org.apache.flink.table.operations.utils.factories

Class ColumnOperationUtils

java.lang.Object

org.apache.flink.table.operations.utils.factories.ColumnOperationUtils

@Internal
public final class ColumnOperationUtils
extends Object

Utility class for creating projection expressions from column operation.

Method Summary

Modifier and Type	Method and Description
static List<org.apache.flink.table.expressions.Expression>	addOrReplaceColumns(List<String> inputFields, List<org.apache.flink.table.expressions.Expression> newExpressions) Creates a projection list that adds new or replaces existing (if a column with corresponding name already exists) columns.
static List<org.apache.flink.table.expressions.Expression>	dropFields(List<String> inputFields, List<org.apache.flink.table.expressions.Expression> dropExpressions) Creates a projection list that removes given columns.
static List<org.apache.flink.table.expressions.Expression>	renameColumns(List<String> inputFields, List<org.apache.flink.table.expressions.Expression> newAliases) Creates a projection list that renames existing columns to new names.

Methods inherited from class java.lang.Object

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

Method Detail

renameColumns

public static List<org.apache.flink.table.expressions.Expression> renameColumns(List<String> inputFields,
                                                                                List<org.apache.flink.table.expressions.Expression> newAliases)

Creates a projection list that renames existing columns to new names.

NOTE: Resulting expression are still unresolved.

Parameters:

inputFields - names of current columns

newAliases - new aliases for current columns

Returns:

projection expressions

addOrReplaceColumns

public static List<org.apache.flink.table.expressions.Expression> addOrReplaceColumns(List<String> inputFields,
                                                                                      List<org.apache.flink.table.expressions.Expression> newExpressions)

Creates a projection list that adds new or replaces existing (if a column with corresponding name already exists) columns.

NOTE: Resulting expression are still unresolved.

Parameters:

inputFields - names of current columns

newExpressions - new columns to add

Returns:

projection expressions

dropFields

public static List<org.apache.flink.table.expressions.Expression> dropFields(List<String> inputFields,
                                                                             List<org.apache.flink.table.expressions.Expression> dropExpressions)

Creates a projection list that removes given columns.

NOTE: Resulting expression are still unresolved.

Parameters:

inputFields - names of current columns

dropExpressions - columns to remove

Returns:

projection expressions