MYSQL employee working hours for each day in date range - mysql

Question

Hi I have a MySQL query that looks into a table that holds hours for each day the employee work. My query looks at the day of the date and the result is what hours we worked. so let say 2015-11-24 is Tuesday then 8.
How do I run the query without PHP to look at every day in a date range?
Thanks
Eg. $holidaystart = '2015-11-24';
$holidayend = '2015-11-30';
#Table employees hours id Mon Tue Wed Thu Fri Sat Sun
1 8 8 0 8 8 8 0
$sql= "select empId,
'".$holidayStart."' as date,
case dayname('".$holidayStart."')
when 'Sunday' then Sun
when 'Monday' then Mon
when 'Tuesday' then Tue
when 'Wednesday' then Wed
when 'Thursday' then Thu
when 'Friday' then Fri
when 'Saturday' then Sat
else 0 end as hours
from employees" ;
Edit
I have one table that holds employee id number (empId) Then each day of the week Mon, Tue, Wed, Thu, Fri, Sat, Sun
--------------------------------------------------------------
| empid | Mon | Tue | Wed | Thu | Fri | Sat | Sun |
--------------------------------------------------------------
| 1 | 8 | 8 | 0 | 8 | 8 | 8 | 0 |
| 2 0 8 | 8 0 | 8 | 8 | 8 |
--------------------------------------------------------------
so employee 1 as a working shift of 8 hour on Mon, 8 on Tue, 0 Wed, 8 Thu, 8 Fri, 8 Sat 0 Sunday . So what I am trying to achieve is to look at lets say 2015-11-24 to 2015-11- 26 and see how many hours are employee 1 will work between the 2 date based on how many hours they are suppose to work in each day Mon = 8 hour shift Tue = 8 hour shift Wed = 0 (day off) Thu = 8 Fri = 8 Sat = 8 Sun day off
FIDDLE DEMO
As you can see by the demo 2015-10-10 is saturday so empId 1 = 8 hours empId 2 = 6 hours and empId 3 = 8 hours so how do i do this using a date range?

Answer 1

Assuming your table has the following columns:
empId - Employee id
workDate - the date they worked
hoursWorked - the number of hours they worked that day
Then something like this
SELECT empId
SUM(IF(dayname(workDate) = 'Sunday', hoursWorked, 0)) As Sun,
SUM(IF(dayname(workDate) = 'Monday', hoursWorked, 0)) As Mon,
SUM(IF(dayname(workDate) = 'Tuesday', hoursWorked, 0)) As Tues,
SUM(IF(dayname(workDate) = 'Wednesday', hoursWorked, 0)) As Wed,
SUM(IF(dayname(workDate) = 'Thursday', hoursWorked, 0)) As Thurs,
SUM(IF(dayname(workDate) = 'Friday', hoursWorked, 0)) As Fri,
SUM(IF(dayname(workDate) = 'Saturday', hoursWorked, 0)) As Sat,
FROM employees
GROUP BY empId
WHERE workDate BETWEEN :startDate AND :endDate
Don't forget to use prepared statements to protect yourself from SQL injection!

Answer 2

Ok, so this is a blind shot, because you haven't provided us with the structure of table employees. Try to following:
$sql = mysql_query('SELECT * FROM employees WHERE `date` BETWEEN ".$startDate.'" AND "'.$endDate.'"');
while($row=mysql_fetch_assoc($sql)){
$arr[$row[date]]=$row;
}
$totalHours=0;
for($i=strtotime($startDate);$i<=strtotime($endDate);$i+=86400){
$day=$arr[date('Y-m-d H:i:s',$i];
if($day){
$id=$day[id];
}
$hours=($day)? $day[hours] : 0;
$totalHours+=$hours;
echo "Employee $id Day ".date('D',$i). " Hours $hours";
}
echo "Total hours $totalHours";
You shouldn't use the mysql library and instead use mysqli or PDO.

Answer 3

Try this dynamic Pivot query:
SET #sql = NULL;
SELECT empId,
GROUP_CONCAT(DISTINCT
CONCAT(case dayname(table_date_field)
when 'Sunday' then Sun
when 'Monday' then Mon
when 'Tuesday' then Tue
when 'Wednesday' then Wed
when 'Thursday' then Thu
when 'Friday' then Fri
when 'Saturday' then Sat
else 0 end as hours
)
) INTO #sql
FROM employees;
SET #sql = CONCAT('SELECT empId,', #sql, ' FROM employees GROUP BY empId');