Add two new articles #286
Merged
Add two new articles #286
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Contributor
cutterkom
commented
Oct 16, 2019
cutterkom
commented
- one article is the "history" part
- the other article is a draft for a general DBI introductory vignette
krlmlr
reviewed
Oct 24, 2019
|
|
||
| * MariaDB, using the R-package [RMariaDB](https://github.com/r-dbi/RMariaDB) | ||
| * Postgres, using and the R-package [RPostgres](https://github.com/r-dbi/RPostgres) | ||
| * SQLite, using and the R-package [RSQLite](https://github.com/r-dbi/RSQLite) |
| DBI offers a set of classes and methods that define what operations are possible and how they are performed: | ||
|
|
||
| * connect/disconnect to the DBMS | ||
| * create and execute statements in the DBMS |
| ```{r} | ||
| library(DBI) | ||
|
|
||
| con <- dbConnect(RSQLite::SQLite(), dbname = ":memory:") |
There was a problem hiding this comment.
What do we need to change to connect to Postgres or another database? What about ODBC?
| Basically, it is the result of the most generic SQL call `SELECT * FROM <name>`. | ||
|
|
||
| ```{r} | ||
| dbReadTable(con, "mtcars") |
There was a problem hiding this comment.
How do I access tables in a schema? (Difficult to show with SQLite.)
| ```{r} | ||
| res <- dbSendQuery(con, "SELECT * FROM mtcars WHERE cyl = 4") | ||
| while(!dbHasCompleted(res)){ | ||
| chunk <- dbFetch(res, n = 5) |
There was a problem hiding this comment.
Is this enough material for a specialized article?
| dbClearResult(res) | ||
| dbDisconnect(con) | ||
| ``` | ||
|
|
There was a problem hiding this comment.
- Parametrized queries?
- Transactions?
krlmlr
added a commit
that referenced
this pull request
Nov 22, 2019
|
Thanks! |
Sign up for free
to subscribe to this conversation on GitHub.
Already have an account?
Sign in.
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.