number of days calculation using different format variable

[NoorulIyn]

This was a question asked in a interview.Can someone help me

A study database contains a treatment table table (TREAT) with Subject ID

(SUBJID) and treatment start date (TRTSDT) and a subject status table (STAT)

with Subject ID (SUBJID), Subject Status (STATUS) and Status Update Date

(STATUSDT). The treatment table has one row per patient.  The subject status

table has at least one row per patient.  Merge the two tables and select the

most recent record to provide the last know subject status and the number of

days to the last status update.  Formats from the database are provided below.

TREAT                       |    STAT

                           |

SUBJID      TRTSDT          |    SUBJID       STATUS        STATUSDT

<8.0>       <datetime22.>   |    <8.0>        <$15.>        <date9.>

[Reeza]

Use DatePART() function to convert datetime to date and subtract the two.