6.12.7.ORA-00001: unique constraint (JAVA2S.JOB_UNIQUE_IN_TEAMID) violated