In analyzing the September 2020 PatentView Database, I observed an anomaly in the data integration between the 'g_ipc_at_issue' table and the 'g_patent' table, , particularly in the tracking of International Patent Classification (IPC) counts by year. Notably, the 'ipc_sequence' values within the 'g_ipc_at_issue' table, corresponding to the 'patent_date' from the 'g_patent' table, uniformly register as '0' for the years 2002, 2003, and 2004. This uniformity raises questions about data accuracy, as illustrated by Patent 6335051 (issued in 2002), which is categorized under three IPCs but also exhibits a '0' ipc_sequence value.