R help - Apr 2018 - merge two data frame based on equal and unequal comparisons

Dear R users,

I need to merge two data frames based on both equal and unequal comparisons. 
The "sqldf" package used to work well , but today, I cannot resolve
the following error by reinstallation of the sqldf package.   Can anyone suggest
a different way to perform this kind of merge function?

Thank you,

Ding
> DMRlog2pbde47DMS <- sqldf("select * from DMR_log2pbde47 as a left
join DMS_log2pbde47 as b
+                            on a.chrom = b.chromosome and a.start <=
b.MAPINFO and a.end >= b.MAPINFO" )
Error in get(as.character(FUN), mode = "function", envir = envir) :
  object 'as.AsIs' of mode 'function' was not found



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HI All,

I found that other R users experienced the same problem when using sqldf
package. An expert provided solution, adding "method="raw" at the
end as below, one or more of the columns in my data.frame are of class
"AsIs" ( I don't know what it is) .  When sqldf retrieves the
result from SQLite it will be numeric or character and since it was originally
of class AsIs,  it tries to convert it back but R provides no as.AsIs,  so it
fails; use method = "raw", so sqldf will not try to convert  the
results from the database.

DMRlog2pbde47DMS <- sqldf("select * from DMR_log2pbde47 as a left join
DMS_log2pbde47 as b
                           on a.chrom = b.chromo and a.start <= b.MAPINFO and
a.end >= b.MAPINFO", method = "raw" )



-----Original Message-----
From: R-help [mailto:r-help-bounces at r-project.org] On Behalf Of Ding, Yuan
Chun
Sent: Wednesday, April 18, 2018 10:38 AM
To: r-help at r-project.org
Subject: [R] merge two data frame based on equal and unequal comparisons

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Dear R users,

I need to merge two data frames based on both equal and unequal comparisons. 
The "sqldf" package used to work well , but today, I cannot resolve
the following error by reinstallation of the sqldf package.   Can anyone suggest
a different way to perform this kind of merge function?

Thank you,

Ding
> DMRlog2pbde47DMS <- sqldf("select * from DMR_log2pbde47 as a left
join
> DMS_log2pbde47 as b
+                            on a.chrom = b.chromosome and a.start <= 
+ b.MAPINFO and a.end >= b.MAPINFO" )
Error in get(as.character(FUN), mode = "function", envir = envir) :
  object 'as.AsIs' of mode 'function' was not found



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-SECURITY/CONFIDENTIALITY WARNING-
This message (and any attachments) are intended solely f...{{dropped:9}}