PHP和MYSQL - 如何检查两行或更多行是否具有相同的字段值

Question

So here's the problem I can't work around today.

I want to grab some details from a database. I'm not sure how to explain this. But here goes.

Database Example:

TITLE | DESCRIPTION | IDENTIFIER

1 | Description | abc
2 | Description | abc
3 | Description | def

I want to select the first row with the identifier "abc" and then I want to skip the next row which has the same field "abc".

I'm trying to use this in a SELECT mysql_query in PHP

Answer 1

To get the complete row you can do

select * from your_table
where title in 
(
  select min(title)
  from your_table
  group by identifier
)

Answer 2

This?

SELECT DISTINCT(identifier), title, description FROM tablename

It will also return the row with 'def' in this case.

Answer 3

It appears that the integer field is called 'title'. This should grab the lowest title # but remove the duplicates as you requested.

select min(title) as firstTitle, description, identifier
  from table_name
  where identifier in (select distinct identifier from table_name)
  group by description, identifier.

Answer 4

select min(TITLE) as TITLE, DESCRIPTION , IDENTIFIER 
From your_table
Group by DESCRIPTION , IDENTIFIER 

Answer 5

select id, description, identifier 
from table group by identifier order by id asc;