schemawatch: Ignore hidden Oracle Database columns

This change updates the column inspection query to also consider the
HIDDEN_COLUMN value when deciding which columns to ignore.

internal/target/schemawatch/coldata.go

@@ -245,6 +245,7 @@ WITH atc AS (
     ELSE DATA_TYPE
   END DATA_TYPE,
   DATA_DEFAULT,
+  HIDDEN_COLUMN,
   VIRTUAL_COLUMN FROM ALL_TAB_COLS
 ),
      pk_cols  AS (SELECT OWNER, TABLE_NAME, CONSTRAINT_NAME FROM ALL_CONSTRAINTS WHERE CONSTRAINT_TYPE='P'),
@@ -254,7 +255,8 @@ SELECT /*+  gather_plan_statistics */
        COALESCE(IS_PK, 'f'),
        atc.DATA_TYPE,
        atc.DATA_DEFAULT,
-       CASE WHEN atc.VIRTUAL_COLUMN = 'YES' THEN 't' ELSE 'f' END
+       CASE WHEN (atc.HIDDEN_COLUMN = 'YES' OR atc.VIRTUAL_COLUMN = 'YES')
+            THEN 't' ELSE 'f' END
 FROM atc
 LEFT JOIN pk_cols  USING (OWNER, TABLE_NAME)
 LEFT JOIN acc USING (OWNER, TABLE_NAME, COLUMN_NAME, CONSTRAINT_NAME)

internal/target/schemawatch/coldata_test.go

@@ -306,6 +306,18 @@ func TestGetColumns(t *testing.T) {
 				"d", "VARCHAR2(1 CHAR)",
 			),
 		},
+		// Verify that hidden columns are ignored.
+		{
+			products:    []types.Product{types.ProductOracle},
+			tableSchema: "a INT PRIMARY KEY, b VARCHAR2(1 CHAR) DEFAULT 'n' NULL, c INT INVISIBLE",
+			primaryKeys: []string{"a"},
+			dataCols:    []string{"b", "ignored_c"},
+			types: ident.MapOf[string](
+				"a", "NUMBER",
+				"b", "VARCHAR2(1 CHAR)",
+				"c", "NUMBER",
+			),
+		},
 		// Check default value extraction
 		{
 			products: []types.Product{types.ProductCockroachDB, types.ProductMariaDB,