SQL行输出按时间戳分组

Question

I've got the following table structure:

Time_Stamp  Number
9/07/13     234
9/07/13     345
9/07/13     456
10/07/13    765
10/07/13    834
10/07/13    257

And I would like to print it like this:

9/07/13     234 345 456
10/07/13    765 834 257

Any idea how i could go about it?

EDIT:

This is how I'm printing the rows at the moment:

    if(!$result_db_post = $db->query($query)){
          die('There was an error running the query [' . $db->error . ']');
      }

       while($row = $result_db_post->fetch_assoc()){

          echo $row['time_stamp'] ." ". $row['number'];
          echo "<br />";                               
}

Which results in this output:

    9/07/13 234
    9/07/13 345
    9/07/13 456
   10/07/13 765
   10/07/13 834
   10/07/13 257

I've tried both queries and both result in the same output.

select Time_Stamp, group_concat(Number separator ' ') as Numbers
from t
group by Time_Stamp;

And I also tried:

SELECT Time_Stamp, GROUP_CONCAT(Number) From table group by Time_Stamp

Any idea what I'm doing wrong?

Answer 1

You seem to want to put the numbers in the same order as they are in the original data. However, SQL tables are inherently unordered, so there is an issue.

It is unclear whether you want them in one column or three. As one column, you can do it using:

select Time_Stamp, group_concat(Number separator ' ') as Numbers
from t
group by Time_Stamp;

If you want them in three columns, you can do the following:

select Time_Stamp,
       substring_index(group_concat(Number), ',', 1) as Number1,
       substring_index(substring_index(group_concat(Number), ',', 2), -1) as Number2,
       substring_index(substring_index(group_concat(Number), ',', 3), -1) as Number3
from t
group by Time_Stamp;

However, the ordering is indeterminate.

Answer 2

使用GROUP_CONCAT函数 ，请尝试以下查询：

SELECT Time_Stamp, GROUP_CONCAT(Number) From table group by Time_Stamp