R6 class for managing DuckDB connections and pinning lazy database tables.
Wraps a pins::board_folder() with a cached connection object stored as
"cachedConnection" for automatic reconnection.
See also
conn() S4 generic for dbData objects
Methods
Method new()
Create a new dbProject object.
Method disconnect()
Close the current connection, if any.
Method reconnect()
Reconnect to the database in the project.
Method set_dbdir()
Update the project's cached DuckDB database path.
Usage
dbProject$set_dbdir(dbdir)
Arguments
dbdirPath to the DuckDB database file.
Details
Overwrites the "cachedConnection" pin with a connection that uses the
provided dbdir. Uses forced evaluation to avoid pins restoring a
connection that references an out-of-scope variable.
Method get_conn()
Retrieve the DBI connection from the project, reconnecting if necessary.
Returns
A DBIConnection object for direct database operations.
Method pin_write()
Write a lazy database tbl to the project.
Usage
dbProject$pin_write(x, name)
Arguments
xA dplyr::tbl object to be written to the board.
nameA character string specifying the name of the pin.
Returns
The materialized object (for dbMatrix/dbSpatial) pointing to permanent table,
or invisibly returns the dbProject object for other types.
Method pin_delete()
Delete a pin from the project.
Usage
dbProject$pin_delete(name, ...)
Arguments
nameA character string specifying the name of the pin to delete.
...Additional arguments passed to pins::pin_delete().
Returns
Invisibly returns the dbProject object for method chaining.
Method pin_read()
Read a pinned object from the project's board.
Arguments
nameA character string specifying the name of the pin.
Returns
The object stored in the specified pin.
Method restore()
Restore all pins from the board manifest.
Details
Reads the board manifest and restores the cached connection and all
pinned objects. The connection is restored internally, while other
pinned objects are returned as a named list for the user to assign.
Returns
A named list of restored pinned objects (excluding the connection).
Examples
\dontrun{
# Restore and assign objects
objs <- proj$restore()
my_matrix <- objs$my_matrix
my_spatial <- objs$my_spatial
}
Method dbRemoveTable()
Remove a table from the connected database
Usage
dbProject$dbRemoveTable(name)
Arguments
nameA character string specifying the name of the table to remove
Returns
Invisibly returns the dbProject object for method chaining
Method dbRemoveView()
Remove a view from the connected database
Usage
dbProject$dbRemoveView(name)
Arguments
nameA character string specifying the name of the table to remove
Returns
Invisibly returns the dbProject object for method chaining
Print summary information, including connection status, path, and board details.
Arguments
...Unused arguments (for consistency with generic print method)
Method is_connected()
Check if there is an active database connection.
Returns
A logical value indicating whether the project has an active connection.
Method clone()
The objects of this class are cloneable with this method.
Usage
dbProject$clone(deep = FALSE)
Arguments
deepWhether to make a deep clone.
Examples
## ------------------------------------------------
## Method `dbProject$restore`
## ------------------------------------------------
if (FALSE) { # \dontrun{
# Restore and assign objects
objs <- proj$restore()
my_matrix <- objs$my_matrix
my_spatial <- objs$my_spatial
} # }