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sqlrformattingrodbc

Is there a better way to code this sqlQuery in R?


I'm writing an R script to get some database data and then do stuff with it, using the RODBC package. Currently all my sqlQuery commands are one long string;

stsample<-sqlQuery(odcon, paste"select * from bob.DESIGNSAMPLE T1, bob.DESIGNSUBJECTGROUP T2, bob.DESIGNEVENT T3, bob.CONFIGSAMPLETYPES T4 WHERE T1.SUBJECTGROUPID = T2.SUBJECTGROUPID AND T1.TREATMENTEVENTID = T3.TREATMENTEVENTID AND T1.SAMPLETYPEKEY = T4.SAMPLETYPEKEY AND T1.STUDYID = T2.STUDYID AND T1.STUDYID = T3.STUDYID AND T1.STUDYID = ", chstudid, sep=""))
head(stsample)

which looks ugly and is hard to read/update. I've tried putting them multiline, but then new line characters get in the way, currently my best is this using lots of paste's;

stsample<-sqlQuery(odcon,
    paste(
        "select ",
            "* ", 
        "from ", 
            "BOB.DESIGNSAMPLE T1, ",
            "BOB.DESIGNSUBJECTGROUP T2, ",
            "BOB.DESIGNEVENT T3, ",
            "BOB.CONFIGSAMPLETYPES T4 ",
        "WHERE ",
            "T1.SUBJECTGROUPID = T2.SUBJECTGROUPID ",
            "AND T1.TREATMENTEVENTID = T3.TREATMENTEVENTID ",
            "AND T1.SAMPLETYPEKEY = T4.SAMPLETYPEKEY ",
            "AND T1.STUDYID = T2.STUDYID ",
            "AND T1.STUDYID = T3.STUDYID ",
            "AND T1.STUDYID = ",chstudid,
        sep="")
    )
head(stsample)

But I don't like having to put quotes around everyline, and getting my whitespace correct. Is there a better way ?


Solution

  • I would use something like this:

    stsample<-sqlQuery(odcon,
        paste("
    ####DATASET CONSTRUCTION QUERY #########
        select 
        *  
        from 
        BOB.DESIGNSAMPLE T1, 
        BOB.DESIGNSUBJECTGROUP T2, 
        BOB.DESIGNEVENT T3, 
        BOB.CONFIGSAMPLETYPES T4 
        WHERE 
        T1.SUBJECTGROUPID = T2.SUBJECTGROUPID 
        AND T1.TREATMENTEVENTID = T3.TREATMENTEVENTID 
        AND T1.SAMPLETYPEKEY = T4.SAMPLETYPEKEY 
        AND T1.STUDYID = T2.STUDYID 
        AND T1.STUDYID = T3.STUDYID 
        AND T1.STUDYID = 
    ###################################   
        ", as.character(chstudid), sep="")
        )