Combine multiple MySQL rows into one row

Question

Here's what I am currently getting from my query:

row_no	prospect	hot	contract
1	null	Joe	null
1	John	null	null
1	null	null	Sam

I Am trying to get:

row_no	prospect	hot	contract
1	John	Joe	Sam

I cannot use concate because I still need separate columns

Here's what I have so far...
https://dbfiddle.uk/?rdbms=mysql_8.0&fiddle=e7aab240b40e40955bac44f616d7f3d7

Please note: Ultimately, there will be 7 columns, but a varying amount of rows (ie. the prospect column may have 20 records, where the contract column may only have four or five.

Answer 1

You can do it with conditional aggregation:

WITH CTE_tbl AS
(
  SELECT lead_type,firstname, last_date,
         ROW_NUMBER() OVER(PARTITION BY lead_type order by lead_type Desc) as row_no
  FROM leads
) 
SELECT row_no,
       MAX(case when  lead_type = 'prospect' then firstname end) prospect,
       MAX(case when  lead_type = 'hot' then firstname end) hot,
       MAX(case when  lead_type = 'contract' then firstname end) contract
FROM CTE_tbl
GROUP BY row_no
ORDER BY row_no

See the demo .
Results:

row_no	prospect	hot	contract
1	John	Joe	Sam
2	Mario	Autumn	null
3	Frank	null	null
4	Mary	null	null
5	Steve	null	null