Package 'RMariaDB' reference manual

Title:	Database Interface and MariaDB Driver
Description:	Implements a DBI-compliant interface to MariaDB (<https://mariadb.org/>) and MySQL (<https://www.mysql.com/>) databases.
Authors:	Kirill Müller [aut, cre] , Jeroen Ooms [aut] , David James [aut], Saikat DebRoy [aut], Hadley Wickham [aut], Jeffrey Horner [aut], R Consortium [fnd], RStudio [cph]
Maintainer:	Kirill Müller <[email protected]>
License:	MIT + file LICENSE
Version:	1.3.2.9011
Built:	2024-09-15 03:21:19 UTC
Source:	https://github.com/r-dbi/rmariadb

RMariaDB: Database Interface and MariaDB Driver

Description

Implements a DBI-compliant interface to MariaDB (https://mariadb.org/) and MySQL (https://www.mysql.com/) databases.

Author(s)

Maintainer: Kirill Müller [email protected] (ORCID)

Authors:

Jeroen Ooms (ORCID)
David James
Saikat DebRoy
Hadley Wickham
Jeffrey Horner

Other contributors:

R Consortium [funder]
RStudio [copyright holder]

Client flags

Description

Use for the client.flag argument to DBI::dbConnect(), multiple flags can be combined with + or bitwOr(). The flags are provided for completeness. To enforce SSL for the DB connection, add the flag CLIENT_SSL.

Examples

## Not run: 
library(DBI)
library(RMariaDB)
con1 <- dbConnect(MariaDB(), client.flag = CLIENT_COMPRESS)
con2 <- dbConnect(
  MariaDB(),
  client.flag = bitwOr(CLIENT_COMPRESS, CLIENT_SSL)
)

## End(Not run)

## Not run: 
library(DBI)
library(RMariaDB)
con1 <- dbConnect(MariaDB(), client.flag = CLIENT_COMPRESS)
con2 <- dbConnect(
  MariaDB(),
  client.flag = bitwOr(CLIENT_COMPRESS, CLIENT_SSL)
)

## End(Not run)

Determine the SQL Data Type of an S object

Description

This method is a straight-forward implementation of the corresponding generic function.

Usage

## S4 method for signature 'MariaDBConnection'
dbDataType(dbObj, obj, ...)

## S4 method for signature 'MariaDBDriver'
dbDataType(dbObj, obj, ...)
## S4 method for signature 'MariaDBConnection'
dbDataType(dbObj, obj, ...)

## S4 method for signature 'MariaDBDriver'
dbDataType(dbObj, obj, ...)

Arguments

`dbObj`	A MariaDBDriver or MariaDBConnection object.
`obj`	R/S-Plus object whose SQL type we want to determine.
`...`	any other parameters that individual methods may need.

Examples

dbDataType(RMariaDB::MariaDB(), "a")
dbDataType(RMariaDB::MariaDB(), 1:3)
dbDataType(RMariaDB::MariaDB(), 2.5)
dbDataType(RMariaDB::MariaDB(), "a")
dbDataType(RMariaDB::MariaDB(), 1:3)
dbDataType(RMariaDB::MariaDB(), 2.5)

Connect/disconnect to a MariaDB DBMS

Description

These methods are straight-forward implementations of the corresponding generic functions.

Usage

MariaDB()

## S4 method for signature 'MariaDBDriver'
dbConnect(
  drv,
  dbname = NULL,
  username = NULL,
  password = NULL,
  host = NULL,
  unix.socket = NULL,
  port = 0,
  client.flag = 0,
  group = "rs-dbi",
  default.file = NULL,
  ssl.key = NULL,
  ssl.cert = NULL,
  ssl.ca = NULL,
  ssl.capath = NULL,
  ssl.cipher = NULL,
  ...,
  groups = NULL,
  load_data_local_infile = FALSE,
  bigint = c("integer64", "integer", "numeric", "character"),
  timeout = 10,
  timezone = "+00:00",
  timezone_out = NULL,
  reconnect = FALSE,
  mysql = NULL
)
MariaDB()

## S4 method for signature 'MariaDBDriver'
dbConnect(
  drv,
  dbname = NULL,
  username = NULL,
  password = NULL,
  host = NULL,
  unix.socket = NULL,
  port = 0,
  client.flag = 0,
  group = "rs-dbi",
  default.file = NULL,
  ssl.key = NULL,
  ssl.cert = NULL,
  ssl.ca = NULL,
  ssl.capath = NULL,
  ssl.cipher = NULL,
  ...,
  groups = NULL,
  load_data_local_infile = FALSE,
  bigint = c("integer64", "integer", "numeric", "character"),
  timeout = 10,
  timezone = "+00:00",
  timezone_out = NULL,
  reconnect = FALSE,
  mysql = NULL
)

Arguments

`drv`	an object of class MariaDBDriver or MariaDBConnection.
`dbname`	string with the database name or NULL. If not NULL, the connection sets the default database to this value.
`username`, `password`	Username and password. If username omitted, defaults to the current user. If password is omitted, only users without a password can log in.
`host`	string identifying the host machine running the MariaDB server or NULL. If NULL or the string `"localhost"`, a connection to the local host is assumed.
`unix.socket`	(optional) string of the unix socket or named pipe.
`port`	(optional) integer of the TCP/IP default port.
`client.flag`	(optional) integer setting various MariaDB client flags, see Client-flags for details.
`group`	string identifying a section in the `default.file` to use for setting authentication parameters (see `MariaDB()`).
`default.file`	string of the filename with MariaDB client options, only relevant if `groups` is given. The default value depends on the operating system (see references), on Linux and OS X the files `⁠~/.my.cnf⁠` and `⁠~/.mylogin.cnf⁠` are used. Expanded with `normalizePath()`.
`ssl.key`	(optional) string of the filename of the SSL key file to use. Expanded with `normalizePath()`.
`ssl.cert`	(optional) string of the filename of the SSL certificate to use. Expanded with `normalizePath()`.
`ssl.ca`	(optional) string of the filename of an SSL certificate authority file to use. Expanded with `normalizePath()`.
`ssl.capath`	(optional) string of the path to a directory containing the trusted SSL CA certificates in PEM format. Expanded with `normalizePath()`.
`ssl.cipher`	(optional) string list of permitted ciphers to use for SSL encryption.
`...`	Unused, needed for compatibility with generic.
`groups`	deprecated, use `group` instead.
`load_data_local_infile`	Set to `TRUE` to use `⁠LOAD DATA LOCAL INFILE⁠` in `DBI::dbWriteTable()` and `DBI::dbAppendTable()` by default. This capability is disabled by default on the server side for recent versions of MySQL Server.
`bigint`	The R type that 64-bit integer types should be mapped to, default is bit64::integer64, which allows the full range of 64 bit integers.
`timeout`	Connection timeout, in seconds. Use `Inf` or a negative value for no timeout.
`timezone`	(optional) time zone for the connection, the default corresponds to UTC. Set this argument if your server or database is configured with a different time zone than UTC. Set to `NULL` to automatically determine the server time zone.
`timezone_out`	The time zone returned to R. The default is to use the value of the `timezone` argument, `"+00:00"` is converted to `"UTC"` If you want to display datetime values in the local timezone, set to `Sys.timezone()` or `""`. This setting does not change the time values returned, only their display.
`reconnect`	(experimental) Set to `TRUE` to use `MYSQL_OPT_RECONNECT` to enable automatic reconnection. This is experimental and could be dangerous if the connection is lost in the middle of a transaction.
`mysql`	Set to `TRUE`/`FALSE` to connect to a MySQL server or to a MariaDB server, respectively. The RMariaDB package supports both MariaDB and MySQL servers, but the SQL dialect and other details vary. The default is to assume MariaDB if the version is >= 10.0.0, and MySQL otherwise.

Time zones

MySQL and MariaDB support named time zones, they must be installed on the server. See https://dev.mysql.com/doc/mysql-g11n-excerpt/8.0/en/time-zone-support.html for more details. Without installation, time zone support is restricted to UTC offset, which cannot take into account DST offsets.

Secure passwords

Avoid storing passwords hard-coded in the code, use e.g. the keyring package to store and retrieve passwords in a secure way.

The MySQL client library (but not MariaDB) supports a .mylogin.cnf file that can be passed in the default.file argument. This file can contain an obfuscated password, which is not a secure way to store passwords but may be acceptable if the user is aware of the restrictions. The availability of this feature depends on the client library used for compiling the RMariaDB package. Windows and macOS binaries on CRAN are compiled against the MariaDB Connector/C client library which do not support this feature.

References

Configuration files: https://mariadb.com/kb/en/library/configuring-mariadb-with-mycnf/

Examples

if (mariadbHasDefault()) {
  # connect to a database and load some data
  con <- dbConnect(RMariaDB::MariaDB(), dbname = "test")
  dbWriteTable(con, "USArrests", datasets::USArrests, temporary = TRUE)

  # query
  rs <- dbSendQuery(con, "SELECT * FROM USArrests")
  d1 <- dbFetch(rs, n = 10)      # extract data in chunks of 10 rows
  dbHasCompleted(rs)
  d2 <- dbFetch(rs, n = -1)      # extract all remaining data
  dbHasCompleted(rs)
  dbClearResult(rs)
  dbListTables(con)

  # clean up
  dbDisconnect(con)
}
## Not run: 
# Connect to a MariaDB database running locally
con <- dbConnect(RMariaDB::MariaDB(), dbname = "mydb")
# Connect to a remote database with username and password
con <- dbConnect(RMariaDB::MariaDB(),
  host = "mydb.mycompany.com",
  user = "abc", password = "def"
)
# But instead of supplying the username and password in code, it's usually
# better to set up a group in your .my.cnf (usually located in your home
# directory). Then it's less likely you'll inadvertently share them.
con <- dbConnect(RMariaDB::MariaDB(), group = "test")

# To connect to a remote database and require the use of SSL
(and an example of using environment variables for your sensitive info)
con <- dbConnect(RMariaDB::MariaDB(),
  dbname = Sys.getenv('DB_NAME'),
  host = Sys.getenv('DB_HOST'),
  user = Sys.getenv('DB_USER'),
  password = Sys.getenv('DB_PASSWORD'),
  client.flag = CLIENT_SSL
)

# Always cleanup by disconnecting the database
dbDisconnect(con)

## End(Not run)

# All examples use the rs-dbi group by default.
if (mariadbHasDefault()) {
  con <- dbConnect(RMariaDB::MariaDB(), dbname = "test")
  con
  dbDisconnect(con)
}

if (mariadbHasDefault()) {
  # connect to a database and load some data
  con <- dbConnect(RMariaDB::MariaDB(), dbname = "test")
  dbWriteTable(con, "USArrests", datasets::USArrests, temporary = TRUE)

  # query
  rs <- dbSendQuery(con, "SELECT * FROM USArrests")
  d1 <- dbFetch(rs, n = 10)      # extract data in chunks of 10 rows
  dbHasCompleted(rs)
  d2 <- dbFetch(rs, n = -1)      # extract all remaining data
  dbHasCompleted(rs)
  dbClearResult(rs)
  dbListTables(con)

  # clean up
  dbDisconnect(con)
}
## Not run: 
# Connect to a MariaDB database running locally
con <- dbConnect(RMariaDB::MariaDB(), dbname = "mydb")
# Connect to a remote database with username and password
con <- dbConnect(RMariaDB::MariaDB(),
  host = "mydb.mycompany.com",
  user = "abc", password = "def"
)
# But instead of supplying the username and password in code, it's usually
# better to set up a group in your .my.cnf (usually located in your home
# directory). Then it's less likely you'll inadvertently share them.
con <- dbConnect(RMariaDB::MariaDB(), group = "test")

# To connect to a remote database and require the use of SSL
(and an example of using environment variables for your sensitive info)
con <- dbConnect(RMariaDB::MariaDB(),
  dbname = Sys.getenv('DB_NAME'),
  host = Sys.getenv('DB_HOST'),
  user = Sys.getenv('DB_USER'),
  password = Sys.getenv('DB_PASSWORD'),
  client.flag = CLIENT_SSL
)

# Always cleanup by disconnecting the database
dbDisconnect(con)

## End(Not run)

# All examples use the rs-dbi group by default.
if (mariadbHasDefault()) {
  con <- dbConnect(RMariaDB::MariaDB(), dbname = "test")
  con
  dbDisconnect(con)
}

Read and write MariaDB tables.

Description

These methods read or write entire tables from a MariaDB database.

Usage

## S4 method for signature 'MariaDBConnection'
dbAppendTable(conn, name, value, ..., row.names = NULL)

## S4 method for signature 'MariaDBConnection,character'
dbExistsTable(conn, name, ...)

## S4 method for signature 'MariaDBConnection'
dbListObjects(conn, prefix = NULL, ...)

## S4 method for signature 'MariaDBConnection'
dbListTables(conn, ...)

## S4 method for signature 'MariaDBConnection,character'
dbReadTable(conn, name, ..., row.names = FALSE, check.names = TRUE)

## S4 method for signature 'MariaDBConnection,character'
dbRemoveTable(conn, name, ..., temporary = FALSE, fail_if_missing = TRUE)

## S4 method for signature 'MariaDBConnection,character,character'
dbWriteTable(
  conn,
  name,
  value,
  field.types = NULL,
  overwrite = FALSE,
  append = FALSE,
  header = TRUE,
  row.names = FALSE,
  nrows = 50,
  sep = ",",
  eol = "\n",
  skip = 0,
  quote = "\"",
  temporary = FALSE,
  ...
)

## S4 method for signature 'MariaDBConnection,character,data.frame'
dbWriteTable(
  conn,
  name,
  value,
  field.types = NULL,
  row.names = FALSE,
  overwrite = FALSE,
  append = FALSE,
  ...,
  temporary = FALSE
)
## S4 method for signature 'MariaDBConnection'
dbAppendTable(conn, name, value, ..., row.names = NULL)

## S4 method for signature 'MariaDBConnection,character'
dbExistsTable(conn, name, ...)

## S4 method for signature 'MariaDBConnection'
dbListObjects(conn, prefix = NULL, ...)

## S4 method for signature 'MariaDBConnection'
dbListTables(conn, ...)

## S4 method for signature 'MariaDBConnection,character'
dbReadTable(conn, name, ..., row.names = FALSE, check.names = TRUE)

## S4 method for signature 'MariaDBConnection,character'
dbRemoveTable(conn, name, ..., temporary = FALSE, fail_if_missing = TRUE)

## S4 method for signature 'MariaDBConnection,character,character'
dbWriteTable(
  conn,
  name,
  value,
  field.types = NULL,
  overwrite = FALSE,
  append = FALSE,
  header = TRUE,
  row.names = FALSE,
  nrows = 50,
  sep = ",",
  eol = "\n",
  skip = 0,
  quote = "\"",
  temporary = FALSE,
  ...
)

## S4 method for signature 'MariaDBConnection,character,data.frame'
dbWriteTable(
  conn,
  name,
  value,
  field.types = NULL,
  row.names = FALSE,
  overwrite = FALSE,
  append = FALSE,
  ...,
  temporary = FALSE
)

Arguments

`conn`	a MariaDBConnection object, produced by `DBI::dbConnect()`
`name`	a character string specifying a table name.
`value`	A data frame.
`...`	Unused, needed for compatibility with generic.
`row.names`	Either `TRUE`, `FALSE`, `NA` or a string. If `TRUE`, always translate row names to a column called "row_names". If `FALSE`, never translate row names. If `NA`, translate rownames only if they're a character vector. A string is equivalent to `TRUE`, but allows you to override the default name. For backward compatibility, `NULL` is equivalent to `FALSE`.
`prefix`	A fully qualified path in the database's namespace, or `NULL`. This argument will be processed with `dbUnquoteIdentifier()`. If given the method will return all objects accessible through this prefix.
`check.names`	If `TRUE`, the default, column names will be converted to valid R identifiers.
`temporary`	If `TRUE`, creates a temporary table that expires when the connection is closed. For `dbRemoveTable()`, only temporary tables are considered if this argument is set to `TRUE`.
`fail_if_missing`	If `FALSE`, `dbRemoveTable()` succeeds if the table doesn't exist.
`field.types`	Optional, overrides default choices of field types, derived from the classes of the columns in the data frame.
`overwrite`	a logical specifying whether to overwrite an existing table or not. Its default is `FALSE`.
`append`	a logical specifying whether to append to an existing table in the DBMS. If appending, then the table (or temporary table) must exist, otherwise an error is reported. Its default is `FALSE`.
`header`	logical, does the input file have a header line? Default is the same heuristic used by `read.table()`, i.e., `TRUE` if the first line has one fewer column that the second line.
`nrows`	number of lines to rows to import using `read.table` from the input file to create the proper table definition. Default is 50.
`sep`	field separator character
`eol`	End-of-line separator
`skip`	number of lines to skip before reading data in the input file.
`quote`	the quote character used in the input file (defaults to `⁠\"⁠`.)

Details

When using load_data_local_infile = TRUE in DBI::dbConnect(), pass safe = FALSE to dbAppendTable() to avoid transactions. Because ⁠LOAD DATA INFILE⁠ is used internally, this means that rows violating primary key constraints are now silently ignored.

Value

A data.frame in the case of dbReadTable(); otherwise a logical indicating whether the operation was successful.

Note

The data.frame returned by dbReadTable() only has primitive data, e.g., it does not coerce character data to factors. Temporary tables are ignored for dbExistsTable() and dbListTables() due to limitations of the underlying C API. For this reason, a prior existence check is performed only before creating a regular persistent table; an attempt to create a temporary table with an already existing name will fail with a message from the database driver.

Examples

if (mariadbHasDefault()) {
  con <- dbConnect(RMariaDB::MariaDB(), dbname = "test")

  # By default, row names are written in a column to row_names, and
  # automatically read back into the row.names()
  dbWriteTable(con, "mtcars", mtcars[1:5, ], temporary = TRUE)
  dbReadTable(con, "mtcars")
  dbReadTable(con, "mtcars", row.names = FALSE)
}
if (mariadbHasDefault()) {
  con <- dbConnect(RMariaDB::MariaDB(), dbname = "test")

  # By default, row names are written in a column to row_names, and
  # automatically read back into the row.names()
  dbWriteTable(con, "mtcars", mtcars[1:5, ], temporary = TRUE)
  dbReadTable(con, "mtcars")
  dbReadTable(con, "mtcars", row.names = FALSE)
}

MariaDB Check for Compiled Versus Loaded Client Library Versions

Description

This function prints out the compiled and loaded client library versions.

Usage

mariadbClientLibraryVersions()
mariadbClientLibraryVersions()

Value

A named integer vector of length two, the first element representing the compiled library version and the second element representing the loaded client library version.

Examples

mariadbClientLibraryVersions()
mariadbClientLibraryVersions()

Check if default database is available.

Description

RMariaDB examples and tests connect to a database defined by the rs-dbi group in ⁠~/.my.cnf⁠. This function checks if that database is available, and if not, displays an informative message. mariadbDefault() works similarly but throws a testthat skip condition on failure, making it suitable for use in tests.

Usage

mariadbHasDefault()

mariadbDefault()
mariadbHasDefault()

mariadbDefault()

Examples

if (mariadbHasDefault()) {
  db <- dbConnect(RMariaDB::MariaDB(), dbname = "test")
  dbListTables(db)
  dbDisconnect(db)
}
if (mariadbHasDefault()) {
  db <- dbConnect(RMariaDB::MariaDB(), dbname = "test")
  dbListTables(db)
  dbDisconnect(db)
}

Execute a SQL statement on a database connection.

Description

To retrieve results a chunk at a time, use DBI::dbSendQuery(), DBI::dbFetch(), then DBI::dbClearResult(). Alternatively, if you want all the results (and they'll fit in memory) use DBI::dbGetQuery() which sends, fetches and clears for you. For data manipulation queries (i.e. queries that do not return data, such as UPDATE, DELETE, etc.), DBI::dbSendStatement() serves as a counterpart to DBI::dbSendQuery(), while DBI::dbExecute() corresponds to DBI::dbGetQuery().

Usage

## S4 method for signature 'MariaDBResult'
dbBind(res, params, ...)

## S4 method for signature 'MariaDBResult'
dbClearResult(res, ...)

## S4 method for signature 'MariaDBResult'
dbFetch(res, n = -1, ..., row.names = FALSE)

## S4 method for signature 'MariaDBResult'
dbGetStatement(res, ...)

## S4 method for signature 'MariaDBConnection,character'
dbSendQuery(conn, statement, params = NULL, ..., immediate = FALSE)

## S4 method for signature 'MariaDBConnection,character'
dbSendStatement(conn, statement, params = NULL, ..., immediate = FALSE)
## S4 method for signature 'MariaDBResult'
dbBind(res, params, ...)

## S4 method for signature 'MariaDBResult'
dbClearResult(res, ...)

## S4 method for signature 'MariaDBResult'
dbFetch(res, n = -1, ..., row.names = FALSE)

## S4 method for signature 'MariaDBResult'
dbGetStatement(res, ...)

## S4 method for signature 'MariaDBConnection,character'
dbSendQuery(conn, statement, params = NULL, ..., immediate = FALSE)

## S4 method for signature 'MariaDBConnection,character'
dbSendStatement(conn, statement, params = NULL, ..., immediate = FALSE)

Arguments

`res`	A MariaDBResult object.
`params`	A list of query parameters to be substituted into a parameterised query.
`...`	Unused. Needed for compatibility with generic.
`n`	Number of rows to retrieve. Use -1 to retrieve all rows.
`row.names`	Either `TRUE`, `FALSE`, `NA` or a string. If `TRUE`, always translate row names to a column called "row_names". If `FALSE`, never translate row names. If `NA`, translate rownames only if they're a character vector. A string is equivalent to `TRUE`, but allows you to override the default name. For backward compatibility, `NULL` is equivalent to `FALSE`.
`conn`	A MariaDBConnection object.
`statement`	A character vector of length one specifying the SQL statement that should be executed. Only a single SQL statement should be provided.
`immediate`	If TRUE, uses the `mysql_real_query()` API instead of `mysql_stmt_init()`. This allows passing multiple statements (with CLIENT_MULTI_STATEMENTS) and turns off the ability to pass parameters.

Examples

if (mariadbHasDefault()) {
  con <- dbConnect(RMariaDB::MariaDB(), dbname = "test")
  dbWriteTable(con, "arrests", datasets::USArrests, temporary = TRUE)

  # Run query to get results as dataframe
  dbGetQuery(con, "SELECT * FROM arrests limit 3")

  # Send query to pull requests in batches
  res <- dbSendQuery(con, "SELECT * FROM arrests")
  data <- dbFetch(res, n = 2)
  data
  dbHasCompleted(res)

  dbClearResult(res)
  dbDisconnect(con)
}
if (mariadbHasDefault()) {
  con <- dbConnect(RMariaDB::MariaDB(), dbname = "test")
  dbWriteTable(con, "arrests", datasets::USArrests, temporary = TRUE)

  # Run query to get results as dataframe
  dbGetQuery(con, "SELECT * FROM arrests limit 3")

  # Send query to pull requests in batches
  res <- dbSendQuery(con, "SELECT * FROM arrests")
  data <- dbFetch(res, n = 2)
  data
  dbHasCompleted(res)

  dbClearResult(res)
  dbDisconnect(con)
}

Database interface meta-data.

Description

See documentation of generics for more details.

Usage

## S4 method for signature 'MariaDBResult'
dbColumnInfo(res, ...)

## S4 method for signature 'MariaDBResult'
dbGetRowCount(res, ...)

## S4 method for signature 'MariaDBResult'
dbGetRowsAffected(res, ...)

## S4 method for signature 'MariaDBResult'
dbHasCompleted(res, ...)
## S4 method for signature 'MariaDBResult'
dbColumnInfo(res, ...)

## S4 method for signature 'MariaDBResult'
dbGetRowCount(res, ...)

## S4 method for signature 'MariaDBResult'
dbGetRowsAffected(res, ...)

## S4 method for signature 'MariaDBResult'
dbHasCompleted(res, ...)

Arguments

`res`	An object of class MariaDBResult
`...`	Ignored. Needed for compatibility with generic

Examples

if (mariadbHasDefault()) {
  con <- dbConnect(RMariaDB::MariaDB(), dbname = "test")
  dbWriteTable(con, "t1", datasets::USArrests, temporary = TRUE)

  rs <- dbSendQuery(con, "SELECT * FROM t1 WHERE UrbanPop >= 80")
  rs

  dbGetStatement(rs)
  dbHasCompleted(rs)
  dbColumnInfo(rs)

  dbFetch(rs)
  rs

  dbClearResult(rs)
  dbDisconnect(con)
}
if (mariadbHasDefault()) {
  con <- dbConnect(RMariaDB::MariaDB(), dbname = "test")
  dbWriteTable(con, "t1", datasets::USArrests, temporary = TRUE)

  rs <- dbSendQuery(con, "SELECT * FROM t1 WHERE UrbanPop >= 80")
  rs

  dbGetStatement(rs)
  dbHasCompleted(rs)
  dbColumnInfo(rs)

  dbFetch(rs)
  rs

  dbClearResult(rs)
  dbDisconnect(con)
}

DBMS Transaction Management

Description

Commits or roll backs the current transaction in an MariaDB connection. Note that in MariaDB DDL statements (e.g. ⁠CREATE TABLE⁠) cannot be rolled back.

Usage

## S4 method for signature 'MariaDBConnection'
dbBegin(conn, ...)

## S4 method for signature 'MariaDBConnection'
dbCommit(conn, ...)

## S4 method for signature 'MariaDBConnection'
dbRollback(conn, ...)
## S4 method for signature 'MariaDBConnection'
dbBegin(conn, ...)

## S4 method for signature 'MariaDBConnection'
dbCommit(conn, ...)

## S4 method for signature 'MariaDBConnection'
dbRollback(conn, ...)

Arguments

`conn`	a MariaDBConnection object, as produced by `DBI::dbConnect()`.
`...`	Unused.

Examples

if (mariadbHasDefault()) {
  con <- dbConnect(RMariaDB::MariaDB(), dbname = "test")
  df <- data.frame(id = 1:5)

  dbWriteTable(con, "df", df, temporary = TRUE)
  dbBegin(con)
  dbExecute(con, "UPDATE df SET id = id * 10")
  dbGetQuery(con, "SELECT id FROM df")
  dbRollback(con)

  dbGetQuery(con, "SELECT id FROM df")

  dbDisconnect(con)
}
if (mariadbHasDefault()) {
  con <- dbConnect(RMariaDB::MariaDB(), dbname = "test")
  df <- data.frame(id = 1:5)

  dbWriteTable(con, "df", df, temporary = TRUE)
  dbBegin(con)
  dbExecute(con, "UPDATE df SET id = id * 10")
  dbGetQuery(con, "SELECT id FROM df")
  dbRollback(con)

  dbGetQuery(con, "SELECT id FROM df")

  dbDisconnect(con)
}

Package 'RMariaDB'

Help Index

RMariaDB: Database Interface and MariaDB Driver

Description

Author(s)

See Also

Client flags

Description

See Also

Examples

Determine the SQL Data Type of an S object

Description

Usage

Arguments

Examples

Connect/disconnect to a MariaDB DBMS

Description

Usage

Arguments

Time zones

Secure passwords

References

Examples

Read and write MariaDB tables.

Description

Usage

Arguments

Details

Value

Note

Examples

MariaDB Check for Compiled Versus Loaded Client Library Versions

Description

Usage

Value

Examples

Check if default database is available.

Description

Usage

Examples

Execute a SQL statement on a database connection.

Description

Usage

Arguments

Examples

Database interface meta-data.

Description

Usage

Arguments

Examples

DBMS Transaction Management

Description

Usage

Arguments

Examples