Merging two unrelated datasetts

Hello all,

I apologize in advance if I am posting incorrectly, I am new to SQLTeam. I am seeking help with an issue I've been having in combing unrelated data from different sources(databases) and no unique key for join

The table schemas in the current systems are completely different to the new system. Reports are currently running using the current system.

The trouble is when the new system is roll out, those reports will break but, we don't want that.

I’ve identufied all the tables in the current system into a staging tables. The issues now is how to combine the data into a single table so that there won't be impact when the new system is roll out.

Do anyone know the strategy to combine these data either in SSIS or SQL. Though the tables schemas are different there are some element of relationships between the systems but the primaryKeys or some field might not exist. The current system will need to be transform to accommodate the old system.

Thanking you in advnace.


First figure out how you would match the two sets of data if you could afford to do it manually by examining each row and making a determination based on whatever criteria that you want to use. Write down the rules and exceptions and anything else that is relevant. Once you know what those rules that you (as a human being) used, then it should be possible to translate those rules to T-SQL so you don't have to do the manual labor.