org.hrorm

Interface KeylessDao<ENTITY>

Type Parameters:

ENTITY - The type of the data to be persisted.

All Known Subinterfaces:

Dao<ENTITY>

All Known Implementing Classes:

AbstractDao, DaoImpl, KeylessDaoImpl

public interface KeylessDao<ENTITY>

A KeylessDao supports some operations for inserting and selecting records in a database. Because a KeylessDao has no knowledge of a primary key, it cannot perform all the operations a full Dao can. In particular, it cannot update or delete records. Moreover, a keyless entity cannot be used in most relations. In general, a complete Dao should be preferred whenever possible.

Method Summary

Modifier and Type	Method and Description
Long	atomicInsert(ENTITY item) Insert a record into the database within a transaction that is managed within the Dao.
<T> T	foldingSelect(T identity, BiFunction<T,ENTITY,T> accumulator, Where where) 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.
BigDecimal	runBigDecimalFunction(SqlFunction function, String columnName, Where where) Computes an aggregated BigDecimal value, based on the select criteria specified and the given SqlFunction and column name.
Long	runLongFunction(SqlFunction function, String columnName, Where where) Computes an aggregated Long value, based on the select criteria specified and the given SqlFunction and column name.
List<ENTITY>	select() Read all the records in the database of type ENTITY.
List<ENTITY>	select(ENTITY template, Order order, String... columnNames) Select multiple records from the database by some search criteria in the required order.
List<ENTITY>	select(ENTITY template, String... columnNames) Select multiple records from the database by some search criteria.
List<ENTITY>	select(Order order) Read all the records in the database of type ENTITY in the required order.
List<ENTITY>	select(Where where) Run a select in the data store for entities matching the given where predicates.
List<ENTITY>	select(Where where, Order order) Run a select in the data store for entities matching the given where predicates returned in the order specified.
<T,U,V> List<Triplet<T,U,V>>	selectDistinct(String firstColumnName, String secondColumnName, String thirdColumnName, Where where) Select unique value triplets from the database for a particular triplet of columns.
<T,U> List<Pair<T,U>>	selectDistinct(String firstColumnName, String secondColumnName, Where where) Select unique value pairs from the database for a particular pair of columns.
<T> List<T>	selectDistinct(String columnName, Where where) Select unique values from the database for a particular column.
ENTITY	selectOne(ENTITY template, String... columnNames) Select a single record from the database by some search criteria.
ENTITY	selectOne(Where where) Select a single record from the database by some search criteria.

Method Detail

select

List<ENTITY> select()

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.

select

List<ENTITY> select(Where where)

Run a select in the data store for entities matching the given where predicates.

Parameters:

where - The predicates to drive selection.

Returns:

The matching results.

select

List<ENTITY> select(Order order)

Read all the records in the database of type ENTITY in the required order.

No laziness or caching is involved here. This simply tries to instantiate all the records it can based on the full table.

Parameters:

order - The ordering to use

Returns:

A list of populated instances of type ENTITY.

select

List<ENTITY> select(Where where,
                    Order order)

Run a select in the data store for entities matching the given where predicates returned in the order specified.

Parameters:

where - The predicates to drive selection.

order - The ordering to use

Returns:

The matching results.

select

List<ENTITY> select(ENTITY template,
                    String... columnNames)

Select multiple records from the database by some search criteria.

The SQL generated will specify a select by the column names passed, where the values are equal to the values specified in the passed template object. All the values must match, as the where clause will be formed by joining the various column names with 'AND'.

Parameters:

template - 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.

select

List<ENTITY> select(ENTITY template,
                    Order order,
                    String... columnNames)

Select multiple records from the database by some search criteria in the required order.

The SQL generated will specify a select by the column names passed, where the values are equal to the values specified in the passed template object. All the values must match, as the where clause will be formed by joining the various column names with 'AND'.

Parameters:

template - An instance of type ENTITY with populated values corresponding to the column names to select by.

order - The ordering to use

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.

selectOne

ENTITY selectOne(Where where)

Select a single record from the database by some search criteria.

If multiple records are found that match the given criteria, an exception will be thrown. If no records are found, null will be returned.

Parameters:

where - The predicates to drive selection.

Returns:

The populated instance of type ENTITY matching the given criteria

selectOne

ENTITY selectOne(ENTITY template,
                 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. If no records are found, null will be returned.

Parameters:

template - 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.

foldingSelect

<T> T foldingSelect(T identity,
                    BiFunction<T,ENTITY,T> accumulator,
                    Where where)

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:

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.

where - Predicates to drive selection of results

Returns:

The computed value based on the results found in the underlying store.

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, if there is one. Else, Optional.empty()

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, if there is one. Else, Optional.empty()

runLongFunction

Long runLongFunction(SqlFunction function,
                     String columnName,
                     Where where)

Computes an aggregated Long value, based on the select criteria specified and the given SqlFunction and column name.

Will run SQL that looks like this:

select FUNCTION(COLUMN) from TABLE where ...

Parameters:

function - The function to run

columnName - The column to apply the function to

where - Predicates to drive selection of results

Returns:

The value returned by applying the specified function to the values in the specified column in the matching results, or null if no results are found.

runBigDecimalFunction

BigDecimal runBigDecimalFunction(SqlFunction function,
                                 String columnName,
                                 Where where)

Computes an aggregated BigDecimal value, based on the select criteria specified and the given SqlFunction and column name.

Will run SQL that looks like this:

select FUNCTION(COLUMN) from TABLE where ...

Parameters:

function - The function to run

columnName - The column to apply the function to

where - Predicates to drive selection of results

Returns:

The value returned by applying the specified function to the values in the specified column in the matching results, or null if no results are found.

selectDistinct

<T> List<T> selectDistinct(String columnName,
                           Where where)

Select unique values from the database for a particular column.

The response will be of the type associated with the class being persisted, not the database type.

Type Parameters:

T - The type that this column represents, on the ENTITY, not necessarily the type of the database column.

Parameters:

columnName - The column to search for unique values.

where - Filters on the search.

Returns:

The distinct values found.

selectDistinct

<T,U> List<Pair<T,U>> selectDistinct(String firstColumnName,
                                     String secondColumnName,
                                     Where where)

Select unique value pairs from the database for a particular pair of columns.

The response will be of the types associated with the class being persisted, not the database type.

Type Parameters:

T - The type that the first column represents, on the ENTITY, not necessarily the type of the database column.

U - The type that the second column represents, on the ENTITY, not necessarily the type of the database column.

Parameters:

firstColumnName - The column name for to search for T values.

secondColumnName - The column name for to search for U values.

where - Filters on the search.

Returns:

The distinct values found.

selectDistinct

<T,U,V> List<Triplet<T,U,V>> selectDistinct(String firstColumnName,
                                            String secondColumnName,
                                            String thirdColumnName,
                                            Where where)

Select unique value triplets from the database for a particular triplet of columns.

The response will be of the types associated with the class being persisted, not the database type.

Type Parameters:

T - The type that the first column represents, on the ENTITY, not necessarily the type of the database column.

U - The type that the second column represents, on the ENTITY, not necessarily the type of the database column.

V - The type that the second column represents, on the ENTITY, not necessarily the type of the database column.

Parameters:

firstColumnName - The column name for to search for T values.

secondColumnName - The column name for to search for U values.

thirdColumnName - The column name for to search for V values.

where - Filters on the search.

Returns:

The distinct values found.