lua对sqlite数据库操作封装

DB = {}
db_e = require "luasql.sqlite3"

function open_db( ... )
-- body
env = assert(db_e.sqlite3())
db =assert(env:connect("test.db"))
end

function DB.query(sql)
-- body
open_db()
local res = assert(db:execute(sql))
local tb = {}
local t = {}
local i = 1
while(nil ~= res:fetch(t, 'a')) do
tb[i] = {}
tb[i] = t
t = {}  --must
end
res:close()
close_db()
return tb    --tb每个元素都是一个table
end

function DB.exec(sql)
-- body
open_db()
assert(db:execute(sql))
close_db()
end

function close_db( ... )
-- body
db:close()
env:close()
end

return DB