DatabaseMetaData.getIndexInfo() return wrong NON_UNIQUE value

[fanste]

Driver version

13.2.0.jre11

SQL Server version

Microsoft SQL Server 2017 (RTM-CU31-GDR) (KB5058714) - 14.0.3495.9 (X64) Jun 10 2025 16:22:03

Problem description

According to the docs, sp_statistics contains NON_UNIQUE with 1 = not unique and 0 = unique.
But sys.indexes contains is_unique with 1 = unique and 0 = not unique.

DatabaseMetaData.getIndexInfo() simply merges the results of both result without handling this difference.

This e.g. causes hibernate-tools to fail on reverse engineering the database model to entity classes, as the same index name may be unique and non-unique at the same time.

[fanste]

The PR #2763 also includes a fix for this issue, see https://github.com/microsoft/mssql-jdbc/pull/2763/files#diff-4a3a77772520f23ef4afb8cc585d19563f9ff6dc30021ca7f281f46d2d91f70eR284