ShowColumnsOperation (Flink : 2.0-SNAPSHOT API)

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)
 &lt;sql_like_pattern&gt; ] 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(ObjectIdentifier tableIdentifier, String preposition, ShowLikeOperator likeOp)

Method Summary

All Methods Instance Methods Concrete Methods
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()`
`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 Detail
  - ShowColumnsOperation
```
public ShowColumnsOperation(ObjectIdentifier tableIdentifier,
                            @Nullable
                            String preposition,
                            @Nullable
                            ShowLikeOperator likeOp)
```
- Method Detail
  - getTableIdentifier
```
public 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