  We review and compare different variational formulations for the
Schr\"{o}dinger field. Some of them rely on the addition of a conveniently
chosen total time derivative to the hermitic Lagrangian. Alternatively, the
Dirac-Bergmann algorithm yields the Schr\"{o}dinger equation first as a
consistency condition in the full phase space, second as canonical equation in
the reduced phase space. The two methods lead to the same (reduced)
Hamiltonian. As a third possibility, the Faddeev-Jackiw method is shown to be a
shortcut of the Dirac method. By implementing the quantization scheme for
systems with second class constraints, inconsistencies of previous treatments
are eliminated.
