wuchong commented on a change in pull request #13909: URL: https://github.com/apache/flink/pull/13909#discussion_r518104838
########## File path: docs/dev/table/connectors/formats/single-field.md ########## @@ -0,0 +1,151 @@ +--- +title: "Single Field Format" +nav-title: SingleField +nav-parent_id: sql-formats +nav-pos: 7 +--- +<!-- +Licensed to the Apache Software Foundation (ASF) under one +or more contributor license agreements. See the NOTICE file +distributed with this work for additional information +regarding copyright ownership. The ASF licenses this file +to you under the Apache License, Version 2.0 (the +"License"); you may not use this file except in compliance +with the License. You may obtain a copy of the License at + + http://www.apache.org/licenses/LICENSE-2.0 + +Unless required by applicable law or agreed to in writing, +software distributed under the License is distributed on an +"AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY +KIND, either express or implied. See the License for the +specific language governing permissions and limitations +under the License. +--> + +<span class="label label-info">Format: Serialization Schema</span> +<span class="label label-info">Format: Deserialization Schema</span> + +* This will be replaced by the TOC +{:toc} + +The SingleField format allows to read and write data where the data contains only a single field, and that field is not wrapped within a JSON object, or an Avro record. + +Currently, the SingleField format supports `String`, `byte[]` and primitive type. + +Note: this format encodes `null` values as `null` `byte[]`. This may have limitation when used in `upsert-kafka`, because `upsert-kafka` treats `null` values as a tombstone message (DELETE on the key). Therefore, we recommend avoiding using `upsert-kafka` connector and `single-field` format if the field can have a `null` value. Review comment: Yes. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: [email protected]
