koop-provider-snowflake

A configurable and reusable Snowflake provider for Koop

This provider creates a connection to Snowflake using the Snowflake supported Node.js driver and executes SQL queries against a configureable list of tables. Snowflake tables must contain a GEOGRAPHY column.

Features

configurable
supports multiple Snowflake table sources
supports query operation with where and geometry parameters
- only esriGeometryEnvelope is supported at this time

Usage

Once started, a Koop server including this provider supports routes like

/snowflake-provider/:host/:id/FeatureServer/:layer/query

where host can be any preferred value, id is the key used to look up a service definition in the configurable map of serviceDefinitions and layer is the index of a item in the service definition. See configuration instructions below.

For example, this route allows you to query the first configured service definition.

/snowflake-provider/rest/locations/FeatureServer/0/query

Configuration

The configuration includes required properties to create a Snowflake connection. The serviceDefinitions map enables unique service endpoints to expose the query operation on Snowflake tables.

serviceDefinitions

serviceIndex is the unique ID for this query endpoint, which targets one table.
tableName is the qualified Snowflake table name.
geographyField is the name of the required GEOGRAPHY column.
selectFields is the SELECT component of the SQL statement. For security purposes the client is not allowed to control the returned fields. At this time the client can't specify a subset of these fields.
maxReturnCount becomes the TOP n component of the SQL statement.

A configuration looks like this:

{
    "koopProviderSnowflake":{
        "snowflakeAccount":"<Your Account>",
        "snowflakeWarehouse":"<Your Data Warehouse>",
        "snowflakeUser":"<Your Username>",
        "snowflakePassword":"<Your Password>",
        "serviceDefinitions":{
            "locations": [
                {
                "serviceIndex":0,
                "serviceDesc":"Sample location data",
                "tableName":"DEMO.PUBLIC.LOCATIONS",
                "geographyField":"SHAPE",
                "selectFields":"ID,LOB,CONSTTYPE,YEARBUILT,LATITUDE,LONGITUDE",
                "maxReturnCount":5000,
                "geometryType":"esriGeometryPoint"
                }
            ]
        }
    }
}

Development

Run dev server

with Node.js

node server.js

A dev server will be running at http://localhost:8080. By default, it will use the default configuration config/default.json, which should be updated beforehand.

License

Licensed 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.

A copy of the license is available in the repository's License.txt file.

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