$dbHandle->errstr is object-oriented syntax,
$DBI::errstr is procedural syntax. In theory,
calling errstr using a dbHandle
should return the last error on that handle and calling it
through the DBI module should return the last
error seen anywhere in the database. But, given that
Many programs only use a single database connection
Many database engines only preserve a single error
message per client
You should check your error messages immediately, before
going on to another database operation