prevent duplicate rows

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hello dears

I have one database with two tables (record_table,attachments)

record_table

ID, subject,note

attachments

ID, ID_record_table,path

relationship between tables:

the record_table.id = attachment.ID_record_table

but when one row in record_table has 2 attachment .and when I use select statement i will see 2 results for the same row in record_table. so how can I prevent duplicate rows.

SQL

(SELECT * FROM record_table LEFT JOIN attachment on record_table.id = attachment.ID_record_table)

Posted 15-Jan-16 8:36am

Somar Rateeb

Updated 15-Jan-16 8:44am

Maciej Los

v2

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Maciej Los 15-Jan-16 14:52pm

Hhmmmmm.... What's an issue?

2 solutions

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Wendelius · Accepted Answer · 2016-01-15T08:53:00

Solution 1

Since you're joining the two tables you will get as many rows in the result set how many rows satisfy the join condition. In other words, if one record has two attachments, two rows are returned.-

The rows aren't duplicates. If you have a look at the columns coming from attachment table you see that the contain the values from both rows.

Have a look at Visual Representation of SQL Joins[^]

Posted 15-Jan-16 8:53am

Wendelius

Updated 15-Jan-16 8:54am

v2

Comments

Maciej Los 15-Jan-16 15:00pm

Mika, i think you misunderstod the prblem. In my opinion OP wants to check if attachment extists in attachments table, but... i'm not sure.

Wendelius 15-Jan-16 15:05pm

Thanks for the comment. That is one possibility, but I'm afraid that there is a misunderstanding what a join actually does. This is why I suggest going through the join types. Hopefully the OP responds if I've misunderstood the situation :)

Maciej Los 15-Jan-16 15:07pm

Yeah, it's true. This might be a problem too.

Maciej Los 17-Jan-16 5:00am

You were right, so have a 5!

Member 11449483 · Accepted Answer · 2016-01-16T00:08:00

Solution 2

try this,

sql - join two tables and show all records - Stack Overflow[^]

Posted 16-Jan-16 0:08am

Member 11449483