(Did you ever create the table?)
Try this: ((Not Tested))
local zombie_db = connectToDB()
addEventHandler("onPlayerJoin", getRootElement(), function ()
local x, y, z = getElementPosition(source)
dbExec( zombie_db, "INSERT INTO characters (nume, model, health, posx, posy, posz) VALUES (?,?,?,?,?,?)", getPlayerName(source), getElementModel(source), getElementHealth(source), x, y, z )
end)