jamesfrj jamesfrj - 2 months ago 7
SQL Question

Conditional unique constraint with multiple fields in oracle db

I have this table:

XPTO_TABLE (id, obj_x, date_x, type_x, status_x)


I wanna create a unique constraint that applies to the fields
(obj_x, date_x, type_x)
only when
status_x <> 5
.

I have tried to create this one but Oracle says:

line 1: ORA-00907: missing right parenthesis




CREATE UNIQUE INDEX UN_OBJ_DT_TYPE_STATUS
ON XPTO_TABLE(
(CASE
WHEN STATUS_X <> 5
THEN
(OBJ_X,
TO_CHAR (DATE_X, 'dd/MM/yyyy'),
TYPE_X)
ELSE
NULL
END));


What's the correct syntax ?

Answer

@jamesfrj: it looks like you are trying to ensure that your table should contain only one record for which status <>5.

You can try creating a unique functional index by concatenating the columns, as given below

      create table XPTO_TABLE (id number, 
                            obj_x varchar2(20),
                            date_x date,
                            type_x varchar2(20),
                            status_x varchar2(20)                              
                           );

      create unique index xpto_table_idx1 on XPTO_TABLE(case when status_x <>'5'  THEN              obj_x||date_x||type_x||STATUS_x ELSE null END);

Hope it helps

Vishad

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