I have to design a query that details the # of patients readmitted to a hospital within 30 days of their last discharge.
Each patient has a separate record in the database for each visit.
For example,

Table:Inpatient
Record Number    AdmitDate   DischDate
1683             2/3/10      4/8/11
1683             5/8/11      5/9/11
1680             12/1/10     1/18/11
2369             8/9/10      10/1/10
2369             10/15/10    11/4/10

I've read some forums that suggested doing a min/max feature, but not quite sure how to use.

Any help would be appreciated.

Thank you