(insert|update)_dtv_multiplex debug output does not include values being updated

[Nick Morrott <knowledgejunkie (at) gmail (dot) com>]

The VB_CHANSCAN output emitted to the logfile when insert_dtv_multiplex() in called (line 193 of mythtv/libs/libmythtv/channelutil.cpp) does not contain the actual values of the settings being inserted/updated. Instead, the string contains the names of the variables being bound in the SQL query but not their values.

This results in the log being "spammed" with the following duplicated line for each channel added (and for DVB-S, this can be several hundred channels).

INSERT INTO dtv_multiplex   (sourceid,        sistandard,        frequency,  modulation, transportid, networkid, symbolrate, bandwidth, polarity, inversion, transmission_mode, fec, constellation, hierarchy, hp_code_rate, lp_code_rate, guard_interval, mod_sys, rolloff) VALUES   (:SOURCEID,      :SISTANDARD,       :FREQUENCY1, :MODULATION, :TRANSPORTID, :NETWORKID, :SYMBOLRATE, :BANDWIDTH, :POLARITY, :INVERSION, :TRANS_MODE, :INNER_FEC, :CONSTELLATION, :HIERARCHY, :HP_CODE_RATE, :LP_CODE_RATE, :GUARD_INTERVAL, :MOD_SYS, :ROLLOFF);

The log of a full UK DVB-T scan which includes this is attached to #8731

[robertm]

Nick, can you please test this patch?

[robertm]

Output last executed query in logging of channel scanner.

[robertm]

(In [26188]) Change the logging of insert and update in VB_CHANSCAN to display bound values-- haven't actually tested this, but it ought to fix #8733.

[Nick Morrott <knowledgejunkie <at> gmail <dot> com>]

In testing with a debug build of r26195, the update did not fix the issue but replaced each bound variable's name with a question mark. First few inserts follow:

2010-09-10 08:44:59.348 New DB DataDirect connection
2010-09-10 08:44:59.349 Connected to database 'mythconverg' at host: localhost
2010-09-10 08:44:59.351 insert_dtv_multiplex(1, 'dvb', 746000000, auto, 24576, 9018...) mplexid:0
2010-09-10 08:44:59.352 insert_dtv_multiplex -- insert 0
INSERT INTO dtv_multiplex   (sourceid,        sistandard,        frequency,  modulation, transportid, networkid, symbolrate, bandwidth, polarity, inversion, transmission_mode, fec, constellation, hierarchy, hp_code_rate, lp_code_rate, guard_interval, mod_sys, rolloff) VALUES   (?,      ?,       ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?);

2010-09-10 08:44:59.352 insert_dtv_multiplex -- inserted 1
Insert(dvb): 18
2010-09-10 08:44:59.355 insert_dtv_multiplex(1, 'dvb', 746000000, auto, 24576, 9018...) mplexid:1
2010-09-10 08:44:59.356 insert_dtv_multiplex -- update 1
UPDATE dtv_multiplex SET frequency    = ?, modulation       = ?, symbolrate       = ?, bandwidth        = ?, polarity         = ?, inversion        = ?, transmission_mode= ?, fec              = ?, constellation    = ?, hierarchy        = ?, hp_code_rate     = ?, lp_code_rate     = ?, guard_interval   = ?, mod_sys          = ?, rolloff          = ? WHERE sourceid    = ?      AND       sistandard  = ?    AND  transportid = ? AND networkid = ? 

Insert(dvb): 21
2010-09-10 08:44:59.359 insert_dtv_multiplex(1, 'dvb', 746000000, auto, 24576, 9018...) mplexid:1
2010-09-10 08:44:59.360 insert_dtv_multiplex -- update 1
UPDATE dtv_multiplex SET frequency    = ?, modulation       = ?, symbolrate       = ?, bandwidth        = ?, polarity         = ?, inversion        = ?, transmission_mode= ?, fec              = ?, constellation    = ?, hierarchy        = ?, hp_code_rate     = ?, lp_code_rate     = ?, guard_interval   = ?, mod_sys          = ?, rolloff          = ? WHERE sourceid    = ?      AND       sistandard  = ?    AND  transportid = ? AND networkid = ? 

Insert(dvb): 12
2010-09-10 08:44:59.363 insert_dtv_multiplex(1, 'dvb', 746000000, auto, 24576, 9018...) mplexid:1
2010-09-10 08:44:59.364 insert_dtv_multiplex -- update 1
UPDATE dtv_multiplex SET frequency    = ?, modulation       = ?, symbolrate       = ?, bandwidth        = ?, polarity         = ?, inversion        = ?, transmission_mode= ?, fec              = ?, constellation    = ?, hierarchy        = ?, hp_code_rate     = ?, lp_code_rate     = ?, guard_interval   = ?, mod_sys          = ?, rolloff          = ? WHERE sourceid    = ?      AND       sistandard  = ?    AND  transportid = ? AND networkid = ? 

On a more general note, why does the log output not include the channel data being inserted (which is always different) and instead duplicate the same multiplex information a dozen or more times? Would it not be more useful to first log the list of muxes being inserted/updated, and then log the list of channels being inserted from the scan?

[Stuart Auchterlonie]

I'll look at this over the weekend

[robertm]

(In [26357]) Remove a bit of logging regard channel insert and updates entirely. It occurs to me that if you really want to see what the DB is doing, you should be using the VB_DATABASE verbosity anyway, in which case the bound values will be visible. Fixes #8733.