mysqlSupport             package:RMySQL             R Documentation

_S_u_p_p_o_r_t _F_u_n_c_t_i_o_n_s

_D_e_s_c_r_i_p_t_i_o_n:

     These functions are the workhorse behind the RMySQL package, but
     users need not invoke these directly.  For details see 'MySQL'.

_U_s_a_g_e:

        ## MySQLDriver-related
        mysqlInitDriver(max.con=16, fetch.default.rec = 500, force.reload=FALSE)
        mysqlDriverInfo(obj, what, ...)
        mysqlDescribeDriver(obj, verbose = FALSE, ...)
        mysqlCloseDriver(drv, ...)

        ## MySQLConnection-related
        mysqlNewConnection(drv, dbname, username, password, host, unix.socket,
              port, client.flag, groups)
        mysqlCloneConnection(con, ...)
        mysqlConnectionInfo(obj, what, ...)
        mysqlDescribeConnection(obj, verbose = FALSE, ...)
        mysqlCloseConnection(con, ...)

        ## MySQLResult-related
        mysqlExecStatement(con, statement)
        mysqlFetch(res, n=0, ...)
        mysqlQuickSQL(con, statement)
        mysqlResultInfo(obj, what, ...)
        mysqlDescribeResult(obj, verbose = FALSE, ...)
        mysqlCloseResult(res, ...)
        mysqlDescribeFields(res, ...)

        ## data mappings, convenience functions, and extensions
        mysqlDataType(obj, ...)
        mysqlReadTable(con, name, row.names = "row.names", check.names = TRUE, ...)
        mysqlWriteTable(con, name, value, field.types, row.names = TRUE, 
           overwrite=FALSE, append=FALSE, ..., allow.keywords = FALSE)

_A_r_g_u_m_e_n_t_s:

 max.con: positive integer specifying maximum number of open
          connections. The current default of 10 is hardcoded in the C
          code. 

fetch.default.rec: default number of rows to fetch (move to R/S-Plus). 
          This default is used in 'mysqlFetch'.  The default is 500. 

force.reload: logical indicating whether to re-initialize the driver. 
          This may be useful if you want to change the defaults (e.g.,
          'fetch.default.rec'). Note that the driver is a singleton
          (subsequent inits just returned the previously initialized
          driver, thus this argument). 

     obj: any of the MySQL DBI objects (e.g., 'MySQLConnection',
          'MySQLResult'). 

    what: character vector of metadata to extract, e.g., "version",
          "statement", "isSelect". 

 verbose: logical controlling how much information to display. Defaults
          to 'FALSE'. 

     drv: an 'MySQLDriver' object as produced by 'mysqlInitDriver'. 

     con: an 'MySQLConnection' object as produced by
          'mysqlNewConnection' and 'mysqlCloneConnection'. 

     res: an 'MySQLResult' object as produced by by
          'mysqlExecStatement'. 

username: a character string with the MySQL's user name.   

password: character string with the MySQL's password. 

  groups: character vector with one or more MySQL group names.  For
          details see 'MySQL'. 

  dbname: character string with the MySQL database name. 

    host: character string with the name (or IP address) of the machine
          hosting the database. Default is '""', which is interpreted
          as 'localhost' by the MySQL's API. 

unix.socket: (optional) character string with a filename for the socket
          file name.  Consult the MySQL documentation for details. 

    port: (optional) positive integer specifying the TCP port number
          that the MySQL server is listening to.  Consult the MySQL
          documentation  for details. 

client.flag: (optional) integer setting flags for the client.  Consult
          the MySQL documentation for details. 

   force: logical indicating whether to close a connection that has
          open result sets.  The default is 'FALSE'. 

statement: character string holding one (and only one) SQL statement. 

       n: number of rows to fetch from the given result set. A value of
          -1 indicates to retrieve all the rows.  The default of 0
          specifies to extract whatever the 'fetch.default.rec' was
          specified during driver initialization 'mysqlInit'. 

    name: character vector of names (table names, fields, keywords). 

   value: a data.frame. 

field.types: a list specifying the mapping from R/S-Plus fields in the
          data.frame 'value' to SQL data types.  The default is
          'sapply(value,SQLDataType)', see 'MySQLSQLType'. 

row.names: a logical specifying whether to prepend the 'value'
          data.frame  row names or not.  The default is 'TRUE'. 

check.names: a logical specifying whether to convert DBMS field names
          into legal S names. Default is 'TRUE'. 

overwrite: logical indicating whether to replace the table 'name' with
          the contents of the data.frame 'value'. The defauls is
          'FALSE'. 

  append: logical indicating whether to append 'value' to the existing
          table 'name'. 

allow.keywords: logical indicating whether column names that happen to
          be MySQL keywords be used as column names in the resulting
          relation (table) being written.  Defaults to 'FALSE', forcing
          'mysqlWriteTable' to modify column names to make them legal
          MySQL identifiers. 

     ...: placeholder for future use. 

_V_a_l_u_e:

     'mysqlInitDriver' returns an 'MySQLDriver' object.

     'mysqlDriverInfo' returns a list of name-value metadata pairs.

     'mysqlDescribeDriver' returns 'NULL' (displays the object's 
     metadata).

     'mysqlCloseDriver' returns a logical indicating whether the 
     operation succeeded or not.

     'mysqlNewConnection' returns an 'MySQLConnection' object.

     'mysqlCloneConnection' returns an 'MySQLConnection' object.

     'mysqlConnectionInfo'returns a list of name-value metadata pairs.

     'mysqlDescribeConnection' returns 'NULL' (displays the  object's
     metadata).

     'mysqlCloseConnection' returns a logical indicating whether the 
     operation succeeded or not.

     'mysqlExecStatement' returns an 'MySQLResult' object.

     'mysqlFetch' returns a data.frame.

     'mysqlQuickSQL' returns either a data.frame if the 'statement' is
     a 'select'-like or NULL otherwise.

     'mysqlDescribeResult' returns 'NULL' (displays the object's 
     metadata).

     'mysqlCloseResult' returns a logical indicating whether the 
     operation succeeded or not.

     'mysqlDescribeFields' returns a data.frame with one row per field
     with columns 'name', 'Sclass', 'type', 'len',  'precision',
     'scale', and 'nullOK' which fully describe each field in a result
     set.  Except for 'Sclass' (which shows the mapping of the field
     type into an R/S-Plus class) all the information pertains to
     MySQL's data storage attributes.

     'mysqlReadTable'  returns a data.frame with the contents of the
     DBMS table.

     'mysqlWriteTable'  returns a logical indicating whether the 
     operation succeeded or not.

     'mysqlDataType' retuns a character string with the closest

     'mysqlResultInfo' returns a list of name-value metadata pairs.

_C_o_n_s_t_a_n_t_s:

     '.MySQLPkgName' (currently '"RMySQL"'), '.MySQLPkgVersion' (the R
     package version), '.MySQLPkgRCS' (the RCS revision),
     '.MySQL.NA.string' (character that MySQL uses to  denote 'NULL' on
     input), '.MySQLSQLKeywords' (a lot!) '.conflicts.OK'.

