Package org.apache.flink.table.operations

Class AbstractShowOperation

java.lang.Object

org.apache.flink.table.operations.AbstractShowOperation

All Implemented Interfaces:

ExecutableOperation, Operation, ShowOperation

Direct Known Subclasses:

ShowCatalogsOperation, ShowColumnsOperation, ShowDatabasesOperation, ShowFunctionsOperation, ShowProceduresOperation, ShowTablesOperation, ShowViewsOperation

@Internal
public abstract class AbstractShowOperation
extends Object
implements ShowOperation

Base class for SHOW operations. It provides support of functionality:

 [ ( FROM | IN ) catalog_name] [ [NOT] (LIKE | ILIKE) <sql_like_pattern> ]
 

Nested Class Summary

Nested classes/interfaces inherited from interface org.apache.flink.table.operations.ExecutableOperation

ExecutableOperation.Context

Field Summary

Fields

Modifier and Type	Field	Description
protected String	catalogName
protected ShowLikeOperator	likeOp
protected String	preposition

Constructor Summary

Constructors

Constructor	Description
AbstractShowOperation(String catalogName, String preposition, ShowLikeOperator likeOp)

Method Summary

Modifier and Type	Method	Description
String	asSummaryString()	Returns a string that summarizes this operation for printing to a console.
boolean	equals(Object o)
TableResultInternal	execute(ExecutableOperation.Context ctx)	Executes the given operation and return the execution result.
protected abstract String	getColumnName()
protected abstract String	getOperationName()
protected String	getPrepositionSummaryString()
int	hashCode()
protected abstract Collection<String>	retrieveDataForTableResult(ExecutableOperation.Context ctx)
String	toString()

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

catalogName

@Nullable
protected final String catalogName

preposition

@Nullable
protected final String preposition

likeOp

@Nullable
protected final ShowLikeOperator likeOp

Constructor Detail

AbstractShowOperation

public AbstractShowOperation(@Nullable
                             String catalogName,
                             @Nullable
                             String preposition,
                             @Nullable
                             ShowLikeOperator likeOp)

Method Detail

retrieveDataForTableResult

protected abstract Collection<String> retrieveDataForTableResult(ExecutableOperation.Context ctx)

getOperationName

protected abstract String getOperationName()

getColumnName

protected abstract String getColumnName()

execute

public TableResultInternal execute(ExecutableOperation.Context ctx)

Description copied from interface: ExecutableOperation

Executes the given operation and return the execution result.

Specified by:

execute in interface ExecutableOperation

Parameters:

ctx - the context to execute the operation.

Returns:

the content of the execution result.

See Also:

TableEnvironmentInternal.executeInternal(Operation)

asSummaryString

public String asSummaryString()

Description copied from interface: Operation

Returns a string that summarizes this operation for printing to a console. An implementation might skip very specific properties.

Specified by:

asSummaryString in interface Operation

Returns:

summary string of this operation for debugging purposes

getPrepositionSummaryString

protected String getPrepositionSummaryString()

equals

public boolean equals(Object o)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object

toString

public String toString()

Overrides:

toString in class Object