In the laboratory, how could you determine if a solid has an ionic bond or a metallic bond?

Metals, because the electrons are delocalized (mobile sea of electrons) are good conductors. So if it conducts electricity as a solid, chances are it's a metal. (Of course graphite is also a good conductor, but that's a nonmetal. Different things going on there.)

Ionic solids have positive and negative ions trapped together in a crystal lattice. These solids are NOT good conductors. If you melt an ionic solid or dissolve it in water, then the ions are free and able to move around, and it will become a good electrolyte.

Generally speaking, ionic solids have high melting points because they require a lot of energy to break up those strong ionic bonds. The melting points of metals vary widely, so there's no easy way to predict what that number is going to be.

You can dissolve the compound in water, and if the solution conducts electricity, it was an ionic compound; if it does not conduct electricity, it was a covalent compound.

Hu da whata?

Test if the solid conducts electricity. If it does, it is a metal and will have the metallic bond.

Dissolve the solid in water. If it does not conduct electricity when solid, but does conduct when dissolved, then it is ionic and it will have ionic bonds.

If the substance won't conduct  electricity when solid or dissolved in water, it is probably a covalent solid.