Removing columns from CDM_SOURCE and using METADATA instead

[vojtechhuser]

New convention for METADATA table:

• record CDM version in METADATA table with METADATA.VALUE = 'CDM version' and METADATA.VALUE_AS_STRING = '5.3' (or other formal version of CDM)
  The table must contain exactly one row for 'CDM version'

Changes to existing tables:

• delete column CDM_VERSION from table CDM_SOURCE

This is because the CDM_SOURCE can have 2 or more rows and the version may differ.

[vojtechhuser]

The first post will be addited as Themis WG1 finalizes the discussion. WG1 adopted the issue on my proposal to come up with convenstions for CDM source.

relevant forum disucssion is here:
http://forums.ohdsi.org/t/cdm-source-table-usage-and-conventions/4015

[clairblacketer]

I like this idea, I also think it should be mandatory to save this value for every CDM instance

[clairblacketer]

I have added this convention to v6.0 with a slight modification. Since we have not agreed in the CDM wg to remove the 'cdm_version' field from the CDM_SOURCE table, I have not removed it from the DDL. I did, however, add a line that will automatically add the CDM version to the metadata table.

[clairblacketer]

added in v6.0