tiny_tds failed at the second execute

Question

Today, tiny_tds suddenly does not accept more than one execute and returns:

C:\>ruby test_use.rb
one
two
C:/test_use.rb:15:in `execute': Attempt to initiate a new Adaptive Server operation with results pending (TinyTds::Error)
    from C:/test_use.rb:15

The code is simply as three USEs:

require 'rubygems'
require 'yaml'
require 'fastercsv'
require 'tiny_tds'
require 'iconv'

CONFIG = YAML.load_file("config.yml")

client = TinyTds::Client.new(:username => CONFIG["db"]["username"], :password => CONFIG["db"]["password"], 
  :host => CONFIG["db"]["server"], :database => CONFIG["db"]["database"])

puts "one"
client.execute("USE DATAFEED")
puts "two"
client.execute("USE DATAFEED")
puts "three"
client.execute("USE DATAFEED")

Any clue what is the problem? I tried rebooting the Windows machine already.

Answer 1

You have to terminate the execute with a do:

Client.execute("...").do

Answer 2

Here is an example of how I do it.

results = $regcenter_db.execute("select top 10 * from events")
event_ids = results.collect { |i| i["event_id"] }
results.do    

Answer 3

You have to call do OR cancel. If you are doing something like getting a partial results, and you are not interested in execute the do method you can call cancel to abort the query.

Answer 4

According to the documentation for TinyTds on GitHub:

It is important that you either return the data from the query, most likely with the #each method, or that you cancel the results before asking the client to execute another SQL batch. Failing to do so will yield an error.

To cancel the query, use the cancel method:

client.execute("USE DATAFEED").cancel