Question

I am trying to get data from one row in a table into three rows in a temp table, so I can update the data based on values in a different, and I am wondering if there is a better approach than doing a UNION operation.

Here is the basic UNION syntax that gets the data from one row into the three rows I want:

    (SELECT 
    0 as lead_id,
    'RV' as lead_type,
    '' as lead_serial,
    rv_amplitude as amplitude,
    rv_pulse_width as pulse_width,
    rv_sensitivity as sensitivity
    FROM program_parameters WHERE event_id = 33636)
    UNION
    (SELECT
    0 as lead_id,
    'LV' as lead_type,
    '' as lead_serial,
    final_amplitude as amplitude,
    final_pulse_width as pulse_width.
    final_sensitivity as sensitivity
    FROM program_parameters WHERE event_id = 33636)
    UNION
    (SELECT
    0 as lead_id,
    'ATRIAL' as lead_type,
    atrial_amplitude as amplitude,
    atrial_pulse_width as pulse_width,
    atrial_sensitivity as sensitivity
    FROM program_parameters WHERE event_id = 33636)

so that my final data is a three row table with columns.

The only key value I have to get this data is the event_id, and there is only one row per event_id in the table.

Is there a better way to get this data into separate rows other than a UNION operation?

Answer 1

UNION is the right solution here.

This is what you need to use when you want to have separate result sets as one set.