"Rahul Thathoo" <[EMAIL PROTECTED]> writes: > Hi. > > I am trying to get data from mysql database using a couple of queries. > I do one query to find out the indexes. Then i need to use these > indexes in another query, but i keep getting errors. > > Here is something: > > numb <- dbSendQuery(con2, "select distinct(comparison) from table1") > > count <- fetch(numb, -1) > > my.matrix <- as.matrix(count)
You've selected one column, why is it a matrix? You index it as a vector, so I think you just want: count <- fetch(numb, -1)[[1]] fetch returns a data.frame which for the select you gave will have one column. Extracting the column gives you the vector. > rs <- dbSendQuery(con2, "select A.comparison,A.id, A.q_value, > B.q_value from table1 as A, table1 as B where A.comparison = > 'my.matrix[11481]' AND B.comparison = 250 AND A.id = B.id") As the other responder suggested, you need to create a string using paste. However, depending on how large length(count) is, you might be better off doing: where A.comparison IN ('1', '2', '3', ..., 'n') AND Which would be something like: "where A.comparison in (", paste("'", count, "'", sep="", collapse=","), ") ..." You might also see if mysql supports nested selects in which case you don't need two queries (from R) at all. + seth ______________________________________________ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.