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Re^3: Database processing

by davidrw (Prior)
on Aug 06, 2005 at 02:37 UTC ( #481425=note: print w/replies, xml ) Need Help??


in reply to Re^2: Database processing
in thread DBI::st=HASH output

hmm... print out $avgSQL and make sure it's valid sql. If there's anything funky (/\W/) in the column names they'll need to be escaped.

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Re^4: Database processing
by DrAxeman (Scribe) on Aug 06, 2005 at 02:48 UTC
    I printed $avgSQL and got:
    SELECT avg(PDH_CSV40_EasternDaylightTime_240_) as PDH_CSV40_EasternDay +lightTime_240_, avg(ERWWCOMMUNITIES_Memory_Pages_sec) as ERWWCOMMUNIT +IES_Memory_Pages_sec, avg(ERWWCOMMUNITIES_NetworkInterface_CompaqEthe +rnet_FastEthernetAdapter_Module_BytesTotalPERsec) as ERWWCOMMUNITIES_ +NetworkInterface_CompaqEthernet_FastEthernetAdapter_Module_BytesTotal +PERsec, avg(ERWWCOMMUNITIES_NetworkInterface_MSTCPLoopbackinterface_B +ytesTotalPERsec) as ERWWCOMMUNITIES_NetworkInterface_MSTCPLoopbackint +erface_BytesTotalPERsec, avg(ERWWCOMMUNITIES_NetworkInterface_CompaqE +thernet_FastEthernetAdapter_Module_CurrentBandwidth) as ERWWCOMMUNITI +ES_NetworkInterface_CompaqEthernet_FastEthernetAdapter_Module_Current +Bandwidth, avg(ERWWCOMMUNITIES_NetworkInterface_MSTCPLoopbackinterfac +e_CurrentBandwidth) as ERWWCOMMUNITIES_NetworkInterface_MSTCPLoopback +interface_CurrentBandwidth, avg(ERWWCOMMUNITIES_PhysicalDisk_0C_PCTDi +skTime) as ERWWCOMMUNITIES_PhysicalDisk_0C_PCTDiskTime, avg(ERWWCOMMU +NITIES_PhysicalDisk_1D_PCTDiskTime) as ERWWCOMMUNITIES_PhysicalDisk_1 +D_PCTDiskTime, avg(ERWWCOMMUNITIES_PhysicalDisk_Total_PCTDiskTime) as + ERWWCOMMUNITIES_PhysicalDisk_Total_PCTDiskTime, avg(ERWWCOMMUNITIES_ +PhysicalDisk_Total_AvgDiskQueueLength) as ERWWCOMMUNITIES_PhysicalDis +k_Total_AvgDiskQueueLength, avg(ERWWCOMMUNITIES_Processor_Total_PCTPr +ocessorTime) as ERWWCOMMUNITIES_Processor_Total_PCTProcessorTime, avg +(ERWWDC1_Memory_PagesPERsec) as ERWWDC1_Memory_PagesPERsec, avg(ERWWD +C1_NetworkInterface_IntelPRO_100NetworkConnection_BytesTotalPERsec) a +s ERWWDC1_NetworkInterface_IntelPRO_100NetworkConnection_BytesTotalPE +Rsec, avg(ERWWDC1_NetworkInterface_MSTCPLoopbackinterface_BytesTotalP +ERsec) as ERWWDC1_NetworkInterface_MSTCPLoopbackinterface_BytesTotalP +ERsec, avg(ERWWDC1_NetworkInterface_IntelPRO_100NetworkConnection_Cur +rentBandwidth) as ERWWDC1_NetworkInterface_IntelPRO_100NetworkConnect +ion_CurrentBandwidth, avg(ERWWDC1_NetworkInterface_MSTCPLoopbackinter +face_CurrentBandwidth) as ERWWDC1_NetworkInterface_MSTCPLoopbackinter +face_CurrentBandwidth, avg(ERWWDC1_PhysicalDisk_0C_PCTDiskTime) as ER +WWDC1_PhysicalDisk_0C_PCTDiskTime, avg(ERWWDC1_PhysicalDisk_Total_PCT +DiskTime) as ERWWDC1_PhysicalDisk_Total_PCTDiskTime, avg(ERWWDC1_Phys +icalDisk_Total_AvgDiskQueueLength) as ERWWDC1_PhysicalDisk_Total_AvgD +iskQueueLength, avg(ERWWDC1_Processor_Total_PCTProcessorTime) as ERWW +DC1_Processor_Total_PCTProcessorTime, avg(ERWWNAB_Memory_PagesPERsec) + as ERWWNAB_Memory_PagesPERsec, avg(ERWWNAB_NetworkInterface_Intel825 +5x_basedIntegratedFastEthernet_BytesTotalPERsec) as ERWWNAB_NetworkIn +terface_Intel8255x_basedIntegratedFastEthernet_BytesTotalPERsec, avg( +ERWWNAB_NetworkInterface_MSTCPLoopbackinterface_BytesTotalPERsec) as +ERWWNAB_NetworkInterface_MSTCPLoopbackinterface_BytesTotalPERsec, avg +(ERWWNAB_NetworkInterface_Intel8255x_basedIntegratedFastEthernet_Curr +entBandwidth) as ERWWNAB_NetworkInterface_Intel8255x_basedIntegratedF +astEthernet_CurrentBandwidth, avg(ERWWNAB_NetworkInterface_MSTCPLoopb +ackinterface_CurrentBandwidth) as ERWWNAB_NetworkInterface_MSTCPLoopb +ackinterface_CurrentBandwidth, avg(ERWWNAB_PhysicalDisk_0C_PCTDiskTim +e) as ERWWNAB_PhysicalDisk_0C_PCTDiskTime, avg(ERWWNAB_PhysicalDisk_T +otal_PCTDiskTime) as ERWWNAB_PhysicalDisk_Total_PCTDiskTime, avg(ERWW +NAB_PhysicalDisk_Total_AvgDiskQueueLength) as ERWWNAB_PhysicalDisk_To +tal_AvgDiskQueueLength, avg(ERWWNAB_Processor_Total_PCTProcessorTime) + as ERWWNAB_Processor_Total_PCTProcessorTime, avg(ERWWSEARCH_Memory_P +agesPERsec) as ERWWSEARCH_Memory_PagesPERsec, avg(ERWWSEARCH_NetworkI +nterface_BroadcomNetXtremeGigabitEthernetDriver_BytesTotalPERsec) as +ERWWSEARCH_NetworkInterface_BroadcomNetXtremeGigabitEthernetDriver_By +tesTotalPERsec, avg(ERWWSEARCH_NetworkInterface_IntelPRO_100NetworkCo +nnection_BytesTotalPERsec) as ERWWSEARCH_NetworkInterface_IntelPRO_10 +0NetworkConnection_BytesTotalPERsec, avg(ERWWSEARCH_NetworkInterface_ +MSTCPLoopbackinterface_BytesTotalPERsec) as ERWWSEARCH_NetworkInterfa +ce_MSTCPLoopbackinterface_BytesTotalPERsec, avg(ERWWSEARCH_NetworkInt +erface_BroadcomNetXtremeGigabitEthernetDriver_CurrentBandwidth) as ER +WWSEARCH_NetworkInterface_BroadcomNetXtremeGigabitEthernetDriver_Curr +entBandwidth, avg(ERWWSEARCH_NetworkInterface_IntelPRO_100NetworkConn +ection_CurrentBandwidth) as ERWWSEARCH_NetworkInterface_IntelPRO_100N +etworkConnection_CurrentBandwidth, avg(ERWWSEARCH_NetworkInterface_MS +TCPLoopbackinterface_CurrentBandwidth) as ERWWSEARCH_NetworkInterface +_MSTCPLoopbackinterface_CurrentBandwidth, avg(ERWWSEARCH_PhysicalDisk +_0CD_PCTDiskTime) as ERWWSEARCH_PhysicalDisk_0CD_PCTDiskTime, avg(ERW +WSEARCH_PhysicalDisk_Total_PCTDiskTime) as ERWWSEARCH_PhysicalDisk_To +tal_PCTDiskTime, avg(ERWWSEARCH_PhysicalDisk_Total_AvgDiskQueueLength +) as ERWWSEARCH_PhysicalDisk_Total_AvgDiskQueueLength, avg(ERWWSEARCH +_Processor_Total_PCTProcessorTime) as ERWWSEARCH_Processor_Total_PCTP +rocessorTime, avg(ERWWSQLWEB_Memory_PagesPERsec) as ERWWSQLWEB_Memory +_PagesPERsec, avg(ERWWSQLWEB_NetworkInterface_BroadcomNetXtremeGigabi +tEthernetDriver_BytesTotalPERsec) as ERWWSQLWEB_NetworkInterface_Broa +dcomNetXtremeGigabitEthernetDriver_BytesTotalPERsec, avg(ERWWSQLWEB_N +etworkInterface_MSTCPLoopbackinterface_BytesTotalPERsec) as ERWWSQLWE +B_NetworkInterface_MSTCPLoopbackinterface_BytesTotalPERsec, avg(ERWWS +QLWEB_NetworkInterface_BroadcomNetXtremeGigabitEthernetDriver_Current +Bandwidth) as ERWWSQLWEB_NetworkInterface_BroadcomNetXtremeGigabitEth +ernetDriver_CurrentBandwidth, avg(ERWWSQLWEB_NetworkInterface_MSTCPLo +opbackinterface_CurrentBandwidth) as ERWWSQLWEB_NetworkInterface_MSTC +PLoopbackinterface_CurrentBandwidth, avg(ERWWSQLWEB_PhysicalDisk_0CD_ +PCTDiskTime) as ERWWSQLWEB_PhysicalDisk_0CD_PCTDiskTime, avg(ERWWSQLW +EB_PhysicalDisk_Total_PCTDiskTime) as ERWWSQLWEB_PhysicalDisk_Total_P +CTDiskTime, avg(ERWWSQLWEB_PhysicalDisk_Total_AvgDiskQueueLength) as +ERWWSQLWEB_PhysicalDisk_Total_AvgDiskQueueLength, avg(ERWWSQLWEB_Proc +essor_Total_PCTProcessorTime) as ERWWSQLWEB_Processor_Total_PCTProces +sorTime FROM results
    It looks OK to me, but then again, I'm a novice at SQL.
    I do a lot of preprocessing to the csv files before I run them through the perl script. I remove spaces, , , (, ), etc... the list above has all column names in it. I'm wondering if this should be looped? These csv files will average about 30 columns and upto 6000 rows. Doing all the average calculations in one command may be a little taxing on my system.

    PS. I don't need the data after the average is calculated. Just the column name and the average. Also, I don't need the first column, that can just go away.
      You can tweak the map to be map { "avg($_) as $_\n" } to make it a little more legible, and then browse for errors. Did you try running the SQL directly in your db? What about a portion (e.g. w/just a few columns) of it?

      If you want to exclude columns, simply grep them out of @cols, or to just ditch the first one, do a shift @cols;
      Doing all the average calculations in one command may be a little taxing on my system.
      No, doing all the average calculations in many commands is what will tax your system. If you do it in separate statements, you're making the database go through all 6000 rows 30 different times. But if you do it in one statement, it only needs one pass.
        I've tried the SQL in earlier versions of this script, and I had no luck using an AS statement. When I run the script now I get:
        SQL ERROR: Bad set function before FROM clause. Execution ERROR: No command found!. $VAR1 = undef;
        When I remove the AS statement:
        my $sth = $dbh->prepare("SELECT * FROM results WHERE 1=0"); $sth->execute; my @cols = @{$sth->{NAME}}; shift @cols; my $avgSQL = 'SELECT ' . join(', ', map { "avg($_) \n" } @cols ) . ' FROM results'; my $avgsHashRef = $dbh->selectrow_hashref($avgSQL);
        I get
        Execution ERROR: Can't use AVG on a string! called from ./runsql3.sql +at 24. DBD::CSV::db selectrow_hashref failed: Attempt to fetch row from a Non +-SELECT statement [for Statement "SELECT avg(ERWWCOMMUNITIESMemoryPag +essec) , avg(ERWWCOMMUNITIESNetworkInterfaceCompaqEthernetFastEthernetAdapter +ModuleBytesTotalPERsec) , avg(ERWWCOMMUNITIESNetworkInterfaceMSTCPLoopbackinterfaceBytesTotalP +ERsec) , avg(ERWWCOMMUNITIESNetworkInterfaceCompaqEthernetFastEthernetAdapter +ModuleCurrentBandwidth) , avg(ERWWCOMMUNITIESNetworkInterfaceMSTCPLoopbackinterfaceCurrentBand +width) , avg(ERWWCOMMUNITIESPhysicalDisk0CPCTDiskTime) , avg(ERWWCOMMUNITIESPhysicalDisk1DPCTDiskTime) , avg(ERWWCOMMUNITIESPhysicalDiskTotalPCTDiskTime) , avg(ERWWCOMMUNITIESPhysicalDiskTotalAvgDiskQueueLength) , avg(ERWWCOMMUNITIESProcessorTotalPCTProcessorTime) , avg(ERWWDC1MemoryPagesPERsec) , avg(ERWWDC1NetworkInterfaceIntelPRO100NetworkConnectionBytesTotalPER +sec) , avg(ERWWDC1NetworkInterfaceMSTCPLoopbackinterfaceBytesTotalPERsec) , avg(ERWWDC1NetworkInterfaceIntelPRO100NetworkConnectionCurrentBandwi +dth) , avg(ERWWDC1NetworkInterfaceMSTCPLoopbackinterfaceCurrentBandwidth) , avg(ERWWDC1PhysicalDisk0CPCTDiskTime) , avg(ERWWDC1PhysicalDiskTotalPCTDiskTime) , avg(ERWWDC1PhysicalDiskTotalAvgDiskQueueLength) , avg(ERWWDC1ProcessorTotalPCTProcessorTime) , avg(ERWWNABMemoryPagesPERsec) , avg(ERWWNABNetworkInterfaceIntel8255xbasedIntegratedFastEthernetByte +sTotalPERsec) , avg(ERWWNABNetworkInterfaceMSTCPLoopbackinterfaceBytesTotalPERsec) , avg(ERWWNABNetworkInterfaceIntel8255xbasedIntegratedFastEthernetCurr +entBandwidth) , avg(ERWWNABNetworkInterfaceMSTCPLoopbackinterfaceCurrentBandwidth) , avg(ERWWNABPhysicalDisk0CPCTDiskTime) , avg(ERWWNABPhysicalDiskTotalPCTDiskTime) , avg(ERWWNABPhysicalDiskTotalAvgDiskQueueLength) , avg(ERWWNABProcessorTotalPCTProcessorTime) , avg(ERWWSEARCHMemoryPagesPERsec) , avg(ERWWSEARCHNetworkInterfaceBroadcomNetXtremeGigabitEthernetDriver +BytesTotalPERsec) , avg(ERWWSEARCHNetworkInterfaceIntelPRO100NetworkConnectionBytesTotal +PERsec) , avg(ERWWSEARCHNetworkInterfaceMSTCPLoopbackinterfaceBytesTotalPERsec +) , avg(ERWWSEARCHNetworkInterfaceBroadcomNetXtremeGigabitEthernetDriver +CurrentBandwidth) , avg(ERWWSEARCHNetworkInterfaceIntelPRO100NetworkConnectionCurrentBan +dwidth) , avg(ERWWSEARCHNetworkInterfaceMSTCPLoopbackinterfaceCurrentBandwidth +) , avg(ERWWSEARCHPhysicalDisk0CDPCTDiskTime) , avg(ERWWSEARCHPhysicalDiskTotalPCTDiskTime) , avg(ERWWSEARCHPhysicalDiskTotalAvgDiskQueueLength) , avg(ERWWSEARCHProcessorTotalPCTProcessorTime) , avg(ERWWSQLWEBMemoryPagesPERsec) , avg(ERWWSQLWEBNetworkInterfaceBroadcomNetXtremeGigabitEthernetDriver +BytesTotalPERsec) , avg(ERWWSQLWEBNetworkInterfaceMSTCPLoopbackinterfaceBytesTotalPERsec +) , avg(ERWWSQLWEBNetworkInterfaceBroadcomNetXtremeGigabitEthernetDriver +CurrentBandwidth) , avg(ERWWSQLWEBNetworkInterfaceMSTCPLoopbackinterfaceCurrentBandwidth +) , avg(ERWWSQLWEBPhysicalDisk0CDPCTDiskTime) , avg(ERWWSQLWEBPhysicalDiskTotalPCTDiskTime) , avg(ERWWSQLWEBPhysicalDiskTotalAvgDiskQueueLength) , avg(ERWWSQLWEBProcessorTotalPCTProcessorTime) FROM results"] at ./runsql3.sql line 24. $VAR1 = undef;
        Same error if I trim down the sql statement. I have also re-looked at my csv file and the columns data is numeric. I'm stumped!

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