I/O drivers

In order to simplify access to ODBC enabled data sources, this module provides a driver designed to be used in initializations blocks for both reading and writing data.

Driver odbc

odbc:[debug;][noindex;][colsize=#;][bufsize=#;]DSN

The driver can only be used in `initializations' blocks. The Data Source Name to use has to be given in the opening part of the block. Before the DSN, the following options may be stated:

debug

to execute the block in debug mode (to display what SQL queries are produced). This option is ignored if the model is not compiled with debug information,

noindex

to indicate that only data (no indices) are transferred between the data source and Mosel. By default, the first columns of each table are interpreted as index values for the array to be transferred. This behaviour is changed by this option,

colsize=c

to set the size of a text column (default 64 characters),

bufsize=c

to set the size of the data buffer in kilobytes (default 4).

In the block, each label entry is understood as a table name optionally followed by a list of column names in brackets (e.g. "my_table(col1,col2)"). All columns are used if no list of names is specified. Note that, before the table name, one can add option noindex to indicate that for this particular entry indices are not used.

Example:

initializations from "mmodbc.odbc:auction.db3"
 NWeeks as "PARAMS(Weeks)"      ! Initialize `NWeeks' with column `Weeks'
                                ! of table `PARAMS'
 BPROF as "noindex;BPROFILE"    ! Initialize `BPROF' with table `BPROFILE'
                                ! all columns being data (no indices)
end-initializations