Compare 2 SQL tables, if data does not match, put an integer value in 3rd table

问题

Is there a way to compare 3 sql tables (A, B, C)? Which A and B have columns labled Name, TimeStamp in A, and Name, ScheduledTime in B. I need to compare these 2 columns and if they do not match up, put a numeric value of 1 into column 2 next to the name in table C. I'm fairly new to SQL but wasn't sure if this was possible. (Using SSMS)

Table A looks like this.

Name   |   Time                           
-----------------
John   |   7:00AM
Joe    |   7:07AM
Tim    |   7:25AM

Table B looks like this.

Name   |   Schedule
--------------------
John   |   7:00AM
Joe    |   7:00AM
Tim    |   7:00AM

Table C should look like this.

Name   |   Number
-----------------
John   |   0
Joe    |   1
Tim    |   1

回答1:

For your sample data, the following will work:

select a.name, (case when a.time = b.schedule then 0 else 1 end) as number
into c
from a join
     b
     on a.name = b.name;

It is not clear if that is a general solution, but it works for the provided data.

EDIT:

SQL Fiddle does not seem to be running MS SQL code right now. But here is a SQL Fiddle that I'm confident will show that the above works.

来源：https://stackoverflow.com/questions/34536058/compare-2-sql-tables-if-data-does-not-match-put-an-integer-value-in-3rd-table