VirtualColumn (Apache Calcite API)

java.lang.Object
- org.apache.calcite.adapter.druid.VirtualColumn

All Implemented Interfaces:

DruidJson
```
public class VirtualColumn
extends java.lang.Object
implements DruidJson
```
Druid Json Expression based Virtual Column. Virtual columns is used as "projection" concept throughout Druid using expression.

Nested Class Summary

Nested Classes
Modifier and Type Class Description

static class VirtualColumn.Builder
Virtual Column Builder

Field Summary

Fields
Modifier and Type Field Description

private java.lang.String expression

private java.lang.String name

private DruidType outputType

Constructor Summary

Constructors
Constructor Description

VirtualColumn(java.lang.String name, java.lang.String expression, DruidType outputType)

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`static VirtualColumn.Builder`	`builder()`
`java.lang.String`	`getExpression()`
`java.lang.String`	`getName()`
`DruidType`	`getOutputType()`
`void`	`write(com.fasterxml.jackson.core.JsonGenerator generator)`

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

name
```
private final java.lang.String name
```

expression

private final java.lang.String expression

outputType
```
private final DruidType outputType
```

Constructor Detail

VirtualColumn

public VirtualColumn(java.lang.String name,
                     java.lang.String expression,
                     DruidType outputType)

Method Detail

write

public void write(com.fasterxml.jackson.core.JsonGenerator generator)
           throws java.io.IOException

Specified by:: write in interface DruidJson
Throws:: java.io.IOException

getName
```
public java.lang.String getName()
```

getExpression

public java.lang.String getExpression()

getOutputType
```
public DruidType getOutputType()
```

builder

public static VirtualColumn.Builder builder()