Differences between UNIQUE and DISTINCT in select statements
Answers were Sorted based on User's Feedback
Answer / anilkumar kambala
UNIQUE:
UNIQUE CAN TAKE UNIQUE DATA
USING DISTINCT CLAUSE SORTING THE DATA
Is This Answer Correct ? | 4 Yes | 1 No |
Answer / pravin d. survase
UNIQUE is only used in oracle but,
DISTINCT is used in all RDBMS.
UNIQUE is used in SELECT statement and as KEY also.
DISTINCT is only used in SELECT.
DISTINCT KEY concept is not present in SQL/ORACLE.
UNIQUE also supress the duplicates but, UNIQUE KEY will
allow the duplicates.
DISTINCT supress the duplicates.
Is This Answer Correct ? | 4 Yes | 2 No |
Answer / prabha
Distinct:
Its gives only the non duplicate values in a database table.
Unique:
The UNIQUE constraint uniquely identifies each record in a
database table.its similar to primary key.these values
cannot be repeated.
Is This Answer Correct ? | 3 Yes | 1 No |
Answer / carol
unique is a constraint on coloumnsbut distinct is used in DML for query retrieval in select
Is This Answer Correct ? | 2 Yes | 0 No |
Answer / cutepa1
Yeah Manoj, Thatz ok, UNIQUE as a constraint. But I like to
know about the diff while its usage in select statement. For
me it seems very similar to DISTINCT, can anyone give me if
there is any difference, please.
Is This Answer Correct ? | 15 Yes | 15 No |
Answer / howard cheon
DISTINCT AND UNIQUE are same operation.
But, You cannot specify DISTINCT if the select_list
contains LOB columns.
Is This Answer Correct ? | 16 Yes | 16 No |
Answer / hemasundar
Distinct:Its gives only the non duplicate values in a database table.
Unique:The UNIQUE constraint uniquely identifies each record in a database table.its similar to primary key.these values
cannot be repeated.But, nearly both are same...
Is This Answer Correct ? | 0 Yes | 0 No |
Answer / narendrasai
UNIQUE: it is a constraint and it was created at the time of table creation, where as
DISTINCT: it is a word used at the time of selection.
So both are same, but usage of both the words are different
Is This Answer Correct ? | 0 Yes | 0 No |
Answer / vijay mohan reddy
Hi Howard Cheon,
you are currect... but we cant able to use
both DISTINCT and UNIQUE, if the select_list contains LOB,
LONG columns. It may not a difference.
Could anyone plz give some another major difference..
Thanks in Advance
Vijay Reddy.
Is This Answer Correct ? | 9 Yes | 10 No |
Answer / ajeet
there is no diff between distinct and unique in user point
of view. both are same. same functionality. dont bother
about it use whatever you want....
Is This Answer Correct ? | 4 Yes | 5 No |
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