Package org.apache.flink.table.operations

Class ShowColumnsOperation

java.lang.Object

org.apache.flink.table.operations.AbstractShowOperation

org.apache.flink.table.operations.ShowColumnsOperation

All Implemented Interfaces:

ExecutableOperation, Operation, ShowOperation

@Internal
public class ShowColumnsOperation
extends AbstractShowOperation

Operation to describe a SHOW COLUMNS statement. The full syntax for SHOW COLUMNS is as followings:

 SHOW COLUMNS [ ( FROM | IN ) [catalog_name.]database_name.]table [ [NOT] (LIKE | ILIKE)
 <sql_like_pattern> ] statement
 

Nested Class Summary

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

ExecutableOperation.Context

Field Summary

Fields inherited from class org.apache.flink.table.operations.AbstractShowOperation

catalogName, likeOp, preposition

Constructor Summary

Constructors

Constructor	Description
ShowColumnsOperation(org.apache.flink.table.catalog.ObjectIdentifier tableIdentifier, String preposition, ShowLikeOperator likeOp)

Method Summary

Modifier and Type	Method	Description
TableResultInternal	execute(ExecutableOperation.Context ctx)	Executes the given operation and return the execution result.
protected String	getColumnName()
protected String	getOperationName()
org.apache.flink.table.catalog.ObjectIdentifier	getTableIdentifier()
protected Collection<String>	retrieveDataForTableResult(ExecutableOperation.Context ctx)

Methods inherited from class org.apache.flink.table.operations.AbstractShowOperation

asSummaryString, equals, getPrepositionSummaryString, hashCode, toString

Methods inherited from class java.lang.Object

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

Constructor Details

ShowColumnsOperation

public ShowColumnsOperation(org.apache.flink.table.catalog.ObjectIdentifier tableIdentifier,
 @Nullable
 String preposition,
 @Nullable
 ShowLikeOperator likeOp)

Method Details

getTableIdentifier

public org.apache.flink.table.catalog.ObjectIdentifier getTableIdentifier()

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

Overrides:

execute in class AbstractShowOperation

Parameters:

ctx - the context to execute the operation.

Returns:

the content of the execution result.

See Also:

• TableEnvironmentInternal.executeInternal(Operation)

getOperationName

protected String getOperationName()

Specified by:

getOperationName in class AbstractShowOperation

getColumnName

protected String getColumnName()

Specified by:

getColumnName in class AbstractShowOperation

retrieveDataForTableResult

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

Specified by:

retrieveDataForTableResult in class AbstractShowOperation