Requesting a JSON sub-field (e.g. jsonvalue->'product'->>'cost') that has
no matching bun scanonly field on the model made the whole read fail with
"bun: ModelX does not have column Y", since bun scans SELECT results
straight into the typed model struct.
Add reflection.HasColumn to check whether the model can actually receive
a given column (including scanonly fields, walking embedded structs), and
gate the JSON select-column expression on it in ApplySelectColumns
(shared by websocketspec/mqttspec) and the resolvespec/restheadspec
handlers. When there's no scan target, drop just that column with a
warning instead of erroring the whole request.
reflect.Type.Kind() on spectypes.SqlNull[T] wrappers (SqlInt16/32/64,
SqlFloat64, SqlBool, SqlString, and embedders like SqlTimeStamp) always
reports reflect.Struct, never the wrapped T. ValidateAndAdjustFilterForColumnType
treated those as "complex" columns and forced CAST(col AS TEXT) on eq/gt/lt
filters, e.g. CAST(atdetail.rid_parent AS TEXT) = '90446096', which can't
use the index on rid_parent.
Add spectypes.UnwrapKind to see through SqlNull wrappers to the underlying
Kind, and use it in GetColumnTypeFromModel so numeric/string SqlNull columns
are recognized correctly and compared natively.
Also stop unconditionally casting to TEXT for LIKE/ILIKE and add
reflection.IsCitextColumn: citext columns are already case-insensitive, so
casting them to TEXT flips to case-sensitive matching and defeats a citext
index.
* Implement BuildJSONToDBColumnMap for translating JSON keys to DB column names
* Enhance GetColumnName to extract column names with priority
* Update filterValidFields to utilize new mapping for improved data handling
* Fix TestToSnakeCase expected values for consistency
Hein