you know in nucleophilic substituion where a nucleophile such as an OH attatcks a haloalkane and gives it its lone pair of electrons to form a bond with it ..would it be WRONG to say it forms a DATIVE COVALENT BOND with it..because the lone pair of electrons are coming from one atom (i.e. the OH)..which is basically what dative covalent bonding is...
The idea of a dative bond is somewhat useless...... It came up in my A-level course, but it has been discarded almost casually in my degree course. The practicalities of the idea are somewhat awkward as you can't actually track a specific electron., and the bond doesn't care where the electrons came from.
It has more relevance in coordination chemistry, where the lone pairs of ligands donate some electron density to the center metal.
In a sense it is a dative bond.... the lone pair orbital overlaps with antibonding orbital of the c-halogen bond. Electrons from the bond move to the halogen while the new orbital forming has electrons, originally localised on the oxygen, shared between the carbon and oxygen although unevenly. Of course the product is essentially a protonated alcohol which will loose a proton to form a neutral species.