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Editorial Team
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Asked: 2026-06-17T11:02:57+00:00

I have a complex data structure I am working with and I am not

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I have a complex data structure I am working with and I am not quite sure how to tackle it in a single SQL query, although my gut tells me this should be possible to do.

The essence of what I am doing is trying to display the results of available plans for a given vendor based on the selected hardware model. The results should adhere to only possible combinations, and the plans contain restrictions which are currently stored as key/value pairs in a restrictions table. Below is a simplification of what I am working with:

(I will use a wireless device analogy since almost everyone is familair with cell phones)

models Table

model_id
vendor_id
is_data
is_voice
is_4g
is_3g

Sample Data:

model_id,vendor_id,is_data,is_voice,is_4g,is_3g
DeviceA,Sprint,1,1,0,1
DeviceB,Sprint,1,0,1,0
DeviceC,Sprint,0,1,0,0
DeviceD,Sprint,0,1,0,0
DeviceE,Sprint,0,1,0,0
DeviceF,Verizon,1,1,0,1
DeviceG,Verizon,1,0,1,0
DeviceH,Verizon,0,1,0,0
DeviceI,Verizon,0,1,0,0
DeviceJ,Verizon,0,1,0,0
DeviceK,Tmobile,1,1,0,1
DeviceL,Tmobile,1,0,1,0
DeviceM,Tmobile,0,1,0,0
DeviceN,Tmobile,0,1,0,0
DeviceO,Tmobile,0,1,0,0

plans Table

plan_id
vendor_id
name

Sample Data:

plan_id,vendor_id,name
PlanA,Sprint,Big Data Only Plan
PlanB,Verizon,Small Data Only Plan
PlanC,Sprint,300 Min Plan
PlanD,Verizon,900 Min Plan
PlanE,Verizon,Big Data Only Plan
PlanF,Tmobile,Small Data Only Plan
PlanG,Tmobile,300 Min Plan
PlanH,Tmobile,1000 Min Plan

plan_restrictions Table

restriction_id
vendor_id
plan_id
type
value

Sample Data:

restriction_id,vendor_id,plan_id,type,value
1,Sprint,PlanA,radio,3G
2,Sprint,PlanA,device_type,data
3,Verizon,PlanB,radio,4G
4,Sprint,PlanC,radio,3G
5,Sprint,PlanC,device_type,voice
6,Verizon,PlanD,radio,3G
7,Verizon,PlanD,device_type,voice
8,Verizon,PlanE,radio,3G
9,Verizon,PlanE,device_type,voice
10,Tmobile,PlanF,device_type,data
11,Tmobile,PlanG,device_type,voice
12,Tmobile,PlanH,device_type,voice

Restrictions keyed (I have closer to 50 actually, here is a same type of representation):

type / value possibilities
radio / 3g, 4g
device_type / data, voice

I am open to the possibility of restructuring the tables to make it easier to re-query, however I need to retain a certain amount of flexibility since I do have about 1000 models, 1000 plans, and about 2000 restrictions.

I personally think there is some sort of structure issue here, ie. models perhaps should have their elements as key/value pairs in a separate table, but that is even more complexity, and I haven’t determined yet how to properly apply data driven restrictions in the first place.

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1 Answer

  1. Editorial Team

    I kicked this around for about the last hour with the other dba’s here and think I solved it. I am posting this for anyone who finds themselves in a similar situation. The biggest problem was that I was too close to the data, and was trying enforce “meaningful” properties and restrictions between the plans needs and the models properties.. which isn’t really necessary.

    I can restructure my data to be in the following tables:

    • Plans
    • Restrictions
    • Models
    • Plans would have a many to many relationship to Restrictions
    • Models would have a many to many relationship to Restrictions

    I would solve the many to many relationships with intirum tables

    • Plans_Restrictions
    • Models_Restrictions

    This would allow me to have stupid “Restrictions” such as a “Red Thing”

    I would query as a chain:

    • Plans
    • Plans_Restrictions
    • Restrictions
    • Models_Restrictions
    • Models

    ie. To get all models with their properties information (restriction info) that are eligible for a plan I could use:

    SELECT 
    M.* 
    ,R.*
FROM (
    SELECT P1.*
    FROM Plans P1
    WHERE id_vendor = @id_vendor
) P

INNER JOIN Plans_Restrictions PR
ON P.plan_id = PR.plan_id

INNER JOIN Restrictions R
ON PR.property = R.property

INNER JOIN Model_Restrictions MR
ON R.property = MR.property

INNER JOIN Model M
ON MR.model_id = M.model_id

    And to get all the plans that are eligible for a model, i would reverse the 5 table chained join.

    Thanks Abe.. writing this all down in detail to explain it, and understanding why your suggestion didn’t solve my problem really helped me understand what my problem was and what I really needed to do. I don’t think I would have solved it so fast without you.

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