org.apache.flink.table.catalog

Class ExternalSchemaTranslator

java.lang.Object

org.apache.flink.table.catalog.ExternalSchemaTranslator

@Internal
public final class ExternalSchemaTranslator
extends Object

Utility to derive a physical DataType, Schema, and projections when entering or leaving the table ecosystem from and to other APIs where TypeInformation is required.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	ExternalSchemaTranslator.InputResult Result of fromExternal(DataTypeFactory, TypeInformation, Schema).
static class	ExternalSchemaTranslator.OutputResult Result of fromExternal(DataTypeFactory, TypeInformation, Schema).

Constructor Summary

Constructors

Constructor and Description
ExternalSchemaTranslator()

Method Summary

Modifier and Type	Method and Description
static ExternalSchemaTranslator.InputResult	fromExternal(org.apache.flink.table.catalog.DataTypeFactory dataTypeFactory, org.apache.flink.api.common.typeinfo.TypeInformation<?> inputTypeInfo, org.apache.flink.table.api.Schema declaredSchema) Converts the given TypeInformation and an optional declared Schema (possibly incomplete) into the final ExternalSchemaTranslator.InputResult.
static ExternalSchemaTranslator.OutputResult	fromInternal(org.apache.flink.table.catalog.DataTypeFactory dataTypeFactory, org.apache.flink.table.catalog.ResolvedSchema inputSchema, org.apache.flink.table.types.AbstractDataType<?> targetDataType) Converts the given DataType into the final ExternalSchemaTranslator.OutputResult.
static ExternalSchemaTranslator.OutputResult	fromInternal(org.apache.flink.table.catalog.ResolvedSchema inputSchema, org.apache.flink.table.api.Schema declaredSchema) Converts the given DataType into the final ExternalSchemaTranslator.OutputResult.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

ExternalSchemaTranslator

public ExternalSchemaTranslator()

Method Detail

fromInternal

public static ExternalSchemaTranslator.OutputResult fromInternal(org.apache.flink.table.catalog.ResolvedSchema inputSchema,
                                                                 @Nullable
                                                                 org.apache.flink.table.api.Schema declaredSchema)

Converts the given DataType into the final ExternalSchemaTranslator.OutputResult.

This method serves three types of use cases:

• 1. Derive physical columns from the input schema.
• 2. Derive physical columns from the input schema but enrich with metadata column and primary key.
• 3. Entirely use declared schema.

fromInternal

public static ExternalSchemaTranslator.OutputResult fromInternal(org.apache.flink.table.catalog.DataTypeFactory dataTypeFactory,
                                                                 org.apache.flink.table.catalog.ResolvedSchema inputSchema,
                                                                 org.apache.flink.table.types.AbstractDataType<?> targetDataType)

Converts the given DataType into the final ExternalSchemaTranslator.OutputResult.

This method serves one type of use case:

• 1. Derive physical columns from the input data type.

fromExternal

public static ExternalSchemaTranslator.InputResult fromExternal(org.apache.flink.table.catalog.DataTypeFactory dataTypeFactory,
                                                                org.apache.flink.api.common.typeinfo.TypeInformation<?> inputTypeInfo,
                                                                @Nullable
                                                                org.apache.flink.table.api.Schema declaredSchema)

Converts the given TypeInformation and an optional declared Schema (possibly incomplete) into the final ExternalSchemaTranslator.InputResult.

This method serves three types of use cases:

• 1. Derive physical columns from the input type information.
• 2. Derive physical columns but merge them with declared computed columns and other schema information.
• 3. Derive and enrich physical columns and merge other schema information.