Parameter settings to aid debugging

While developing an application that involves access to external data sources (and in particular when using ODBC) it is advisable to enable the output of error messages from the driver and possibly other debug information. The module mmodbc defines the following parameters to enable debug output and to retrieve information about the SQL statements that have been executed (for a complete list of the module parameters the reader is refered to the mmodbc documentation in the `Mosel Language Reference Manual'). To obtain the corresponding mmoci parameter names, replace the prefix SQL by OCI.

SQLverbose

Enable/disable mesasge printing by the ODBC driver.

SQLdebug

Enable/disable debug mode.

SQLrowcnt

Number of lines affected by the last SQL command.

SQLrowxfr

Number of lines transfered by the last SQL command.

SQLsuccess

Indicates whether the last SQL command succeeded.

SQLconnection

Identification number of the active connection to a database.

Parameters are set and retrieved with Mosel statements similar to the following:

 setparam("SQLdebug", true)
 writeln("Number of lines transfered: ", getparam("SQLrowxfr"))

With the odbc driver you may also use the `debug' option of the driver instead of the global setting:

 initializations to "mmodbc.odbc:debug;data.xls"
  A as "MyOutTable1"
 end-initializations 

or

 initializations to "mmodbc.odbc:data.xls"
  A as "debug;MyOutTable1"
 end-initializations 

In the first case, the setting applies to the whole initializations block, in the second case only to the specific statement (there may be any number of statements in a single block).

With the oci driver, a connection string including the `debug' option as global setting will look as follows:

 initializations to "mmoci.oci:debug;myusername/mypassword@dbname"
  A as "MyOutTable1"
 end-initializations