SingleEntityProjectionQuery (Java2DB 5.0 API)

java.lang.Object
- com.github.collinalpert.java2db.queries.SingleEntityProjectionQuery<E,R>

All Implemented Interfaces:

SingleQueryable<R>

Direct Known Subclasses:

AsyncSingleEntityProjectionQuery, EntityProjectionQuery
```
public class SingleEntityProjectionQuery<E extends BaseEntity,R>
extends java.lang.Object
implements SingleQueryable<R>
```
Author:

Collin Alpert

Field Summary

Fields
Modifier and Type Field Description

protected java.lang.Class<R> returnType

Constructor Summary

Constructors
Constructor	Description
`SingleEntityProjectionQuery(com.github.collinalpert.lambda2sql.functions.SqlFunction<E,R> projection, SingleEntityQuery<E> originalQuery)`

Method Summary

Modifier and Type	Method	Description
`java.util.Optional<R>`	`first()`	Gets the first value from the database result.
`java.lang.String`	`getQuery()`	Responsible for building and returning the individual DQL statement.

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

- Field Detail
  - returnType
```
protected final java.lang.Class<R> returnType
```
- Constructor Detail
  - SingleEntityProjectionQuery
```
public SingleEntityProjectionQuery(com.github.collinalpert.lambda2sql.functions.SqlFunction<E,R> projection,
                                   SingleEntityQuery<E> originalQuery)
```
- Method Detail
  - first
```
public java.util.Optional<R> first()
```
    Description copied from interface: SingleQueryable
    
    Gets the first value from the database result. This method should be used when only one result is expected.
    
    Specified by:
    
    first in interface SingleQueryable<E extends BaseEntity>
    
    Returns:
    
    The first row as an entity wrapped in an Optional if there is at least one row. Otherwise Optional.empty() is returned. If the value from the database is null, an empty Optional is also returned.
  - getQuery
```
public java.lang.String getQuery()
```
    Description copied from interface: SingleQueryable
    
    Responsible for building and returning the individual DQL statement.
    
    Specified by:
    
    getQuery in interface SingleQueryable<E extends BaseEntity>
    
    Returns:
    
    The DQL statement which fetches data from the database.