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I need to download a table from postgree to R, but filtered by part of an INT.
I have been trying:
library(RPostgreSQL)
con <- dbConnect(PostgreSQL(), user= "#####", dbname="######",password="#####"
,host="#####", port='######')
vetor_id <- c("83052407","10406587","12272377")
match_id <- dbGetQuery(con,paste("
SELECT *
FROM public.data2015
WHERE id IN ('", paste(vetor_id,collapse = "','"),"')
",sep = ""))
dbDisconnect(con)
I also tried CONTAINS but didn't work.WHERE Contains(id,", paste(vetor_id,collapse = " OR "),"')
id is INT and vetor_id is just part of the values. I mean,vector_id = 83052407 must find id = 83052407000132.
How can I use something like LIKE and put vetor_id% ?
Is this what you want?
WHERE id::text like ? || '%'
This converts the integer id to a string, and attempts to match it against the parameter. If id starts with the parameter, the condition is satisfied.
Note that this uses a legitimate query parameter (represented by the question mark): you should get used to parameterize your queries rather than concatenating variables in the query string: this is cleaner, more efficient and safer.
I have a table with multiple columns (colA, colB, colC) and I want to run a query against each of them and store the result so I can use them for comparison purposes later, for example this query to find the ratio of NULL and not NULL values in a column:
SELECT COUNT(*) - COUNT(column), COUNT(column) FROM table;
I have too many columns to do this manually, so I'm looking for a way for it to cycle through each column and store the result. Using a WHILE loop in t-sql doesn't seem to be suitable to this problem, and trying to use for loop with R doesn't work at all:
tableDataColumnName <- names(tableDataDataframe)
for (i in tableDataColumnName){
nullColumnNumber <- dbGetQuery(con, "SELECT COUNT (*) - COUNT(i), COUNT(i) FROM dbo.table;")
}
Is there a way to execute a query multiple times, once for each column in a table, without doing so manually?
You're trying to use a variable within a string (the i). To do this you should either use paste or paste0 from base or something like the glue package
## Base
tableDataColumnName <- names(tableDataDataframe)
for (i in tableDataColumnName){
nullColumnNumber <- dbGetQuery(con, paste0("SELECT COUNT (*) - COUNT(", i, "), COUNT(", i, ") FROM dbo.table;"))
}
## Glue
library(glue)
for (i in tableDataColumnName){
nullColumnNumber <- dbGetQuery(con, glue("SELECT COUNT (*) - COUNT({i}), COUNT({i}) FROM dbo.table;"))
However, you're also overwriting the result on each iteration of the loop. My solution for the whole problem would be something like the following:
library(glue)
tableDataColumnName <- names(tableDataDataframe)
nullColumnNumber <- numeric(length(tableDataColumnName))
for (i in seq_along(tableDataColumnName)){
nullColumnNumber[i] <- dbGetQuery(con, glue("SELECT COUNT (*) - COUNT({tableDataColumnName[i]}), COUNT({tableDataColumnName[i]}) FROM dbo.table;"))
}
I am wondering what approach should have been selected to perform action from title. I am using ODBC connection and what I get from first sql query are like 40-50 rows in one column. What I want is to put this output as a values in to search for.
How should i treat this? Like a array or separated variables? I still do not know R well so just need to know where to search for.
Regards
------more explanation below----
I have list of 40-50 numbers of 10 digits each, organized in a column.
I am trying to do this:
list <- c(my_input)
sql_in <- paste0(list, collapse="")
and characters are organized like this after this operations:
'c(1234567890, , 1234567890, 1234567890)'
and almost all looks fine and fit into my query besides additional c character at the beginning and missing apostrophes.I try to use gsub function but did not work in way I want.
You may likely do this in one SQL call using a subquery. Notice in the call below that the result of
SELECT n_gear
FROM Gear
WHERE n_gear IN (3,4)
Is passed to the WHERE clause of the primary query. This is perfectly valid and will allow your query to execute entirely in SQL without having to do any intermediate steps in R.
(I use sqldf for simplicity of illustration, but this should work through just about any ODBC connection)
library(sqldf)
Gear <- data.frame(n_gear = 1:5)
sqldf(
"SELECT mpg, qsec, gear, wt
FROM mtcars
WHERE gear IN (SELECT n_gear
FROM Gear
WHERE n_gear IN (3,4))"
)
Try something like this:
list<-c("try","this") #The output from your first query
sql_in<-paste0(list, collapse="','")
The Output
paste("select * from table where table.var in ",paste("('",sql_in,"')",sep=''))
[1] "select * from table where table.var in ('try','this')"
If yuo have space as first or last element of the string you can use this code:
`list<-c(" first element is a space","try","this","last element is a space ")` #The output from your first query
Find space at first or last character
first_space<-substr(list, start = 1, stop = 1)==" "
last_space<-substr(list, start = nchar(list), stop = nchar(list))==" "
Remove spaces
list[first_space]<-substr(list[first_space], start = 2, stop = nchar(list[first_space]))
list[last_space]<-substr(list[last_space], start = 1, stop = nchar(list[last_space])-1)
sql_in<-paste0(list, collapse="','")
Your output
paste0("select * from table where table.var in ",paste("('",sql_in,"')",sep=''))
"select * from table where table.var in ('first element is a space','try','this','last element is a space')"
I think You are expecting some thing like shown below code,
data <- dbGetQuery(con, "select column from yourfirsttable")
list <- paste(data$column, collapse="','")
result <- dbGetQuery(con, statement = sprintf("select * from yourresulttable where inv in ('%s')",list))
It's not entirely clear exactly what you're wanting to achieve here. For example, one use case just means you can do it all with a join. But I have cases where I don't know the values for the test without doing some computation. Then I do a separate query having created a query string thus:
> id <- 1:5
> paste0("SELECT * FROM table WHERE ID IN (", paste0(id, collapse = ","), ")")
[1] "SELECT * FROM table WHERE ID IN (1,2,3,4,5)"
I am new to SQL and i am trying to figure out how i can "select all" in WHERE clause.
Let me make it bit more clearer why i would like to achieve that:
I do have reactive SQL in my Shiny App. The user can filter at least three different variables in my SQL:
In this case user can choose Kunde (Customer), Abmessung (Diameter) and Date. I do have hard time to figure out when the user wants to filter only one/two variables and not three (the combinations of possibilities inside is huge, and writing SQL Query in if statement for each is quite a thing). So for example the user would like to have Kunde (Customer) filtered but all the Abmessung (Diameters) kept.
Here is a sample SQL Query which i have used:
select * from x.xy where kdname IN (",paste0("'",paste(input$kunde,
collapse="', '"),"'"),") and abmessung IN (",paste0("'",paste(input$abm,
collapse="', '"),"'"),") and dati_create between
to_date('",format(input$date[1], '%d.%m.%Y'),"','dd.mm.yyyy') and
to_date('",format(input$date[2], '%d.%m.%Y'),"','dd.mm.yyyy') + (86399/86400)
Is there a possibility in SQL to use some kind of "*" in WHERE clause?
Why not simply do it using if to each condition and than paste collapse it
( i think there isn t way to do what your want without "if\esle" or "case" or "nvl" or "decode" so you need to hardcode it)
like:
input=list("kunde"="a","abm"="b",date=c("2016-01-01","2016-02-01"))
#input=list("kunde"="","abm"="",date=c("","")) # for test
sql_main="select * from x.xy "
sql_cond=list()
sql_cond[1]= if(input$kunde==""){NULL}else{paste0("kdname IN ('",paste(input$kunde,collapse="','"),"')")}
sql_cond[2]= if(input$abm==""){NULL}else{paste0("abmessung IN ('",paste(input$abm,collapse="', '"),"')")}
sql_cond[3]= if(input$date[1]==""|input$date[2]==""){NULL}else{paste0("dati_create between to_date('",as.character(as.Date(input$date[1]),'%d.%m.%Y'),"','dd.mm.yyyy') and
to_date('",as.character(as.Date(input$date[2]),'%d.%m.%Y'),"','dd.mm.yyyy') + (86399/86400)")}
sql_cond=sql_cond[!sapply(sql_cond,is.null)]# needed to del NULL in list
sql_cond_all=paste(sql_cond,collapse =" and ")
sql=if(sql_cond_all!=""){paste(sql_main,"where",sql_cond_all)}else{sql_main}
sql
If you use RMySQL you can just paste together a chr string as query.
So you could do something like this:
condition <- character()
if(input$kdname != "") condition <- append(condition, paste0("kdname IN '", paste(input$kdname, collapse = "', '"), "'"))
if(input$abm != "") condition <- append(condition, paste0("abmessung IN '", paste(input$abm, collapse = "', '"), "'"))
query <- paste("SELECT * FROM x.xy WHERE", paste(condition, collapse = " AND "))
I am not familiar with shiny. However, I think you could achieve your goal by using oracle's decode function.
The where clause will look something like this (pseudo-code)
where
decode(input_variable,null,1,input_variable)=decode(input_variable,null,1,table_column)
and dati_create between
decode(input_date1,null,'1/1/1900',input_date1)
and decode(input_date2,null,'1/1/3000',input_date2)
and table_column2 in (
SELECT decode(inputvarable2,null, (select table_column2 from dual)
,TRIM(REGEXP_SUBSTR(temp, '[^,]+', 1, level)) )
FROM (SELECT inputvarable2 temp FROM DUAL)
CONNECT BY level <= REGEXP_COUNT(temp, '[^,]+')
)
Here I assume that when input variable is not given - it has null value. Also, as user input sample was not provided, I assume that user input for in clause is comma separated string. (e.g. 'a,b,c')
And thus, if input_variable is null then where becomes 1=1 (always true), otherwise it is input_variable=table_column. With dates it is a little bit more tricky - so I give very early date (1/1/1900), or very far away one (1/1/3000). The logic behind in clause, is to convert user input into collection from comma separated string and then use the same trick with decode.
Though this might not be the most efficient way to do this.
Also I see that you are concatenating user input directly into your sql statement. This is highly risky - as your code would be prone to sql injection attacks.
I find sub function very useful when constructing queries, try this:
myquery <- 'select * from x.xy where kdname IN "NAME" and abmessung IN "ABM" and dati_create between DATE1 and DATE2 + (86399/86400)'
date1 <- input$date[1];date1 <- sub("-",".",date1);date1 <- sub("-",".",date1)
date2 <- input$date[2];date2 <- sub("-",".",date2);date2 <- sub("-",".",date2)
myquery <- sub("DATE1",date1,myquery)
myquery <- sub("DATE2",date2,myquery)
myquery <- sub("NAME",input$kunde,myquery)
myquery <- sub("ABM",input$abm,myquery)
myquery <- noquote(myquery)
myquery
I have a Shiny app that has a checkbox group input. The user can select multiple inputs. I also have an ODBC connection linked to a database. The process would be that when a user selects items from the check box group, that user input would be part of a string in the sql query to filter the data.
UI.R (partial to show example)
checkboxGroupInput('Type', 'Type', c(
"AX"="AX",
"AY"="AY",
"AZ"="AZ",
"BGB"="BGB",
"BT"="BT",
"BX"="BX",
"BXT"="BXT",
"C"="C",
"CNT"="CNT")),
The column in the table where the "Type" information is in is called COMPONENT, so my sql query using RODBC is
data <- odbcConnect("database", uid="username", pwd="password")
query <- (SELECT ID, NAME, TYPE FROM COMPONENT WHERE TYPE LIKE Input$Type)
df <- odbcQuery(data, query)
The query line would not work, but I have no idea how to take multiple inputs and place them properly in the query. Also, there is an added level of complexity that I am not sure how to handle. The data in the database is alpha numeric, so instead of AX, it might be listed as AX14 or AX 71. Also, because there are some one letter types, using a wildcard seems a little difficult.
To answer your initial question regarding "multiple inputs in the query", I use concatenation to achieve this.
Using paste0(), I write something as follows:
type = "AX14"
myQuery <- paste0("Select variable1, variable2 from my_table where type like ",type)
myQuery
[1] "Select variable1, variable2 from my_table where type like AX14"
You can add little things like single quotes or wildcard operators as follows:
myQuery <- paste0("Select variable1, variable2 from my_table where type like '%",type,"%'")
myQuery
[1] "Select variable1, variable2 from my_table where type like '%AX14%'"
Then proceed with actually running the query:
df <- odbcQuery(data, myQuery)