Enable and Disable all constraints in Oracle

Check the constraint present in the table.

col type format a10
 col cons_name format a24
 COL TABLE_NAME FOR A25
 select  decode(constraint_type,
         'C', 'Check',
         'O', 'R/O View',
         'P', 'Primary',
         'R', 'Foreign',
         'U', 'Unique',
         'V', 'Check view') type
 ,   constraint_name cons_name
 , TABLE_NAME
 from  dba_constraints
 where  table_name='EMP'
 order by 1;

Enable and Disable the Constraint

--Disable
ALTER TABLE table_name DISABLE CONSTRAINT constraint_name;

--Enable
ALTER TABLE table_name ENABLE CONSTRAINT constraint_name

Disable all the constraints with CASCADE in Schema

select 'alter table '||owner||'.'||table_name|| ' disable constraint '||constraint_name||';' from all_constraints where delete_rule = 'CASCADE' and owner = 'HR';

Enable all the constraints in the Schema

select 'alter table '||owner||'.'||table_name|| ' enable constraint '||constraint_name||';' from all_constraints where owner = 'HR';