Displaying 20 results from an estimated 11000 matches similar to: "sqldf Date problem"
2009 Feb 20
2
importing data to SQLite database with sqldf
Hi all,
I am attempting to learn SQL through sqldf...
One task I am particularly interested in is merging separate
(presumably large) files into a single table without loading these
files into R as an intermediate step (by loading them into SQLite and
merging them there).
Taking a step back, I've considered these alternatives:
1) I know if I use straight SQLite commands I might use the
2010 Jul 16
1
sqldf modify table
Hi - I am something of a newbie and am a little perplexed. When (trying to)
modify a table I issue the following commands with subsequent errors
sqldf("alter table Korea drop column code", dbname = "mydb")
error in statement: near "drop": syntax error
or
sqldf("alter table Korea rename column hyr to hyrI", dbname = "mydb")
error in statement:
2011 Jul 14
1
SQldf with sqlite and H2
SQldf with sqlite and H2
I have a large csv file (about 2GB) and wanted to import the file into R and do some filtering and analysis. Came across sqldf ( a great idea and product) and was trying to play around to see what would be the best method of doing this. csv file is comma delimited with some columns having comma inside the quoation like this "John, Doe".
I tried this first
2010 Jan 26
1
[Fwd: Re: question on sqldf syntax]
Sorry mistake from me. This was another problem in my mind , but with
RMySQL.
Christian
> library(RMySQL)
> library(sqldf)
> sqldf("Select * from mtcars")
Fehler in mysqlNewConnection(drv, ...) :
RS-DBI driver: (Failed to connect to database: Error: Access denied
for user 'user'@'localhost' (using password: NO)
)
Fehler in if (dbname ==
2012 Feb 02
9
sqldf for Very Large Tab Delimited Files
Hi All,
I have a very (very) large tab-delimited text file without headers. There
are only 8 columns and millions of rows. I want to make numerous pieces of
this file by sub-setting it for individual stations. Station is given as in
the first column. I am trying to learn and use sqldf package for this but am
stuck in a couple of places.
To simulate my requirement, I have taken iris dataset as an
2010 Nov 01
1
sqldf error only on Unix not Windows
Hello Group,
I am having trouble with the sqldf package on unix. The same code works fine on windows.
Silly Example script:
# Load the package
library(sqldf)
# Use the titanic data set
data(women)
colnames(women)
head(women)
sqldf('select height, count(*) from women where height is not null group by weight')
Unix Output and error:
bash-3.00$ R --vanilla <testR.R
2012 Jan 23
1
sqldf + Date class. Ordering and summary statistics appear to be incorrect.
I've been using sqldf heavily lately but have encountered problems
with ordering of observations or calculating statistics such as max()
and min() when the variable used is of class Date.
For example, if I run the following code:
=============== begin code =================
library(sqldf)
2011 Mar 02
1
a question on sqldf's handling of missing value and factor
Dear subscribers:
I am using the following code to read a large number of big text files:
library(sqldf)
tempd <- file(XXXX)
tempdx <- sqldf("select * from tempd", dbname = tempfile(), file.format =
list(header = T, sep="\t", row.names = F))
The problem is: all my numberical variable become factor (maybe because
these columns all contain missing value). It would be
2009 Jan 06
1
sqldf with date (class date) variables ?
Hello,
I am having trouble with retrieving some data in queries involve with variables
with data type "date". See the enclosed example:
ll<-c("21DEC2006","15DEC2006")
ss<-data.frame(ll)
ss<-transform(ss,ll=as.date(as.character(ll)))
(ss)
ll
1 17156
2 17150
tt<-sqldf("select ll from ss")
(tt)
>
ll
1 NA
2 NA
> str(ss)
2012 May 12
1
Query regarding date as argument in functions - and about sqldf
Hi,
I have a query about sqldf, and dates in general. I couldnt find much on
the net or on the forums, hence I am here. Here is the issue:
I want to write a function that accepts 3 arguments: date1, date2 and a
dataframe, say 'df'. Within the function, I want to populate a temp
dataframe which essentially contains the output of the query "select * from
df where DATE between date1
2017 Aug 11
0
Package sqldf in R and dates manipulation
See FAQ #4 on the sqldf github home page.
On Fri, Aug 11, 2017 at 9:21 AM, Mangalani Peter Makananisa
<pmakananisa at sars.gov.za> wrote:
> Dear all,
>
> I recently read the book " R data preperation and manipulation using sqldf package" by Djoni Darmawikarta
> However, I have a problem with manipulation of dates using this package, I do not get the expected results.
2017 Aug 11
2
Package sqldf in R and dates manipulation
Dear all,
I recently read the book " R data preperation and manipulation using sqldf package" by Djoni Darmawikarta
However, I have a problem with manipulation of dates using this package, I do not get the expected results. Do I need to install some packages to be able to subset the data by dates in sqldf?
I am not getting Djoni Darmawikarta email address.
Please see the practice
2010 Nov 15
5
How to Read a Large CSV into a Database with R
Hi, I'm working in R 2.11.1 x64 on Windows x86_64-pc-mingw32. I'm trying to
insert a very large CSV file into a SQLite database. I'm pretty new to
working with databases in R, so I apologize if I'm overlooking something
obvious here.
I'm trying to work with the American Community Survey data, which is two
1.3GB csv files. I have enough RAM to read one of them into memory,
2012 Mar 21
1
Using extract function for dates in sqldf
I'm trying to use sqldf to query for the earliest date of a blood test when
patients have had multiple tests in a given year. My query looks like this:
test11 <- sqldf("select CHILD_ID, min(SAMP_DATE)
from lab
group by CHILD_ID
having extract (year from SAMP_DATE) = 2011")
SAMP_DATE has class "date." I get the error
2010 May 20
1
sqldf: issues with natural joins
Hello,
I'm having trouble discovering what's going wrong with my use of natural
joins via sqldf.
Following the instructions under 4i at http://code.google.com/p/sqldf/,
which discusses creating indices to speed joins, I have been only unreliably
able to get natural joins to work.
For example,
> Tid <- c('AES 01-01-02 10:58:00', 'AES 01-01-02 11:53:00', 'AES
2011 Mar 09
2
SQLDF - Submitting Queries with R Objects as Columns
Fellow R programmers,
I'd like to submit SQLDF statements with R objects as column names.
For example, I want to assign "X" to "var1" (var1<-"X") and then refer to
"var1" in the SQLDF statement. SQLDF needs to understand that when I
reference "var1", it should look for "X" in the dataframe.
This is necessary because my SQLDF
2008 Aug 28
3
drop unused levels in sqldf
Hi,
sqldf is a fantastic package, but when the SELECT procedure runs unused
levels remain in the output. I tried with the drop function, but without
success. Do you have any suggestions?
Thanx, Gianandrea
data(iris)
require(sqldf)
base<-sqldf("select * from iris where Species <> 'setosa'")
str(base) # Species with 3 levels!
--
View this message in context:
2007 Aug 01
1
New R package sqldf
sqldf is an R package for running SQL select
statements on one or more R data frames. It is
optimized for convenience making it useful
for ad hoc queries against R data frames.
Given an SQL select statement whose tables
are the names of R data frames it:
- sets up the database (by default it transparently
sets up an in memory SQLite database using RSQLite;
however, MySQL via RMySQL, can be
2007 Aug 01
1
New R package sqldf
sqldf is an R package for running SQL select
statements on one or more R data frames. It is
optimized for convenience making it useful
for ad hoc queries against R data frames.
Given an SQL select statement whose tables
are the names of R data frames it:
- sets up the database (by default it transparently
sets up an in memory SQLite database using RSQLite;
however, MySQL via RMySQL, can be
2008 Dec 14
1
error with sqldf v0-1.4
I'm getting an error message when using the new version of sqldf,
> library(sqldf)
> str(kdv)
'data.frame': 71 obs. of 3 variables:
$ dpss: num 0.117 0.144 0.164 0.166 0.165 ...
$ npdp: num 0.1264 0.0325 0.0109 0.0033 0.0055 ...
$ logk: num 1.12 1.29 1.41 1.41 1.42 ...
> test=sqldf("select * from kdv")
Error in get("fun", env = this, inherits =