Automatically create calcite schema based on user provided configurations of tab...

Automatically create calcite schema based on user provided configurations of table sources

https://github.com/apache/incubator-wayang/blob/d46f3c3f0fb963c2ee2640f00a106042fba55431/wayang-api/wayang-api-sql/src/main/java/org/apache/wayang/api/sql/calcite/schema/SchemaUtils.java#L32

```java

/*
* 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.wayang.api.sql.calcite.schema;

import org.apache.calcite.jdbc.CalciteConnection;
import org.apache.calcite.jdbc.CalciteSchema;
import org.apache.calcite.schema.SchemaPlus;
import org.apache.wayang.core.api.Configuration;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.util.Properties;

/**
* This class contains some hardcoded functions for creating calcite schema.
* TODO: Automatically create calcite schema based on user provided configurations of table sources
*/
public class SchemaUtils {

private static Properties getPostgresProperties() {
/** Hardcoded for testing **/
Properties info = new Properties();
info.put("model",
"inline:"
+ "{\n"
+ " version: '1.0',\n"
+ " defaultSchema: 'tpch',\n"
+ " schemas: [\n"
+ " {\n"
+ " name: 'postgres',\n"
+ " type: 'custom',\n"
+ " factory: 'org.apache.wayang.api.sql.calcite.jdbc.JdbcSchema$Factory',\n"
+ " operand: {\n"
+ " jdbcDriver: 'org.postgresql.Driver',\n"
+ " jdbcUrl: 'jdbc:postgresql://localhost:5432/tpch',\n"
+ " jdbcUser: 'user',\n"
+ " jdbcPassword: 'password'\n"
+ " }\n"
+ " }\n"
+ " ]\n"
+ "}");
return info;
}

private static Properties getFileProperties() {
Properties info = new Properties();
info.put("model",
"inline:"
+ "{\n"
+ " version: '1.0',\n"
+ " defaultSchema: 'tpch',\n"
+ " schemas: [ {\n"
+ " name: 'fs',\n"
+ " type: 'custom',\n"
+ " factory: 'org.apache.calcite.adapter.file.FileSchemaFactory',\n"
+ " operand: {\n"
+ " directory: '/data/Projects/databloom/test-data'\n"
+ " } \n"
+ " }\n"
+ " ]\n"
+ "}"
);
return info;
}

public static CalciteSchema getPostgresSchema(Configuration configuration) throws SQLException {
final Connection connection = DriverManager.getConnection("jdbc:calcite:", getPostgresProperties());
return getCalciteSchema(connection);
}

public static CalciteSchema getFileSchema(Configuration configuration) throws SQLException {
final Connection connection = DriverManager.getConnection("jdbc:calcite:", getFileProperties());
return getCalciteSchema(connection);
}

public static CalciteSchema getCalciteSchema(Connection connection) throws SQLException {
CalciteConnection calciteConnection = connection.unwrap(CalciteConnection.class);
final SchemaPlus schemaPlus = calciteConnection.getRootSchema();
CalciteSchema calciteSchema = CalciteSchema.from(schemaPlus);
return calciteSchema;
}
}

```

0fdef9320b429e35c9ea27527ce773624c5b88da

Start in wayang-api/wayang-api-sql/src/main/java/org/apache/wayang/api/sql/calcite/schema/SchemaUtils.java, especially getPostgresSchema, getFileSchema, and the Configuration parameter. Trace how the hardcoded Calcite properties describe table sources and determine how user-provided configurations should replace them. Done means Calcite schemas are created from those configurations rather than fixed PostgreSQL and file settings.

Written by the indexing model from the issue text.