fix(gdb): strip quote chars from schema in Model.TableFields

When performing cross-database JOINs with soft-delete, the schema name
parsed from `schema`.`table` format retains database-specific quote
characters. These quoted schema names break information_schema WHERE
clause queries in TableFields lookups.

Strip quote characters from usedSchema in Model.TableFields, matching
the existing unquoting pattern used for usedTable via
guessPrimaryTableName.

fixes gogf#4725

Author: lingcoder

database/gdb/gdb_model_utility.go

@@ -37,6 +37,12 @@ func (m *Model) TableFields(tableStr string, schema ...string) (fields map[strin
 		usedTable  = m.db.GetCore().guessPrimaryTableName(tableStr)
 		usedSchema = gutil.GetOrDefaultStr(m.schema, schema...)
 	)
+	// Strip quote characters from schema name, as it may come from cross-database
+	// table parsing (e.g., `schema`.`table`) and contain database-specific quote chars.
+	charL, charR := m.db.GetChars()
+	if usedSchema != "" && (charL != "" || charR != "") {
+		usedSchema = gstr.Trim(usedSchema, charL+charR)
+	}
 	// Sharding feature.
 	usedSchema, err = m.getActualSchema(ctx, usedSchema)
 	if err != nil {