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 Summary

    Modifier and Type
    Method
    Description
    String[]
    getArgumentFields()
    Deprecated.
    Returns the names of all fields that the expression of the field computer accesses.
    Expression
    getExpression(ResolvedFieldReference[] fieldAccesses)
    Deprecated.
    Returns the Expression that computes the value of the field.
    org.apache.flink.api.common.typeinfo.TypeInformation<T>
    getReturnType()
    Deprecated.
    Returns the result type of the expression.
    void
    validateArgumentFields(org.apache.flink.api.common.typeinfo.TypeInformation<?>[] argumentFieldTypes)
    Deprecated.
    Validates that the fields that the expression references have the correct types.

  • Method Details

    • 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.