Hi
I guess the SQL Server 2012 reached its end of life on July 12, 2022. After this date, Microsoft no longer provides regular security updates and support for SQL Server 2012.
And regarding your question about SQL Server and SQL Express, they generally follow the same support lifecycle. SQL Server editions and have similar support. SQL Server 2014 had mainstream support until July 9, 2019, and extended support until July 9, 2024. SQL Server 2016 had mainstream support until July 13, 2021, and extended support until July 14, 2026. Find below the official documentation on sql 2016 and 2014 for detailed info.
https://learn.microsoft.com/en-us/lifecycle/products/sql-server-2016
https://learn.microsoft.com/en-us/lifecycle/products/sql-server-2014
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