Product package defines packages for various database products providing schema metadata information.
To unify queries across various vendor this library uses metadata.info.Kind
and corresponding metadata.sink, storing supper set information across all vendors.
Each kind requires fixed number of criteria parameters, for example to query table metadata information, catalog and schema is required.
Inspect metadata.info.Kind for more details.
To define metadata information, register Query, with product including min supported version,
actual SQL, and criteria parameters matching exactly defining kind.
Criteria allow dynamic SQL building depending on criterion value which can define the following:
name of the aliased column used in WHERE clause
empty string in case vendor does not support/ignore specific criteria (i.e catalog)
'?' in case SQL embedded placeholder that binds with query parameter
'%' in case SQL embed placeholder that needs be substituted while building SQL