When people connect a report directly to an ERP's tables, two problems appear. The raw tables are hard to understand, with cryptic names and codes. And any change to the ERP, such as an upgrade or a new field, can quietly break every report built on them. SQL views are a simple pattern that solves both.
What a view is
A view is a saved query that looks like a table. A report reads from the view, and the view reads from the real tables. If the underlying structure changes, you update the view once and the reports keep working.
The pattern
Keep reporting objects separate from the source tables, in their own schema, such as one called reporting. Create a dedicated read-only login for reports, with permission only to that schema, so a report cannot change data or see more than it should. Then build views named for what they mean to the business, such as sales orders, customers or inventory on hand, not for what the ERP calls them.
What the views should do
Rename columns into plain language. Translate codes into descriptions, for example turning a status of 3 into shipped. Filter out test records and cancelled rows according to agreed rules. Handle blanks sensibly. Convert dates and units into consistent forms. Join the tables that always go together, so report authors do not repeat the same join in every report.
This is where your business definitions get written down once. If a report author asks what counts as an active customer, the answer is in the view.
Keep them simple
Views built on views built on views become slow and impossible to debug. Aim for a small number of layers, comment what each does, and avoid selecting every column when a report needs five.
Watch the load on the live system
A view does not store anything. It runs against the live tables each time it is read. A heavy query run at the wrong moment can slow down the people entering orders. Schedule heavy reports for quiet periods, use read-only replicas or a copy of the database where you can, and check what your ERP vendor allows. Some vendors have rules about querying their database directly.
Test them against the ERP
After building a view, compare its totals with a standard report from the ERP itself. If they match, you have evidence it is right. If they do not, you have found a definition to settle.
Document and version them
Keep the view definitions in version control or at least in a shared document, with a note of who owns each and when it last changed. When something breaks after an upgrade, you want to know exactly what changed.
When views are not enough
Views work well for current, single-system reporting. If you need history, data from several systems or heavy analysis, the better answer is a separate reporting database fed from your sources, as described in what ETL is and when you need it and why built-in ERP reports are not enough.
For the connection side, see connecting your BI tool to your ERP without depending on IT, and for keeping queries fast, SQL Server performance tuning for non-DBAs.
If your reports connect straight to ERP tables and you are nervous about the next upgrade, reach out. A reporting layer of views is often a quick and low-risk fix.
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