getSymbols.MySQL: Retrieve Data from MySQL Database

Description Usage Arguments Details Value Note Author(s) References See Also Examples

Description

Fetch data from MySQL database. As with other methods extending the getSymbols function, this should NOT be called directly. Its documentation is meant to highlight the formal arguments, as well as provide a reference for further user contributed data tools.

Usage

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getSymbols.MySQL(Symbols,
                 env, 
                 return.class = 'xts',
                 db.fields = c("date", "o", "h", "l", "c", "v", "a"), 
                 field.names = NULL,
                 user = NULL, 
                 password = NULL, 
                 dbname = NULL, 
                 host = "localhost", 
                 port = 3306, 
                 ...)

Arguments

Symbols

a character vector specifying the names of each symbol to be loaded

env

where to create objects. (.GlobalEnv)

return.class

desired class of returned object. Can be xts, zoo, data.frame, ts, or its. (zoo)

db.fields

character vector indicating names of fields to retrieve

field.names

names to assign to returned columns

user

username to access database

password

password to access database

dbname

database name

host

database host

port

database port

...

currently not used

Details

Meant to be called internally by getSymbols (see also)

One of a few currently defined methods for loading data for use with quantmod. Its use requires the packages DBI and MySQL, along with a running MySQL database with tables corresponding to the Symbol name.

The purpose of this abstraction is to make transparent the ‘source’ of the data, allowing instead the user to concentrate on the data itself.

Value

A call to getSymbols.MySQL will load into the specified environment one object for each Symbol specified, with class defined by return.class.

Note

The default configuration needs a table named for the Symbol specified (e.g. MSFT), with column names date,o,h,l,c,v,a. For table layout changes it is best to use setDefaults(getSymbols.MySQL,...) with the new db.fields values specified.

Author(s)

Jeffrey A. Ryan

References

MySQL AB http://www.mysql.com

David A. James and Saikat DebRoy (2006). R Interface to the MySQL databse. www.omegahat.org

R-SIG-DB. DBI: R Database Interface

See Also

getSymbols, setSymbolLookup

Examples

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## Not run: 
# All 3 getSymbols calls return the same
# MSFT to the global environment
# The last example is what NOT to do!

setDefaults(getSymbols.MySQL,user='jdoe',password='secret',
            dbname='tradedata')

## Method #1
getSymbols('MSFT',src='MySQL')


## Method #2
setDefaults(getSymbols,src='MySQL')
  # OR
setSymbolLookup(MSFT='MySQL')

getSymbols('MSFT')

#########################################
##  NOT RECOMMENDED!!!
#########################################
## Method #3
getSymbols.MySQL('MSFT',env=globalenv())

## End(Not run)

quantmod documentation built on May 2, 2019, 5:48 p.m.