How do I match two large files to find matching telephone numbers

[Guest]

We are a call center that receives very large lists of business telephone
numbers. The lists are scrubbed by the company we work with, they then send
back a text file with just the telephone numbers and many records missing and
others with approval to call them. We need to find a way to match the
scrubbed list to the master list.

Any suggestions?

 

[John Vinson]

We are a call center that receives very large lists of business telephone
numbers. The lists are scrubbed by the company we work with, they then send
back a text file with just the telephone numbers and many records missing and
others with approval to call them. We need to find a way to match the
scrubbed list to the master list.

Any suggestions?

Import both lists into Access Tables (with the telephone number field
indexed); create a Query joining the two tables.

If "very large" means fewer than 10,000,000 or so phone numbers per
list this should be quite practical.

John W. Vinson[MVP]

 

[Armen Stein]

Import both lists into Access Tables (with the telephone number field
indexed); create a Query joining the two tables.

If "very large" means fewer than 10,000,000 or so phone numbers per
list this should be quite practical.

John W. Vinson[MVP]

To elaborate, the type of join between Master and Scrubbed will tell you
different things.

An inner join (no arrowheads) will show you all the phone numbers that
match on both sides (master and scrubbed).

If the arrow points toward the scrubbed table, you'll get every master
record, and you can look at the fields from the scrubbed table to see
whether the number is there. If the scrubbed fields are Null, the
number is missing.

If the arrow points toward the master table, you'll get every scrubbed
record, and you can look at the fields from the master table to see
whether the number is there. If the master fields are Null, then you
have a number in scrubbed that isn't in the master.