How to Retrieve the First Workflow for Each Sales Representative in SQL?

Retrieving the Initial Workflow for Each Sales Representative

This SQL query efficiently retrieves the first workflow record for each sales representative within the current month and year. The data is sourced from two tables: SM_Employee and SM_SalesRepWorkflow.

The solution utilizes the ROW_NUMBER() window function. This function assigns a unique rank to each row within a defined partition (in this case, each sales representative) based on a specified order (here, the workflowid).

Here's the SQL query:

SELECT *
FROM (
    SELECT 
        workflowid, 
        salesRepId, 
        quantityAssigned, 
        quantityLeft, 
        month, 
        year,
        ROW_NUMBER() OVER (PARTITION BY salesRepId ORDER BY workflowid) AS rownumber
    FROM SM_SalesRepWorkflow
) ranked_workflows
WHERE rownumber = 1;

This query first assigns a row number to each workflow for each sales representative, ordered by workflowid. The outer query then filters this result set, selecting only those rows with rownumber = 1, effectively returning the first workflow for each salesRepId.

Example Data and Results:

Given this sample data from SM_SalesRepWorkflow:

Workflowid	SalesRepId	QuantityAssigned	QuantityLeft	Month	Year
WF_101	EMP_101	100	90	May	2013
WF_102	EMP_101	100	70	May	2013
WF_101	EMP_102	100	100	May	2013
WF_101	EMP_103	100	80	May	2013

The query will return:

Workflowid	SalesRepId	QuantityAssigned	QuantityLeft	Month	Year
WF_101	EMP_101	100	90	May	2013
WF_101	EMP_102	100	100	May	2013
WF_101	EMP_103	100	80	May	2013

This accurately reflects the first workflow for each sales representative. Note that this approach assumes workflowid provides a meaningful ordering for determining the "first" workflow. If a different ordering is needed, adjust the ORDER BY clause accordingly.

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