从MySQL查询返回空结果时，在数组上分配零值

Question

Can I assign "0" value on an array that returned no results from a MySQL Query?

If so, can you show me how?

my code goes something like this:

    $grapes_query = mysql_query("SELECT fruitDate, fruitName, COUNT(*) FROM tbl_fruits WHERE fruitName='Grapes' GROUP BY 

    fruitDate");
    while ($grapes = mysql_fetch_assoc($grapes_query)){
    $grapes_array[]=$grapes['COUNT(*)'];

}

What if in a day, no grapes were found, can I assign "0" to its array value?

Let's say 1/1/2012 = 3 grapes were counted, 1/2/2012 = no grapes were counted, 1/3/2012 = 5 grapes were counted..so the array should be like this.

$grapes_array[0]=3;
$grapes_array[1]= <-- i want to assign a string or number here when a MySQL query is empty.
$grapes_array[2]=3;

i'm getting errors if no value was found.

UPDATE:

fruit names should be grapes...:(

UPDATE 2:

HERE is my sample database being used.

Here is the result I'm getting on your updated query

Answer 1

The updated query will provide dates where there are fruit counts, but no Grapes counted on that day

$grapes_query = mysql_query("SELECT f.fruitDate, IF(ISNULL(f1.count), 0, f1.count) as count FROM tbl_fruits f
    LEFT JOIN (SELECT fruitName, fruitDate, COUNT(*) as count from tbl_fruits d WHERE d.fruitName='Grapes' GROUP BY d.fruitDate) as f1 ON (f.fruitDate = f1.fruitDate) 
    GROUP BY f.fruitDate");
while ($grapes = mysql_fetch_assoc($grapes_query)){
   // use the fruitDate as a key for the array
   $grapes_array[$grapes['fruitDate']]= $grapes['count'];

}

Answer 2

You could do something like this:

• Select the minimum and maximum date from the table
• Fill your output array with date => 0 pairs (initialize every date to zero)
• Run your script, but instead of creating a new numeric index with [] , use the date as a key