ctci/14. Databases/14.1. Multiple apartments.md

45 lines
809 B
Markdown

# 14.1. Multiple apartments
> Write a SQL query to get a list of tenants who are renting more than one apartment
| Apartments | |
|-|-|
| AptID | int |
| UnitNumber | varchar(10) |
| BuildingID | int |
| Buildings | |
|-|-|
| BuildingID | int |
| ComplexID | int |
| BuildingName | varchar(100) |
| Address | varchar(500) |
| Requests | |
|-|-|
| RequestID | int |
| Status | varchar(100) |
| AptID | int |
| Description | varchar(500) |
| Complexes | |
|-|-|
| ComplexID | int |
| ComplexName | varchar(100) |
| AptTenants | |
|-|-|
| TenantID | int |
| AptId | int |
| Tenants | |
|-|-|
| TenantID | int |
| TenantName | varchar(100) |
```sql
SELECT TenantName FROM Tenants
INNER JOIN (SELECT TenantID FROM AptTenants GROUP BY TenantID HAVING count(*) > 1) C
ON Tenants.TenantID == C.TenantID
```