public interface SchemaFactory
Schema
objects.
A schema factory allows you to include a custom schema in a model file. For example, here is a model that contains a custom schema whose tables read CSV files. (See the example CSV adapter for more details about this particular adapter.)
{ "version": "1.0", "defaultSchema": "SALES", "schemas": [ { "name": "SALES", "type": "custom", "factory": "org.apache.calcite.adapter.csv.CsvSchemaFactory", "mutable": true, "operand": { directory: "target/test-classes/sales" }, "tables": [ { "name": "FEMALE_EMPS", "type": "view", "sql": "SELECT * FROM emps WHERE gender = 'F'" } ] } ] }
If you do not wish to allow model authors to add additional tables (including views) to an instance of your schema, specify 'mutable: false'.
A class that implements SchemaFactory specified in a schema must have a public default constructor.
Modifier and Type | Method and Description |
---|---|
Schema |
create(SchemaPlus parentSchema,
java.lang.String name,
java.util.Map<java.lang.String,java.lang.Object> operand)
Creates a Schema.
|
Schema create(SchemaPlus parentSchema, java.lang.String name, java.util.Map<java.lang.String,java.lang.Object> operand)
parentSchema
- Parent schemaname
- Name of this schemaoperand
- The "operand" JSON propertyCopyright © 2012–2019 The Apache Software Foundation. All rights reserved.