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| Database - Interview Questions and Answers for 'Unique constraint' - 2 question(s) found - Order By Newest | |||||
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| Ans. This error can result either on an insert, update or delete when any change in data results in duplicate record or subset of it having unique constraint on record or its subset. For example - If we have a unique constraint on a combination of columns and then trying to insert duplicate column values. | |||||
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 Discuss Correct / Improve  database Unique Constraint error Unique Constraint violated | |||||
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| Ans. Unique constraint ensures that a columns or combination or columns are always unique in a table and hence doesn't allow null or duplicates to be entered for the column or combination of columns. | |||||
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| Discuss Correct / Improve unique constraint | |||||
| Related Questions | |||||
 What's the benefit for specifying constraints like Not Null , Primary Key explicitly instead of specifying it against the column ? | |||||
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| Which constraint cannot be specified as an explicit constraint and should be specified with the column only ? | |||||
| How to know the constraints on a Table in Oracle ? | |||||
| When do we generally get this database error - integrity constraint violated - parent key not found ? | |||||
| When do we generally get the database error - Unique Constraint Violated ? | |||||
| Write an SQL Statement to add a foreign key constraint in oracle ? | |||||
| What do you make out of this error org.hibernate.exception.ConstraintViolationException: could not insert: [<Entity>] Caused by: java.sql.SQLIntegrityConstraintViolationException: ORA-00001: unique constraint (<Constraint Name>) violated and how would you go about debugging it ? | |||||
| What is ConstraintViolationException in Hibernate ? | |||||
| What are the different database constraint types ? | |||||
