saveSQLite: Save R data frame to SQLite file. This function saves a data...

In D4TAlink.light: GDP - Workflow Management

Save R data frame to SQLite file. This function saves a data frame to an SQLite database file. It can create indices on specified columns for faster querying. The database file is stored in the task's binary directory.

Description

Save R data frame to SQLite file. This function saves a data frame to an SQLite database file. It can create indices on specified columns for faster querying. The database file is stored in the task's binary directory.

Usage

saveSQLite(
  object,
  task,
  type,
  subdir = NULL,
  dirCreate = TRUE,
  index = NULL,
  tableName = "data",
  overwrite = FALSE,
  append = FALSE,
  row.names = FALSE
)

Arguments

object	data.frame to serialize.
task	Object of class D4TAlinkTask, as created by initTask.
type	Filename type. If the type is an array, the cocatenation of the elements is used with separator"-". Filenames have the form [task name]_[type].[ext]
subdir	(optional) Subdirectory.
dirCreate	Logical, if TRUE (by default) the directory is created.
index	character vector of column names to create indices on.
tableName	name of the table in the SQLite database.
overwrite	if TRUE, overwrite existing table.
append	if TRUE, append to existing table.
row.names	if TRUE, save row names as a column.

Value

The file name invisibly.

Examples

## Not run: 
task <- loadTask("myproject","mypackage","mytask")
# create a sample data frame
df <- data.frame(a = 1:5, b = letters[1:5])
# save it to SQLite
fn <- saveSQLite(df, task, "testdb",tableName="table1",
                 index = c("a"))
# read it back
df_loaded <- readSQLite(task,"testdb",tableName="table1")
# print the loaded data frame
print(df_loaded)
# add second data frame
df2 <- data.frame(a = 6:10, b = letters[6:10])
saveSQLite(df2, task,"testdb",tableName="table2")
# query the data
query_result <- querySQLite("SELECT * FROM table2 WHERE a > 8",
                            task,"testdb")
print(query_result)                           
#' # append to the first table
saveSQLite(df2, task,"testdb",tableName="table1",append=TRUE)
# read the updated table
df_loaded <- readSQLite(task,"testdb",tableName="table1")
# print the updated data frame
print(df_loaded)
# cleanup
unlink(fn)

## End(Not run) 

D4TAlink.light documentation built on Sept. 11, 2025, 1:07 a.m.