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https://issues.apache.org/jira/browse/FLINK-4686?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15529860#comment-15529860
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ASF GitHub Bot commented on FLINK-4686:
---------------------------------------
Github user twalthr commented on a diff in the pull request:
https://github.com/apache/flink/pull/2553#discussion_r80930699
--- Diff:
flink-libraries/flink-table/src/main/scala/org/apache/flink/api/table/Schema.scala
---
@@ -0,0 +1,89 @@
+/*
+ * 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.
+ */
+package org.apache.flink.api.table
+
+import org.apache.flink.api.common.typeinfo.TypeInformation
+
+/**
+ * A Schema represents a Table's structure
+ */
+class Schema(
+ val columnNames: Array[String],
+ val columnTypes: Array[TypeInformation[_]]) {
+
+ if (columnNames.length != columnTypes.length) {
+ throw new TableException(
+ "Number of column indexes and column names must be equal.")
+ }
+
+ // check uniqueness of field names
+ if (columnNames.toSet.size != columnTypes.length) {
+ throw new TableException(
+ "Table column names must be unique.")
+ }
+
+ val columnNameToIndex: Map[String, Int] = columnNames.zipWithIndex.toMap
+
+ /**
+ * Returns all type informations as an array
+ */
+ def getTypes: Array[TypeInformation[_]] = columnTypes
+
+ /**
+ * Returns the specified type information for the given column index
+ *
+ * @param columnIndex the index of the field
+ */
+ def getType(columnIndex: Int): TypeInformation[_] =
columnTypes(columnIndex)
+
+ /**
+ * Returns the specified type information for the given column name
+ *
--- End diff --
wrong indention
> Add possibility to get column names
> -----------------------------------
>
> Key: FLINK-4686
> URL: https://issues.apache.org/jira/browse/FLINK-4686
> Project: Flink
> Issue Type: New Feature
> Components: Table API & SQL
> Reporter: Timo Walther
> Assignee: Jark Wu
> Labels: starter
>
> For debugging and maybe for visualization in future (e.g. in a shell) it
> would be good to have the possibilty to get the names of {{Table}} columns.
> At the moment the user has no idea how the table columns are named; if they
> need to be matched with POJO fields for example.
> My suggestion:
> {code}
> Schema s = table.schema();
> TypeInformation<?> type = s.getType(1);
> TypeInformation<?> type = s.getType("col");
> String s = s.getColumnName(1);
> String[] s = s.getColumnNames();
> {code}
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