Thank you everyone for your assistance.  I was able to resolve this issue by concatenating the string variable to the query statement.
string[200] select_string, variable_string, query_string;
variable_string =  "= '" + #field + "'";
select_string = "select Column5 from Table where Column1 = 'EDI' and Column2 ";
query_string = select_string + variable string;
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Karen Gallello
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                                                Original Message:
Sent: Thu February 13, 2020 02:42 AM
From: Clayton Snyman
Subject:  User Exit to Query External Database
Good day Karen,
We were able to successfully implement what you are trying to do.
- We wrote a java class that has methods manages the database connection and executes sql queries.
- This class will be installed as a 3rd party jar on SI.
- In the map we declared Object variable that will invoke the different methods that are needed from database.
Let me know if you need more details.
Regards
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Clayton Snyman
Original Message:
Sent: Mon February 10, 2020 04:14 PM
From: Karen Gallello
Subject: User Exit to Query External Database
Hi - I'm creating a map where the input is EDI and the output is SQL.  I am trying to query a DB2 database table on the input side of the map in order to get the cross-reference value of the N104 data. 
This works  (Where ABCD is the N104 value):Select Column5 from Table where Column1 = 'EDI' and Column2 = "ABCD"
This does not work  (Where variable = N104 value):Select Column5 from Table where Column1 = 'EDI' and Column2 = variable
Does anyone know how to accomplish what I'm trying to do?
Any assistance would be greatly appreciated!
Thank you - Karen 
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Karen Gallello
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#B2BIntegration