Dao (hrorm 0.5.0 API)

Type Parameters:

ENTITY - The type of the data to be persisted.

All Known Implementing Classes:

DaoImpl
```
public interface Dao<ENTITY>
```
A Dao is an interface that allows basic CRUD operations to be performed. Using a Dao, you can insert, select, update, and delete records.

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method and Description
`void`	`atomicDelete(ENTITY item)` Run a delete statement in the database within a transaction.
`long`	`atomicInsert(ENTITY item)` Insert a record into the database within a transaction that is managed within the Dao.
`void`	`atomicUpdate(ENTITY item)` Run an update statement to change the values in the database associated with an existing record.
`void`	`delete(ENTITY item)` Run a delete statement in the database.
`<T> T`	`foldingSelect(ENTITY template, T identity, BiFunction<T,ENTITY,T> accumulator, String... columnNames)` Computes a result based on the entities found by a select statement without realizing the entire list of found entities in memory.
`long`	`insert(ENTITY item)` Insert a record into the database.
`Queries`	`queries()` Access the `SQL` this `Dao` is using.
`ENTITY`	`select(long id)` Read a record from the database by its primary key.
`List<ENTITY>`	`selectAll()` Read all the records in the database of type ENTITY.
`ENTITY`	`selectByColumns(ENTITY item, String... columnNames)` Select a single record from the database by some search criteria.
`List<ENTITY>`	`selectMany(List<Long> ids)` Read several records from the database by their primary keys.
`List<ENTITY>`	`selectManyByColumns(ENTITY item, String... columnNames)` Select multiple records from the database by some search criteria.
`void`	`update(ENTITY item)` Run an update statement to change the values in the database associated with an existing record.

- Method Detail
  - insert
```
long insert(ENTITY item)
```
    Insert a record into the database.
    Depending on how the Dao was constucted (whether from a regular DaoBuilder or an IndirectDaoBuilder) a particular instance of this class may or may not attempt to mutate the state of the passed item by setting its primary key.
    
    Parameters:
    
    item - The instance to be inserted.
    
    Returns:
    
    The newly issued primary key of the record.
  - update
```
void update(ENTITY item)
```
    Run an update statement to change the values in the database associated with an existing record. Updates are applied by primary key.
    
    Parameters:
    
    item - An instance of the class with a populated primary key field and updated field values.
  - delete
```
void delete(ENTITY item)
```
    Run a delete statement in the database. Deletion is done by primary key.
    
    Parameters:
    
    item - An instance of type ENTITY with a populated primary key.
  - select
```
ENTITY select(long id)
```
    Read a record from the database by its primary key.
    
    Parameters:
    
    id - The primary key of the record desired.
    
    Returns:
    
    The populated instance of type ENTITY.
  - selectMany
```
List<ENTITY> selectMany(List<Long> ids)
```
    Read several records from the database by their primary keys.
    
    Parameters:
    
    ids - The primary keys of the records desired.
    
    Returns:
    
    A list of populated instances of type ENTITY.
  - selectAll
```
List<ENTITY> selectAll()
```
    Read all the records in the database of type ENTITY.
    No laziness or caching is involved here. This simply tries to instantiate all the records it can based on the full table.
    
    Returns:
    
    A list of populated instances of type ENTITY.
  - selectByColumns
```
ENTITY selectByColumns(ENTITY item,
                       String... columnNames)
```
    Select a single record from the database by some search criteria. If multiple records are found that match the passed item, an exception will be thrown.
    
    Parameters:
    
    item - An instance of type ENTITY with populated values corresponding to the column names to select by.
    
    columnNames - The names of the database columns
    
    Returns:
    
    The populated instance of type ENTITY with matching values with the passed item for the indicated columnNames.
  - selectManyByColumns
```
List<ENTITY> selectManyByColumns(ENTITY item,
                                 String... columnNames)
```
    Select multiple records from the database by some search criteria.
    
    Parameters:
    
    item - An instance of type ENTITY with populated values corresponding to the column names to select by.
    
    columnNames - The names of the database columns
    
    Returns:
    
    The populated instances of type ENTITY with matching values with the passed item for the indicated columnNames.
  - atomicInsert
```
long atomicInsert(ENTITY item)
```
    Insert a record into the database within a transaction that is managed within the Dao. The Dao will either commit or rollback the transaction and close the underlying Connection when complete.
    
    Parameters:
    
    item - The instance to be inserted.
    
    Returns:
    
    The newly issued primary key of the record.
  - atomicUpdate
```
void atomicUpdate(ENTITY item)
```
    Run an update statement to change the values in the database associated with an existing record. Updates are applied by primary key. The update will occur within a transaction that is managed within the Dao. The Dao will either commit or rollback the transaction and close the underlying Connection when complete.
    
    Parameters:
    
    item - An instance of the class with a populated primary key field and updated field values.
  - atomicDelete
```
void atomicDelete(ENTITY item)
```
    Run a delete statement in the database within a transaction. Deletion is done by primary key. The delete will occur within a transaction that is managed within the Dao. The Dao will either commit or rollback the transaction and close the underlying Connection when complete.
    
    Parameters:
    
    item - An instance of type ENTITY with a populated primary key.
  - foldingSelect
```
<T> T foldingSelect(ENTITY template,
                    T identity,
                    BiFunction<T,ENTITY,T> accumulator,
                    String... columnNames)
```
    Computes a result based on the entities found by a select statement without realizing the entire list of found entities in memory.
    
    Type Parameters:
    
    T - The type of the value to be computed.
    
    Parameters:
    
    template - An instance of type ENTITY with populated values corresponding to the column names to select by.
    
    identity - The identity element of the return type.
    
    accumulator - A function that computes the desired value based on the values seen thus far and the next instance of the entity found in the result set.
    
    columnNames - The names of the columns to include in the select where clause.
    
    Returns:
    
    The computed value based on the results found in the underlying store.
  - queries
```
Queries queries()
```
    Access the SQL this Dao is using.
    The SQL provided is suitable for being passed to a PreparedStatement.
    
    Returns:
    
    An object containing the literal SQL.

Interface Dao<ENTITY>

Method Summary

Method Detail

insert

update

delete

select

selectMany

selectAll

selectByColumns

selectManyByColumns

atomicInsert

atomicUpdate

atomicDelete

foldingSelect

queries