rodbc date filter

Question

I have been trying to set a query to a MS SQL database through RODBC. Unfortunately I cannot set appropriate date filters. I tried typing date in quotes and single quotes, DATE function, brackets and it doesn't want to work.

Here is the code:

    dbquery <- sqlQuery(dbhandle, 'SELECT ST03001, ST03003, ST03007, ST03015, ST03012, ST03020, ST03021, ST03022 
    FROM deh_10.dbo.ST031000 ST031000 
    WHERE (ST03015>'2013-01-01')')

I usually get this error message:

    "dbquery <- sqlQuery(dbhandle, 'SELECT ST03001, ST03003, ST03007, ST03015, ST03012,
     ST03020, ST03021, ST03022 FROM deh_10.dbo.ST031000 ST031000 WHERE
     (ST03015>DATE('2013"

After the date filter I have several other filters separated from each other by OR (excluded from the example).

Answer 1

It is better to construct your sql query, using paste, specially when you deal with dates. here I convert the dates to numeric, but it is optionally( it depends with the data base, I think that MS SQL convert character to dates automatically). I create my query using paste and sep ='\n':

For example :

query <- paste(
  'SELECT ST03001, ST03003, ST03007, ST03015, ST03012, ST03020, ST03021, ST03022 ',
  'FROM ST031000',
  paste("WHERE ST03015 >" , as.numeric(as.Date('2013-05-01')),sep=''),
  sep='\n')

Then using cat:

cat(query)
SELECT ST03001, ST03003, ST03007, ST03015, ST03012, ST03020, ST03021, ST03022 
FROM ST031000
WHERE ST03015 >15826

You can also do this (no need to convert to a numeric)

query <- paste(
+   'SELECT ST03001, ST03003, ST03007, ST03015, ST03012, ST03020, ST03021, ST03022 ',
+   'FROM ST031000',
+   paste("WHERE ST03015 >'" , as.Date('2013-05-01'),"'",sep=''),
+   sep='\n')

> cat(query)
SELECT ST03001, ST03003, ST03007, ST03015, ST03012, ST03020, ST03021, ST03022 
FROM ST031000
WHERE ST03015 >'2013-05-01'

Here an example using sqldf package. I create some data:

values <- as.data.frame(matrix(sample(1:100,8*6*3,rep=T),ncol=8))
colnames(values) <- c('ST03001', 'ST03003', 'ST03007', 'ST03015', 'ST03012', 'ST03020', 'ST03021', 'ST03022') 
values$ST03015 = seq(as.Date("2012/1/1"), as.Date("2013/06/1"), length.out= nrow(values))

Then:

sqldf(query <- paste(
  'SELECT ST03001, ST03003, ST03007, ST03015, ST03012, ST03020, ST03021, ST03022 ',
  'FROM ST031000',
  paste("WHERE ST03015 >" , as.numeric(as.Date('2013-05-01')),sep=''),
  sep='\n'))

     ST03001 ST03003 ST03007    ST03015 ST03012 ST03020 ST03021 ST03022
1      73      74      58 2013-05-01      82      85      88      58
2       8      63      71 2013-06-01      37      76      15      44