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#shell and #sqlThese are two new directives that can be used in scripts with ploticus 2.00 and higher. They both work similary, and can either stream results into the script, or set variables. #shell is an interface for running external commands and capturing the results. #sql will allow ploticus to operate as a client to SQL databases, and works with pocketSQL. Interface to other databases (MySQL, Oracle, etc.) is not yet available; code contributions are sought in these areas (see dbinterface.c).STREAMING DATAHere is an example of how #sql is to be used with proc getdata :#proc getdata delim: tab data: #sql #dumptab select * from trialresults where trialnum = @TRIALNUM For longer SQL commands a multi-line construct is available: #proc getdata delim: tab data: #sql #dumptab select trialnum, age, sex, weight, time1, time2 from trialresults where trialnum = @TRIALNUM and trialdate = @TDATE #endsqlThe #shell directive can be used similary, but this is redundant since proc getdata already has a command attribute. SETTING VARIABLESThese directives may be used to set variables for plot labels, etc. For example:#sql #load select fullname from tsyms where tickersym = @TSYM #proc annotate location: min max-0.2 text: @fullname Here is an example where the results of a shell command may be used to set variables: // submit the command.. #shell #processrows cat mydata | grep "^Jan" // get one result rows and parse out fields.. #call $shellrow( A, B, C ) #proc annotate location: min max-0.2 text: @A @B DRIVING LOOPSThese directives may be used to drive loops that iterate once per row of results. For example:// get a list of cases #sql #processrows select caseid from cases #while $sqlrow() = 0 // get data for a case #proc getdata delim: tab data: #sql2 #dumptab select * from casedata where caseid = @caseid ... plot the case #endloop
#shell
may be used similary.
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