mirror of
https://github.com/taosdata/TDengine
synced 2026-05-24 10:09:01 +00:00
79e1a7bcf8
Malloc memory to store Lua state and callback function from Lua. Connector can support multiple connection by this way. Memory will be freed when connection isn't established successfully or connection is closed by lua call. Stream content in Lua is not the same one with stream content in connector. A loop in test code do the job for continuous query. record is inserted between query actions.
125 lines
3.1 KiB
Lua
125 lines
3.1 KiB
Lua
local driver = require "luaconnector"
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local host="127.0.0.1"
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local user="root"
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local password="taosdata"
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local db =nil
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local port=6030
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local conn
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local res = driver.connect(host,user,password,db,port)
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if res.code ~=0 then
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print(res.error)
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return
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else
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conn = res.conn
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end
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local res = driver.query(conn,"drop database demo")
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res = driver.query(conn,"create database demo")
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if res.code ~=0 then
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print(res.error)
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return
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end
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res = driver.query(conn,"use demo")
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if res.code ~=0 then
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print(res.error)
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return
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end
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res = driver.query(conn,"create table m1 (ts timestamp, speed int,owner binary(20))")
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if res.code ~=0 then
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print(res.error)
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return
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end
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res = driver.query(conn,"insert into m1 values ('2019-09-01 00:00:00.001',0,'robotspace'), ('2019-09-01 00:00:00.002',1,'Hilink'),('2019-09-01 00:00:00.003',2,'Harmony')")
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if res.code ~=0 then
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print(res.error)
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return
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else
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print("insert successfully, affected:"..res.affected)
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end
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res = driver.query(conn,"select * from m1")
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if res.code ~=0 then
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print("select error:"..res.error)
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return
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else
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print("in lua, result:")
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for i = 1, #(res.item) do
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print("timestamp:"..res.item[i].ts)
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print("speed:"..res.item[i].speed)
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print("owner:"..res.item[i].owner)
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end
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end
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res = driver.query(conn,"CREATE TABLE thermometer (ts timestamp, degree double) TAGS(location binary(20), type int)")
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if res.code ~=0 then
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print(res.error)
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return
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end
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res = driver.query(conn,"CREATE TABLE therm1 USING thermometer TAGS ('beijing', 1)")
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if res.code ~=0 then
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print(res.error)
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return
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end
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res = driver.query(conn,"INSERT INTO therm1 VALUES ('2019-09-01 00:00:00.001', 20),('2019-09-01 00:00:00.002', 21)")
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if res.code ~=0 then
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print(res.error)
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return
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else
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print("insert successfully, affected:"..res.affected)
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end
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res = driver.query(conn,"SELECT COUNT(*) count, AVG(degree) AS av, MAX(degree), MIN(degree) FROM thermometer WHERE location='beijing' or location='tianjin' GROUP BY location, type")
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if res.code ~=0 then
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print("select error:"..res.error)
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return
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else
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print("in lua, result:")
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for i = 1, #(res.item) do
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print("res:"..res.item[i].count)
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end
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end
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function callback(t)
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print("continuous query result:")
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for key, value in pairs(t) do
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print("key:"..key..", value:"..value)
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end
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end
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local stream
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res = driver.open_stream(conn,"SELECT COUNT(*) as count, AVG(degree) as avg, MAX(degree) as max, MIN(degree) as min FROM thermometer interval(2s) sliding(2s);)",0,callback)
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if res.code ~=0 then
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print("open stream error:"..res.error)
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return
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else
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print("openstream ok")
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stream = res.stream
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end
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--From now on we begin continous query in an definite (infinite if you want) loop.
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local loop_index = 0
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while loop_index < 20 do
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local t = os.time()*1000
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local v = loop_index
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res = driver.query(conn,string.format("INSERT INTO therm1 VALUES (%d, %d)",t,v))
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if res.code ~=0 then
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print(res.error)
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return
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else
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print("insert successfully, affected:"..res.affected)
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end
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os.execute("sleep " .. 1)
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loop_index = loop_index + 1
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end
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driver.close_stream(stream)
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driver.close(conn)
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