dbR6 class

Fields

where

(inherited from R6_data class) Environment storing data & enclosing environment for metadata

metadata

Environment storing object metadata

Methods

initialize
Initialize dbR6 object.

---Parameters---

• filename ":memory:" for to create an in-memory database, or a name for an on-disk database.

• overwrite The name of the output.

finalize
Finalize dbR6 object.


get_metadata
Get object metadata.


list_tables
List tables in database.


get_tables_number
Get number of tables.


colnames
Get colnames of a table.

---Parameters---

• what Name of table.

nrow
Get the number of rows of a table.

---Parameters---

• what Name of table.

ncol
Get the number of columns of a table.

---Parameters---

• what Name of table.

dim
Get dimension of a table.

---Parameters---

• what Name of table.

print
Print dbR6 object graphical interface.


get_table
Get a table.

---Parameters---

• what Name of the table

• from Row where start to read (index >= 1)

• to Row where fininish to read

send_query
Send an SQL query.

---Parameters---

• query Query to send

send_statement
Send an SQL statement.

---Parameters---

• statement Statement to send

add_table
Add a table to a dbR6 object.

---Parameters---

• new_name Name for the new table

• new_df Input table

• overwrite Overwrite if already exists? Default FALSE

• append Append content if already exists? Default FALSE

• row.names Row names present? Default FALSE

• fun Function to apply to the table before writing it

• ... Additional parameters passed to RSQLite::dbWriteTable.

remove_table
Remove a table.

---Parameters---

• what Name of table.

create_table_from
Add an empty table.

---Parameters---

• new_names Name of the new table.

• from Table to copy structure from.

• overwrite Overwrite table if exists?.

save
Save a dbR6 database on disk.

---Parameters---

• to Name of the new table.

clone_db
Clone a dbR6 object.

---Parameters---

• to Name of the new table.

sort
Sort a table.

---Parameters---

• what Name of the table to sort.

• column Column used to sort.

• ... Vector with other columns used to sort.

create_index
Create an index for a table.

---Parameters---

• what Name of the table to sort.

• column Column used to Create index.

• unique Create unique index? (Logical).

• ... Other aditional columns in a character vector to create the index.

drop_index
Drop an index from a table.

---Parameters---

• what Name of the index to drop.

get_indices
Get indices for a table.


transaction
Generate transaction with the tables.

---Parameters---

• ... Character vector with transactions to parse.

filter
Filter a table using the given conditions.

---Parameters---

• table Name of the table.

• conditions Logical conditions.

• r_commands R commands to be evaluated in the condition ('where' query) indicated witihin %rs& and %re% as in: %rs% my_command %re%

exist_table
Verify if a table exists (Logical).

---Parameters---

• what Name of the table.

statement_chunk
Executes a statement in chunks

---Parameters---

• what Statement.

• n Chunk size.

streamer
Apply a function for an imput data table using chunks, storing the output into a new table.

---Parameters---

• input Input table.

• output Output table.

• my_fun R function to apply.

• n Chunk size.

write_dataframe
Write an external dataframe into the database using chunks.

---Parameters---

• input Input table.

• output Output table.

• has_colnames Colnames present? (Logical).

• chunksize Chunk size.

• sep Character separating cell elements (default = " ").

• fun Function to apply to the chunk before writing it to the database.

• ... Additional parameters passed to read.table.

write_matrix
Write an external matrix into the database using chunks.

---Parameters---

• input Input table.

• output Output table.

• has_colnames colnames present? Default TRUE.

• has_rownames rownames present? Default TRUE.

• my_fun Function to apply to the chunk before writing it to the database.

• data_mode R mode of the input data ("integer", "logical", "character", "numerical").