Cooper, so far everybody has been silent, which should come as no surprise to you. When you ask a question, you need to be specific and give as all the necessary details. Otherwise you can't expect any useful answers.
Please tell us:
1. Do these databases have the same format, i.e. do they have the same fields, or are they more or less different in design.
2. Would you simply like to add the records of database 2 to database 1, or must they somehow be "mixed".
3. If so, tell us how. There are many different options.
For instance: it is possible that database 1 has a record "A", database 2 also has a record "A" but the data of that record must be read into empty fields of record "A" of database 1.
Or: database 1 has a record "A" which contains data, database 2 also has a record "A" which contains data, but the data of database 2 must replace the data of database 1.
I could give you some more examples, but these two are here to illustrate that unless you provide such information, no one will be able to help you.