Re: BUG #1698: Different behavior in UNIQUE and DISTINCT
От | Mauro Delfino |
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Тема | Re: BUG #1698: Different behavior in UNIQUE and DISTINCT |
Дата | |
Msg-id | 8d465be205061306124d947056@mail.gmail.com обсуждение исходный текст |
Ответ на | Re: BUG #1698: Different behavior in UNIQUE and DISTINCT (Bruno Wolff III <bruno@wolff.to>) |
Ответы |
Re: BUG #1698: Different behavior in UNIQUE and DISTINCT
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Список | pgsql-bugs |
Yes I'm sure. I was created right before filling it. Thanks, Mauro 2005/6/3, Bruno Wolff III <bruno@wolff.to>:=20 >=20 > On Thu, Jun 02, 2005 at 20:22:07 +0100, > Mauro Delfino <maurodelfino@gmail.com> wrote: > > > > I have the these two tables: > > CREATE TABLE table_one > > ( field1 VARCHAR(255) ); > > > > CREATE TABLE table_two > > ( field1 VARCHAR(255) UNIQUE ); > > > > table_one has 500k records. I certify that all strings are distinct with > > this query: > > SELECT DISTINCT field1 FROM table_one; > > The query results 500k rows. > > > > But if I try to insert the records of table_one into table_two with the > > following command: > > INSERT INTO table_two (field1) (SELECT field1 FROM table_one); > > This error occurs: > > ERROR: duplicate key violates unique constraint "table_two_field1_key" > > > > What happened? DISTINC and UNIQUE have different algorithms to determine > > when two strings are equal? >=20 > Are you sure table_two is empty when you do this? >=20 --=20 Mauro Delfino=20 maurodelfino@gmail.com=20 (48) 9933-6933 (MCDBA/MCSE/MCP+I/IBM Lotus CLS)=20 Microsoft SQL Server Official Beta Tester
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