Package org.apache.flink.table.legacy.sources

Interface FieldComputer<T>

  • Type Parameters:
    T - The result type of the provided expression.
    All Known Implementing Classes:
    TimestampExtractor
    @Deprecated
@Internal
public interface FieldComputer<T>
    Deprecated.
    This interface will not be supported in the new source design around DynamicTableSource. Use the concept of computed columns instead. See FLIP-95 for more information.
    The FieldComputer interface returns an expression to compute the field of the table schema of a TableSource from one or more fields of the TableSource's return type.

    • Method Detail

      • getArgumentFields

        String[] getArgumentFields()
        Deprecated.
        Returns the names of all fields that the expression of the field computer accesses.
        Returns:
        An array with the names of all accessed fields.

      • getReturnType

        org.apache.flink.api.common.typeinfo.TypeInformation<T> getReturnType()
        Deprecated.
        Returns the result type of the expression.
        Returns:
        The result type of the expression.

      • validateArgumentFields

        void validateArgumentFields​(org.apache.flink.api.common.typeinfo.TypeInformation<?>[] argumentFieldTypes)
        Deprecated.
        Validates that the fields that the expression references have the correct types.
        Parameters:
        argumentFieldTypes - The types of the physical input fields.

      • getExpression

        Expression getExpression​(ResolvedFieldReference[] fieldAccesses)
        Deprecated.
        Returns the Expression that computes the value of the field.
        Parameters:
        fieldAccesses - Field access expressions for the argument fields.
        Returns:
        The expression to extract the timestamp from the TableSource return type.