在R中运行代码块(编织程序包) [英] Running Code Chunks in R (knitr package)

问题描述

我正在处理一个Markdown文件，该文件希望使用knitr包将某些脚本写入代码块中，这是我以前从未使用过的.

I'm working on a markdown file I was sent that wants some of the script to be written in code chunks using the knitr package, which I've never used before.

我遇到的问题是，将脚本放在大块中时似乎无法正常工作，但是在该上下文之外运行它们时就可以正常工作.

The problem I'm running into is that the scripts don't appear to be working when placed in the chunks, but work just fine when I run them outside of that context.

示例:

sqlite <- dbDriver("SQLite")
con <- dbConnect(sqlite,"db/sqlite/table.db")

那行得通.

```{r db_connect}
sqlite <- dbDriver("SQLite")
con <- dbConnect(sqlite,"db/sqlite/table.db")
```

这不起作用.这是错误的回溯:

This does not work. Here is the traceback on the error:

Error in rsqlite_connect(dbname, loadable.extensions, flags, vfs) : Could 
not connect to database: unable to open database file
8. stop(structure(list(message = "Could not connect to database:\nunable to open database file", call = rsqlite_connect(dbname, loadable.extensions, flags, vfs), cppstack = structure(list(file = "", line = -1L, stack = "C++ stack not available on this system"), .Names = c("file", ...
7. rsqlite_connect(dbname, loadable.extensions, flags, vfs)
6. initialize(value, ...)
5. initialize(value, ...)
4. new("SQLiteConnection", ptr = rsqlite_connect(dbname,loadable.extensions, flags, vfs), dbname = dbname, flags = flags, vfs = vfs, loadable.extensions = loadable.extensions, ref = new.env(parent = emptyenv()))
3. .local(drv, ...)
2. dbConnect(sqlite, "db/sqlite/table.db")
1. dbConnect(sqlite, "db/sqlite/table.db")

有人对如何解决此问题有任何建议吗?

Does anyone have any recommendations on how to troubleshoot this?

推荐答案

第二次测试

% 
\documentclass[a4paper]{article}
\title{test }
\begin{document}
<<db_create>>=
require("RSQLite")
sqlite <- dbDriver("SQLite")
db <- dbConnect(SQLite(), dbname="Test.sqlite")
dbSendQuery(conn = db,
    "CREATE TABLE School
               (SchID INTEGER,
        Location TEXT,
        Authority TEXT,
        SchSize TEXT)")
dbListTables(con)
dbSendQuery(conn = db,
    "INSERT INTO School
VALUES (1, 'urban', 'state', 'medium')")
dbSendQuery(conn = db,
    "INSERT INTO School
VALUES (2, 'urban', 'independent', 'large')")
dbSendQuery(conn = db,
    "INSERT INTO School
VALUES (3, 'rural', 'state', 'small')")
@

<<db_connect>>=

con <- dbConnect(RSQLite::SQLite(), "Test.sqlite")
dbListTables(con)
@
\end{document}

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