Overview

There are two dimensions in the Core View Collection that provide lists of students: StudentSchoolDim View and StudentLocalEducationAgencyDim View. These dimension provide student names and a few key demographic values with cardinality of one (e.g., student recorded with a single "sex"). For demographic information with cardinality "many" (e.g., student record with multiple tribal affiliations or multiple languages), the Core Collection provides a DemographicsDim  and two bridge views that link the student dimensions to the demographic dimension: StudentSchoolDemographicsBridge View and  StudentLocalEducationAgencyDemo. This article illustrates the relationships between these views and demonstrates realistic usage scenarios. 

Design Note

Why are there two similar views (StudentSchoolDim View and StudentLocalEducationAgencyDim View), instead of a single StudentDim ?

• We wanted to include demographic / enrollment information directly in the Student dimension.
• In the Ed-Fi Data Standard v3.x, demographic information can be recorded either on the school relationship or the local education agency (LEA) relationship.
• To create a single view, we would have to coalesce the data, choosing either the school or LEA information as the primary information.
• Which one is primary? It depends on the implementation.
  → Combining into a single view would oversimplify the necessary complexity in the Ed-Fi ODS database and lead to incorrect results in some implementations.

In short, we decided that it's better to be transparent than to disguise this challenging point.

Data Model

Enrollment

School Enrollment

"Lander Middle School" has school key 628530001. The following query shows us that there are 320 students enrolled at the school:

select
    count(1)
from
    analytics.StudentSchoolDim
where
    schoolkey = 628530001

Because the Analytics Middle Tier is not a temporal solution, there is no way to ask the question "How many students were enrolled yesterday?" The views are returning data student-school data for right now. 

Local Education Agency Enrollment

Lander Middle School's LocalEducationAgencyKey is 628530, Lander ISD. Another simple query gives us the current enrollment in this school district:

select
    count(1)
from
    analytics.StudentLocalEducationAgencyDim
where
    StudentLocalEducationAgencyDim.LocalEducationAgencyKey = 628530

The answer is: 320. Apparently Lander ISD only has a middle school, as confirmed by the script below: 

select
    *
from
    analytics.SchoolDim
where
    LocalEducationAgencyKey = 628530

Now let's find a better example: What is the enrollment for each school in a district? This time we'll use the Glendale ISD local education agency, with key 867530:

select
    LocalEducationAgencyDim.LocalEducationAgencyName,
    SchoolDim.SchoolName,
    count(1) as Enrollment
from
    analytics.LocalEducationAgencyDim
inner join
    analytics.SchoolDim
inner join
    analytics.StudentSchoolDim
on
    SchoolDim.SchoolKey = StudentSchoolDim.SchoolKey
on
    LocalEducationAgencyDim.LocalEducationAgencyKey = SchoolDim.LocalEducationAgencyKey
where
    LocalEducationAgencyDim.LocalEducationAgencyKey = 867530
group by
    LocalEducationAgencyDim.LocalEducationAgencyName,
    SchoolDim.SchoolName

select
    edOrgLea.NameOfInstitution as LocalEducationAgencyName,
    edOrgSchool.NameOfInstitution as SchoolName,
    count(1) as Enrollment
from
    edfi.StudentSchoolAssociation
inner join
    edfi.School
on
    StudentSchoolAssociation.SchoolId = School.SchoolId
inner join
    edfi.EducationOrganization edOrgSchool
on
    School.SchoolId = edOrgSchool.EducationOrganizationId
inner join
    edfi.EducationOrganization edOrgLea
on
    School.LocalEducationAgencyId = edOrgLea.EducationOrganizationId
where
    edOrgLea.EducationOrganizationId = 867530
group by
    edOrgLea.NameOfInstitution,
    edOrgSchool.NameOfInstitution

Demographics

School

How do we access student demographics, for example, around language use? The following query gives the count of students by language and school, using the Analytics Middle Tier.

SELECT
    SchoolDim.SchoolName AS 'School name',
    DemographicDim.DemographicLabel AS 'Language',
    COUNT(1) AS 'Number of students'
FROM
    analytics.StudentSchoolDim
INNER JOIN
    analytics.StudentSchoolDemographicsBridge
ON
    StudentSchoolDim.StudentSchoolKey = StudentSchoolDemographicsBridge.StudentSchoolKey
INNER JOIN
    analytics.DemographicDim
ON
    StudentSchoolDemographicsBridge.DemographicKey = DemographicDim.DemographicKey
INNER JOIN
    analytics.SchoolDim
ON
    StudentSchoolDim.SchoolKey = SchoolDim.SchoolKey
WHERE
    DemographicDim.DemographicParentKey = 'Language'
GROUP BY
    SchoolDim.SchoolName,
    DemographicDim.DemographicLabel

We can write a similar query without Analytics Middle Tier and it does not require much more effort. However, that query is different between Data Standard v2.2 and Data Standard v3.x, because the old edfi.StudentLanguage  table is now StudentEducationOrganizationAssociationLanguage. This one query on Analytics Middle Tier is now portable across Ed-Fi ODS / API versions since v2.3, without requiring a rewrite.

select
    distinct DemographicParentKey
from
    analytics.DemographicDim

/*
DemographicParentKey
---------------------
CohortYear
Disability
DisabilityDesignation
Language
LanguageUse
Race
StudentCharacteristic
TribalAffiliation
*/

Local Education Agency

As discussed in the overview of this article, demographics in Data Standard v3.x can be stored either with the student's relationship to the school, or the relationship with the local education agency. The above query can be rewritten for district-level information:

SELECT
    LocalEducationAgencyDim.LocalEducationAgencyName,
    DemographicDim.DemographicLabel AS 'Language',
    COUNT(1) AS 'Number of students'
FROM
    analytics.StudentLocalEducationAgencyDim
INNER JOIN
    analytics.StudentLocalEducationAgencyDemographicsBridge
ON
    StudentLocalEducationAgencyDim.StudentLocalEducationAgencyKey = StudentLocalEducationAgencyDemographicsBridge.StudentLocalEducationAgencyKey
INNER JOIN
    analytics.DemographicDim
ON
    StudentLocalEducationAgencyDemographicsBridge.DemographicKey = DemographicDim.DemographicKey
INNER JOIN
    analytics.LocalEducationAgencyDim
ON
    StudentLocalEducationAgencyDim.LocalEducationAgencyKey = LocalEducationAgencyDim.LocalEducationAgencyKey
WHERE
    DemographicDim.DemographicParentKey = 'Language'
GROUP BY
    LocalEducationAgencyDim.LocalEducationAgencyName,
    DemographicDim.DemographicLabel

The query is nearly identical, requiring only two changes:

• StudentSchoolDim  → StudentLocalEducationAgencyDim 
• StudentSchoolDemographicsBridge  → StudentLocalEducationAgencyDemographicsBridge .