danny0405 commented on a change in pull request #9366: [FLINK-13359][docs] Add documentation for DDL introduction URL: https://github.com/apache/flink/pull/9366#discussion_r314667044
########## File path: docs/dev/table/ddl.md ########## @@ -0,0 +1,119 @@ +--- +title: "DDL" +nav-parent_id: tableapi +nav-pos: 0 +--- +<!-- +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. +--> + +The Table API and SQL are integrated in a joint API. The central concept of this API is a `Table` which serves as input and output of queries. This document shows all the DDL grammar Flink support, how to register a `Table`(or view) through DDL, how to drop a `Table`(or view) through DDL. + +* This will be replaced by the TOC +{:toc} + +Create Table +--------------------------------------- +{% highlight sql %} +CREATE [OR REPLACE] TABLE [catalog_name.][db_name.]table_name + [(col_name1 col_type1 [COMMENT col_comment1], ...)] + [COMMENT table_comment] + [PARTITIONED BY (col_name1, col_name2, ...)] + [WITH (key1=val1, key2=val2, ...)] +{% endhighlight %} + +Create a table with the given table properties. If a table with the same name already exists in the database, an exception is thrown except that *IF NOT EXIST* is declared. + +**OR REPLACE** + +If a table with the same name already exists in the database, replace it if this is declared. **Notes:** The OR REPLACE option is always false now. + +**PARTITIONED BY** + +Partition the created table by the specified columns. A directory is created for each partition if this table is used as a filesystem sink. + +**WITH OPTIONS** + +Table properties used to create a table source/sink. The properties are usually used to find and create the underlying connector. **Notes:** the key and value of expression `key1=val1` should both be string literal. + +See details in [Connect to External Systems](connect.html) for all the supported table properties of different connectors. + +**Notes:** The table name can be of two formats: 1. `catalog_name.db_name.table_name` 2. `table_name`. For `catalog_name.db_name.table_name`, the table would be registered into metastore with catalog named "catalog_name" and database named "db_name"; for `table_name`, the table would be registered into the current catalog and database of the execution table environment. Review comment: We won't support it in the future. ---------------------------------------------------------------- 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: us...@infra.apache.org With regards, Apache Git Services
