Pass R Variable to Rodbc'S Sqlquery

Pass R variable to RODBC's sqlQuery?

Build the string you intend to pass. So instead of

example <- sqlQuery(myDB,"SELECT * FROM dbo.my_table_fn (x)")

do

example <- sqlQuery(myDB, paste("SELECT * FROM dbo.my_table_fn (", 
                                x, ")", sep=""))

which will fill in the value of x.

Pass R variable to RODBC's sqlQuery with multiple entries?

Look into the collapse argument in the paste() documentation. Try replacing b with paste(b, collapse = ", "), as shown below.

Edit As Joshua points out, sqlQuery returns a data.frame, not a vector. So, instead of paste(b, collapse = ", "), you could use paste(b[[1]], collapse = ", ").

library(RODBC)
channel <- odbcConnect("test")
b <- sqlQuery(channel,
  "select top 1 Noinscr
   FROM table
   where PrixVente > 100
   order by datevente desc")

sqlQuery(channel,
   ## note paste(b[[1]], collapse = ", ") in line below
   paste("insert into TestTable (UniqueID) Values (", paste(b[[1]], collapse = ", "),")", sep = "")

Parameterize SQL Queries using R RODBC

You can create a input variable at the start and pass it to your query.
For example:

# Change your FY here
input_FY <- 2016

dbhandle <- odbcDriverConnect('driver={SQL Server};server=SQLSERVER;database=MYDATABASE;trusted_connection=true')

degrees <- sqlQuery(dbhandle, paste0("
select Inst, ID, DegreeDate, Degree 
from DEGREE 
where FY = ('", input_FY, "') 
group by Inst, ID, DegreeDate, Degree 
order by Inst, ID, DegreeDate, Degree"), 
as.is=TRUE)

So for any complicated queries you can still pass the same input_FY variable or any other variable that you have declared at the start of code for a quick/easy update.

Run SQL script from R with variables defined in R

There are several options, but my preferred is "bound parameters".

If, for instance, your 'Query.sql' looks something like

select ...
from MyTable
where CreatedDateTime > ?

The ? is a place-holder for a binding.

Then you can do

con <- dbConnect(...) # from DBI
df = dbGetQuery(con, statement = read_file('Query.sql'), params = list(dt))

With more parameters, add more ?s and more objects to the list, as in

qry <- "select ... where a > ? and b < ?"
newdat <- dbGetQuery(con, qry, params = list(var1, var2))

If you need a SQL IN clause, it gets a little dicey, since it doesn't bind things precisely like we want.

candidate_values <- c(2020, 1997, 1996, 1901)
qry <- paste("select ... where a > ? and b in (", paste(rep("?", length(candidate_values)), collapse=","), ")")
qry
# [1] "select ... where a > ? and b in ( ?,?,?,? )"
df <- dbGetQuery(con, qry, params = c(list(avar), as.list(candidate_values)))

R RODBC putting list of numbers into an IN() statement

You're not pasteing your query together correctly.

If you run the paste statement in isolation, you'll see that you get a vector of length 5000, so sqlQuery is only executing the first one of those, corresponding to the first element in samRowNum.

What you want to do is something more like this:

paste("select * FROM db where row_id in (", 
    paste(sampRowNum,collapse = ","),")", sep="")

Just as an added note (and since I've had to do stuff like this a lot...) constructing sql queries with an IN clause with strings is a bit more of a nuisance, since you have to tack on all the single quotes:

vec <- letters[1:5]

paste("SELECT * FROM db WHERE col IN ('",
    paste(vec,collapse = "','"),"')",sep = "")

[1] "SELECT * FROM db WHERE col IN ('a','b','c','d','e')"

If you do this a lot, you'll end up writing a little function that does that pasting of character vectors for you.

As always, this kind of SQL string manipulation is Not Good if you are dealing with user inputs (e.g. in a web app), due to SQL injection attacks. In my particular situation this isn't much of a concern, but in general people will prefer parametrized queries if you don't have much control over the input values.

Pass R Vector to Sql query

The new dbplyr package has the best answer for this. It allows any R object to be used, and automatically converts it to SQL

https://db.rstudio.com/dplyr/

How to pass function parameters in sql query in R?

You could try with paste:

func <- function(x){
  sqlQuery(dbhandle, paste('select attr from myTable where cond =', x))
}

RODBC using EXEC @variable query

Essentially, you are building a dynamic query in TSQL using procedural semantics. But R is a procedural language. Hence, consider looping through databases to build concatenated data frame (counterpart of UNION).

library(RODBC) 

sql <- "select a.colA, b.colB, c.colC 
        from dbo.tableA as a 
        inner join dbo.tableB as b on b.x = a.x 
        inner join dbo.tableC as c on c.y = b.y 
        where col1 is not null"

get_db_data <- function(db) {
     # DYNAMICAL DATABASE CONNECTION
     conn <- odbcDriverConnect(paste0("Driver={SQL Server};",
                                      "Server=myserver;Database=", db,
                                      ";Trusted_connection=Yes"))

     df <- sqlQuery(conn, sql)

     odbcClose(conn)

     return(df)
}

# BUILD LIST OF DFs FROM DIFFERENT DBs
df_list <- lapply(c("proj1", "proj2", "proj3"), get_db_data)

# EQUIVALENT TO UNION QUERY
final_df <- unique(do.call(rbind, df_list))

RODBC command 'sqlQuery' has problems with table variables in t-SQL

Try toggling NOCOUNT as below:

old_qry <- "
DECLARE @tbl_IDs TABLE 
(
    Country nvarchar(30),
    CID nvarchar(5),
    PriceID int,
    WindID int
)

INSERT INTO @tbl_IDs
VALUES 
    ('Germany', 'DE', 112000001, 256000002);

SELECT * FROM @tbl_Ids
"
##
new_qry <- "
SET NOCOUNT ON;
DECLARE @tbl_IDs TABLE 
(
    Country nvarchar(30),
    CID nvarchar(5),
    PriceID int,
    WindID int
);

INSERT INTO @tbl_IDs
VALUES 
    ('Germany', 'DE', 112000001, 256000002);
SET NOCOUNT OFF;
SELECT * FROM @tbl_Ids
"

---

R> sqlQuery(tcon, gsub("\\n", " ", old_qry))
#character(0)
R> sqlQuery(tcon, gsub("\\n", " ", new_qry))
#  Country CID   PriceID    WindID
#1 Germany  DE 112000001 256000002

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Basically you want to SET NOCOUNT ON at the beginning of your code, and SET NOCOUNT OFF just before the final SELECT statement.

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