How do you input data from sql into a specific datagridview cell based on column date and name in c# winforms

Question

I have a table in my database that stores data entry. theres a name column where each persons name is inserted as they scan a serial number, 3 middle columns for serial entry and the last column is the date. database sample:

i have a winform with a datagridview that populates the dates in the column header for every day of the month. what i am trying to figure out is how to populate the distinct name along with the count of their serial numbers based on what day it is in the datagridview. i can populate the names but the serial counts on specific days is getting me. Here is what my winform looks like:

and the code:

DateTime dt = DateTime.Now;
                var startDate = new DateTime(dt.Year, dt.Month, 1);
                int days = DateTime.DaysInMonth(dt.Year, dt.Month);
                for (int i = 0; i < days; i++)
                {
                    dataGridView1.Columns.Add("clm_" + startDate.ToShortDateString(), startDate.ToString("dd-MMM"));
                    startDate = startDate.AddDays(1);
                }
                using (SqlConnection sqlConnection = new SqlConnection(@"connection"))
                {
                    SqlCommand sqlCmd = new SqlCommand("SELECT DISTINCT NAME FROM repair_data_entry", sqlConnection);
                    sqlConnection.Open();
                    SqlDataReader sqlReaderName = sqlCmd.ExecuteReader();
                    while (sqlReaderName.Read())
                    {
                        dataGridView1.Rows.Add(sqlReaderName["NAME"].ToString());
                    }
                    sqlReaderName.Close();
                    
                }

what i need to do is pull the serial count per day per tech. like Bill Berrys serial count for a specific day shows up in that specific cell. it may be a thing where i need to set the database up differently, i don't know. and that wouldn't be a problem. i should note there aren't specific names either. there's going to be 20-30 names that change on a daily basis so my intent was something dynamic.

EDIT:

I've been fiddling with SQL fiddler and I found the query that works, However. I had to hard code the dates? How would I make them dynamic based on what's in the CREATED column since techs will be entering in data on a daily basis?

Here's the query:

SELECT NAME AS TECH,   
[12/1/2020], [12/2/2020]  
FROM  
(SELECT NAME, REP, CREATED  
    FROM repair_data_entry) AS SourceTable  
PIVOT  
(  
COUNT(REP)  
FOR CREATED IN ([12/1/2020], [12/2/2020])  
) AS PivotTable;

http://sqlfiddle.com/#!18/8bc96/1

Answer 1

I figured out the sql Query:

    DECLARE @Date AS VARCHAR(MAX),
        @query AS VARCHAR(MAX)
        
select @dATE = STUFF((SELECT ',' + QUOTENAME(REPLACE(CONVERT(VARCHAR(10), CREATED, 101), '-', '/')) 
                    from repair_data_entry
                    group by CREATED
                    ORDER BY CREATED
            FOR XML PATH(''), TYPE
            ).value('.', 'VARCHAR(MAX)') 
        ,1,1,'')

SET @query = 'SELECT NAME AS TECH, ' + @Date + ' 
  
FROM  
(SELECT NAME, CREATED, REP  
    FROM repair_data_entry) AS S  
PIVOT  
(  
COUNT(REP)  
FOR CREATED IN ('+@Date+')  
) P'
EXECUTE(@query)

This does exactly what I want. so that answers that. sqlFiddle

can anyone point me in the direction to change the date style to "MM / dd / yyyy"?

EDIT: found the answer. updated query