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About
The FreeSWITCH Database Handler (freeswitch.Dbh) allows you to connect to databases from your Lua script. The advantage of this method is that it makes use of connection pooling provided by FreeSWITCH which gives a nice increase in speed when compared to creating a new TCP connection for each LuaSQL env:connect().
Here are some examples for using freeswitch.Dbh in a mod_lua script.
Ft
Example Dialplan App
Here is a simple way to get a few variables from your db and set them as channel variables:
Assume you have a table did_users in your db with only 2 columns: did and user with a unique key over both.
XML Dialplan
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<extension name="map_did_to_user" continue="true">
<condition field="destination_number" expression="^(\+|00)(\d+)$">
<action inline="true" application="lua" data="map_did_to_user.lua $2"/>
</condition>
</extension>
<extension name="if_user_then_">
<condition field="${user}" expression="... |
| Note |
|---|
Note that the lua script must be run inline, so that the retrieved channel variables are available immediately. |
Lua Script
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-- map_did_to_user.lua
-- takes DID as first argument
local did = argv[1]
local dbh = freeswitch.Dbh("odbc://datasourcename:username:password")
local function set_session_variables(row)
-- Sets session variables with the same names as the columns from the database
for key, val in pairs(row) do
if session then
session:setVariable(key, val)
end
freeswitch.consoleLog("DEBUG", string.format("set(%s=%s)\n", key, val))
end
end
assert(dbh:connected())
local sql_query = "SELECT user FROM did_users WHERE did = " .. did
assert(dbh:query(sql_query, set_session_variables)) |
The script checks if a session is available. If it is, the key/value will be set as a channel variable. The result will always be printed to your console in the debug level.
Example User Directory XML
The following script is a simple way to use an SQL query to generate User Directory XML on the fly inside FreeSWITCH.
It's assumed you have a table named users in your database containing the following columns: domain, id, mailbox, number-alias, password, dial-string and user_context (all varchars).
Lua Configuration
You can enable sending XML directory lookups through Lua by adding the following lines to your lua.conf.xml:
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<param name="xml-handler-script" value="gen_dir_user_xml.lua"/> <param name="xml-handler-bindings" value="directory"/> |
Lua Script
Based on the mailing list: http://lists.freeswitch.org/pipermail/freeswitch-users/2012-January/079296.html there are problems with Voicemail Inject when using Lua to serve configs (as well as personal experience), i will elaborate on this more in depth - Destreyf
...
| Note |
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Note that the query in the example is formatted for MySQL; use double-quotes (") instead of backticks (`) for PostgreSQL. |
db_connect.lua rewrite
Chapter 7 of the FreeSWITCH book explains a db_connect.lua script. This is a rewrite not using LuaSQL. I used a simple MS-Access database (freeswitch.accdb) to test the script.
| Code Block |
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-- db_connect.lua
-- Connects to a database using freeswitch.Dbh connection pooling, checks PIN, reads balance
-- A hangup function makes the code a bit cleaner
local dbh = freeswitch.Dbh("odbc://datasourcename:username:password")
local row = {}
function hangup_call ()
session:streamFile("ivr/ivr-thank_you.wav")
session:sleep(250)
session:streamFile("voicemail/vm-goodbye.wav")
session:hangup()
end
if dbh:connected() == false then
freeswitch.consoleLog("notice", "gen_dir_user_xml.lua cannot connect to database" .. dsn .. "\n")
hangup_call()
end
-- Set invalid entry file
invalid = "ivr/ivr-that_was_an_invalid_entry.wav"
-- Greet caller
session:answer()
session:streamFile("ivr/ivr-hello.wav")
tries = 0
while (tries < 3) do
-- Collect account number
acct = session:playAndGetDigits(3, 5, 3, 7000, "#", "phrase:enter_message_number", invalid, ".+")
if (acct) then
-- Pull account from database -> assumes that acct is unique
my_query = "select * from users where acct = " .. acct
assert(dbh:query(my_query, function(qrow)
for key, val in pairs(qrow) do
row[key] = val
end
end))
end
-- Confirm that we received the record
if (row.pin ~= nil) then
-- We have an account, now collect PIN and check
tries = 0
while (tries < 3) do
pin = session:playAndGetDigits(3, 5, 3, 7000, "#", "ivr/ivr-please_enter_pin_followed_by_pound.wav", invalid, "\\d+")
if (row.pin == pin) then
user_repeat = true
while(user_repeat == true) do
session:streamFile("voicemail/vm-you_have.wav")
session:sleep(200)
session:say(row.balance, "en", "currency", "pronounced")
session:sleep(200)
-- "to repeat these options, please press 1"
digits = session:playAndGetDigits(1,1,3,7000,"#",
"file_string://ivr/ivr-to_repeat_these_options.wav!ivr/ivr-please.wav!voicemail/vm-press.wav!digits/1.wav",
invalid,"\\d+")
-- repeat y/n
freeswitch.consoleLog("INFO","User entered '" .. digits .. "'\n")
if (digits == "1") then
user_repeat = true
else
hangup_call()
break
end
end
else
-- Callerr entered wrong PIN
session:streamFile("ivr/ivr-that_was_an_invalid_entry.wav")
tries = tries + 1;
end
end
if (tries > 2) then
-- Too many failed attempts to enter PIN
session:streamFile("voicemail/vm-abort.wav")
hangup_call()
break
end
else
-- We did not find this account
session:streamFile(invalid)
tries = tries + 1;
end
end -- while (tries < 3)
if (tries > 2) then
session:streamFile("voicemail/vm-abort.wav")
hangup_call()
end |
See Also
