问数据库行为空

EN

--create table
local tblTable = [[CREATE TABLE IF NOT EXISTS Testing (id INTEGER PRIMARY KEY,     boompanes);]]
db:exec(tblTable)


--Insert a value for row 1, rows 2-5 are still empty
local tablefill = [[INSERT INTO Testing Values(null,'1')]]
db:exec(tablefill)

--reads database
for row in db:nrows([[SELECT * FROM Testing WHERE id = '2']]) do
   a=a+1
   print("\n\n\n\n\n\n\n"..row.id.."\n\n\n\n\n\n")
     if row.id == nil then

        pak = display.newText("CURRENTLY NIL", 100,200, native.font, 32)
        pak:setFillColor(1,0,0)
        pak.y = pak.y+50*a

    else

        kap = display.newText("NOT NIL", 200,300, native.font, 32)
        kap:setFillColor(0,1,0)
        kap.y = kap.y+50*a
    end

end