Package com.github.collinalpert.java2db.queries

Class EntityQuery<E extends BaseEntity>

java.lang.Object
com.github.collinalpert.java2db.queries.EntityQuery<E>
All Implemented Interfaces:
Queryable<E>
Direct Known Subclasses:
AsyncEntityQuery
public class EntityQuery<E extends BaseEntity>
extends Object
implements Queryable<E>
A class representing a DQL statement with different options, including where clauses, order by clauses and limits. It also automatically joins foreign keys so the corresponding entities (marked with the ForeignKeyEntity attribute) can be filled.
Author:
Collin Alpert

  • Field Summary

    Fields 
    Modifier and Type Field Description
    protected ConnectionConfiguration connectionConfiguration  
    protected IQueryBuilder<E> queryBuilder  
    protected QueryParameters<E> queryParameters  

  • Constructor Summary

    Constructors 
    Constructor Description
    EntityQuery​(Class<E> type, ConnectionConfiguration connectionConfiguration)
    Constructor for creating a DQL statement for a given entity.

  • Method Summary

    Modifier and Type Method Description
    EntityQuery<E> distinct()
    Adds a DISTINCT modifier to the query.
    Optional<E> first()
    Gets the first record of a result.
    String getQuery()
    Responsible for building and returning the individual DQL statement.
    protected String getTableName()
    Gets the table name which this query targets.
    EntityQuery<E> groupBy​(com.github.collinalpert.lambda2sql.functions.SqlFunction<E,​?> groupBy)  
    EntityQuery<E> groupBy​(com.github.collinalpert.lambda2sql.functions.SqlFunction<E,​?>... groupBy)  
    EntityQuery<E> limit​(int limit)
    Limits the result of the rows returned to a maximum of the passed integer.
    EntityQuery<E> limit​(int limit, int offset)
    Limits the result of the rows returned to a maximum of the passed integer with an offset.
    EntityQuery<E> orderBy​(com.github.collinalpert.lambda2sql.functions.SqlFunction<E,​?> function)
    Sets a single column as the ORDER BY clause for the DQL statement in an ascending manner.
    EntityQuery<E> orderBy​(com.github.collinalpert.lambda2sql.functions.SqlFunction<E,​?>[] functions)
    Sets multiple ORDER BY clauses for the DQL statement.
    EntityQuery<E> orderBy​(com.github.collinalpert.lambda2sql.functions.SqlFunction<E,​?>[] functions, OrderTypes orderType)
    Sets multiple ORDER BY clauses for the DQL statement.
    EntityQuery<E> orderBy​(com.github.collinalpert.lambda2sql.functions.SqlFunction<E,​?> function, OrderTypes orderType)
    Sets an ORDER BY clauses for the DQL statement.
    EntityQuery<E> orderBy​(List<com.github.collinalpert.lambda2sql.functions.SqlFunction<E,​?>> functions)
    Sets multiple ORDER BY clauses for the DQL statement.
    EntityQuery<E> orderBy​(List<com.github.collinalpert.lambda2sql.functions.SqlFunction<E,​?>> functions, OrderTypes orderType)
    Sets multiple ORDER BY clauses for the DQL statement.
    EntityQuery<E> orWhere​(com.github.collinalpert.lambda2sql.functions.SqlPredicate<E> predicate)
    Sets or appends an OR WHERE clause to the DQL statement.
    <R> Queryable<R> project​(com.github.collinalpert.lambda2sql.functions.SqlFunction<E,​R> projection)
    Selects only a single column from a table.
    EntityQuery<E> thenBy​(com.github.collinalpert.lambda2sql.functions.SqlFunction<E,​?> function)
    Sets a single column as the ORDER BY clause for the DQL statement in an ascending manner.
    EntityQuery<E> thenBy​(com.github.collinalpert.lambda2sql.functions.SqlFunction<E,​?>[] functions)
    Sets multiple ORDER BY clauses for the DQL statement.
    EntityQuery<E> thenBy​(com.github.collinalpert.lambda2sql.functions.SqlFunction<E,​?>[] functions, OrderTypes orderType)
    Sets multiple ORDER BY clauses for the DQL statement.
    EntityQuery<E> thenBy​(com.github.collinalpert.lambda2sql.functions.SqlFunction<E,​?> function, OrderTypes orderType)
    Sets an ORDER BY clauses for the DQL statement.
    EntityQuery<E> thenBy​(List<com.github.collinalpert.lambda2sql.functions.SqlFunction<E,​?>> functions)
    Sets multiple ORDER BY clauses for the DQL statement.
    EntityQuery<E> thenBy​(List<com.github.collinalpert.lambda2sql.functions.SqlFunction<E,​?>> functions, OrderTypes orderType)
    Sets multiple ORDER BY clauses for the DQL statement.
    E[] toArray()
    Executes a new query and returns the result as an array.
    List<E> toList()
    Executes the query and returns the result as a List
    <K,​ V> Map<K,​V> toMap​(Function<E,​K> keyMapping, Function<E,​V> valueMapping)
    Executes a new query and returns the result as a Map.
    Set<E> toSet()
    Executes the query and returns the result as a Set.
    Stream<E> toStream()
    Executes the query and returns the result as a Stream
    EntityQuery<E> where​(com.github.collinalpert.lambda2sql.functions.SqlPredicate<E> predicate)
    Sets or appends a WHERE clause for the DQL statement.

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

    Methods inherited from interface com.github.collinalpert.java2db.queries.Queryable

    toMap

  • Field Details

  • Constructor Details

    • EntityQuery

      public EntityQuery​(Class<E> type, ConnectionConfiguration connectionConfiguration)
      Constructor for creating a DQL statement for a given entity. This constructor should not be used directly, but through the DQL methods defined in the BaseService.
      Parameters:
      type - The entity to query.

  • Method Details

    • where

      public EntityQuery<E> where​(com.github.collinalpert.lambda2sql.functions.SqlPredicate<E> predicate)
      Sets or appends a WHERE clause for the DQL statement.
      Parameters:
      predicate - The predicate describing the WHERE clause.
      Returns:
      This EntityQuery object, now with an (appended) WHERE clause.

    • orWhere

      public EntityQuery<E> orWhere​(com.github.collinalpert.lambda2sql.functions.SqlPredicate<E> predicate)
      Sets or appends an OR WHERE clause to the DQL statement.
      Parameters:
      predicate - The predicate describing the OR WHERE clause.
      Returns:
      This EntityQuery object, now with an (appended) OR WHERE clause.

    • orderBy

      public EntityQuery<E> orderBy​(com.github.collinalpert.lambda2sql.functions.SqlFunction<E,​?> function)
      Sets a single column as the ORDER BY clause for the DQL statement in an ascending manner.
      Parameters:
      function - The column to order by.
      Returns:
      This EntityQuery object, now with a ORDER BY clause.

    • orderBy

      public EntityQuery<E> orderBy​(com.github.collinalpert.lambda2sql.functions.SqlFunction<E,​?> function, OrderTypes orderType)
      Sets an ORDER BY clauses for the DQL statement.
      Parameters:
      function - The column to order by.
      Returns:
      This EntityQuery object, now with a ORDER BY clause.

    • orderBy

      public EntityQuery<E> orderBy​(com.github.collinalpert.lambda2sql.functions.SqlFunction<E,​?>[] functions)
      Sets multiple ORDER BY clauses for the DQL statement. The resulting ORDER BY statement will coalesce the passed columns.
      Parameters:
      functions - The columns to order by in a coalescing manner.
      Returns:
      This EntityQuery object, now with a coalesced ORDER BY clause.

    • orderBy

      public EntityQuery<E> orderBy​(com.github.collinalpert.lambda2sql.functions.SqlFunction<E,​?>[] functions, OrderTypes orderType)
      Sets multiple ORDER BY clauses for the DQL statement. The resulting ORDER BY statement will coalesce the passed columns.
      Parameters:
      functions - The columns to order by in a coalescing manner.
      Returns:
      This EntityQuery object, now with a coalesced ORDER BY clause.

    • orderBy

      public EntityQuery<E> orderBy​(List<com.github.collinalpert.lambda2sql.functions.SqlFunction<E,​?>> functions)
      Sets multiple ORDER BY clauses for the DQL statement. The resulting ORDER BY statement will coalesce the passed columns.
      Parameters:
      functions - The columns to order by in a coalescing manner.
      Returns:
      This EntityQuery object, now with a coalesced ORDER BY clause.

    • orderBy

      public EntityQuery<E> orderBy​(List<com.github.collinalpert.lambda2sql.functions.SqlFunction<E,​?>> functions, OrderTypes orderType)
      Sets multiple ORDER BY clauses for the DQL statement. The resulting ORDER BY statement will coalesce the passed columns.
      Parameters:
      functions - The columns to order by in a coalescing manner.
      Returns:
      This EntityQuery object, now with a coalesced ORDER BY clause.

    • groupBy

      public EntityQuery<E> groupBy​(com.github.collinalpert.lambda2sql.functions.SqlFunction<E,​?> groupBy)

    • groupBy

      public EntityQuery<E> groupBy​(com.github.collinalpert.lambda2sql.functions.SqlFunction<E,​?>... groupBy)

    • thenBy

      public EntityQuery<E> thenBy​(com.github.collinalpert.lambda2sql.functions.SqlFunction<E,​?> function)
      Sets a single column as the ORDER BY clause for the DQL statement in an ascending manner.
      Parameters:
      function - The column to order by.
      Returns:
      This EntityQuery object, now with a ORDER BY clause.

    • thenBy

      public EntityQuery<E> thenBy​(com.github.collinalpert.lambda2sql.functions.SqlFunction<E,​?> function, OrderTypes orderType)
      Sets an ORDER BY clauses for the DQL statement.
      Parameters:
      function - The column to order by.
      Returns:
      This EntityQuery object, now with a ORDER BY clause.

    • thenBy

      public EntityQuery<E> thenBy​(com.github.collinalpert.lambda2sql.functions.SqlFunction<E,​?>[] functions)
      Sets multiple ORDER BY clauses for the DQL statement. The resulting ORDER BY statement will coalesce the passed columns.
      Parameters:
      functions - The columns to order by in a coalescing manner.
      Returns:
      This EntityQuery object, now with a coalesced ORDER BY clause.

    • thenBy

      public EntityQuery<E> thenBy​(com.github.collinalpert.lambda2sql.functions.SqlFunction<E,​?>[] functions, OrderTypes orderType)
      Sets multiple ORDER BY clauses for the DQL statement. The resulting ORDER BY statement will coalesce the passed columns.
      Parameters:
      functions - The columns to order by in a coalescing manner.
      Returns:
      This EntityQuery object, now with a coalesced ORDER BY clause.

    • thenBy

      public EntityQuery<E> thenBy​(List<com.github.collinalpert.lambda2sql.functions.SqlFunction<E,​?>> functions)
      Sets multiple ORDER BY clauses for the DQL statement. The resulting ORDER BY statement will coalesce the passed columns.
      Parameters:
      functions - The columns to order by in a coalescing manner.
      Returns:
      This EntityQuery object, now with a coalesced ORDER BY clause.

    • thenBy

      public EntityQuery<E> thenBy​(List<com.github.collinalpert.lambda2sql.functions.SqlFunction<E,​?>> functions, OrderTypes orderType)
      Sets multiple ORDER BY clauses for the DQL statement. The resulting ORDER BY statement will coalesce the passed columns.
      Parameters:
      functions - The columns to order by in a coalescing manner.
      Returns:
      This EntityQuery object, now with a coalesced ORDER BY clause.

    • limit

      public EntityQuery<E> limit​(int limit, int offset)
      Limits the result of the rows returned to a maximum of the passed integer with an offset. For example, the call .limit(10, 5) would return the rows 6-15.
      Parameters:
      limit - The maximum of rows to be returned.
      offset - The offset of the limit.
      Returns:
      This EntityQuery object, now with a LIMIT with an OFFSET.

    • limit

      public EntityQuery<E> limit​(int limit)
      Limits the result of the rows returned to a maximum of the passed integer.
      Parameters:
      limit - The maximum of rows to be returned.
      Returns:
      This EntityQuery object, now with a LIMIT.

    • distinct

      public EntityQuery<E> distinct()
      Adds a DISTINCT modifier to the query.
      Returns:
      This EntityQuery object, now with a DISTINCT clause.

    • project

      public <R> Queryable<R> project​(com.github.collinalpert.lambda2sql.functions.SqlFunction<E,​R> projection)
      Selects only a single column from a table. This is meant if you don't want to fetch an entire entity from the database.
      Type Parameters:
      R - The type of the column you want to retrieve.
      Parameters:
      projection - The column to project to.
      Returns:
      A queryable containing the projection.

    • first

      public Optional<E> first()
      Gets the first record of a result. This method should be used when only one record is expected, i.e. when filtering by a unique identifier such as an id.
      Specified by:
      first in interface Queryable<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.

    • toList

      public List<E> toList()
      Executes the query and returns the result as a List
      Specified by:
      toList in interface Queryable<E extends BaseEntity>
      Returns:
      A list of entities representing the result rows.

    • toStream

      public Stream<E> toStream()
      Executes the query and returns the result as a Stream
      Specified by:
      toStream in interface Queryable<E extends BaseEntity>
      Returns:
      A list of entities representing the result rows.

    • toArray

      public E[] toArray()
      Executes a new query and returns the result as an array.
      Specified by:
      toArray in interface Queryable<E extends BaseEntity>
      Returns:
      An array of entities representing the result rows.

    • toMap

      public <K,​ V> Map<K,​V> toMap​(Function<E,​K> keyMapping, Function<E,​V> valueMapping)
      Executes a new query and returns the result as a Map.
      Specified by:
      toMap in interface Queryable<E extends BaseEntity>
      Type Parameters:
      K - The type of the field representing the keys.
      V - The type of the field representing the values.
      Parameters:
      keyMapping - The field representing the keys of the map.
      valueMapping - The field representing the values of the map.
      Returns:
      A map containing the result of the query.

    • toSet

      public Set<E> toSet()
      Executes the query and returns the result as a Set.
      Specified by:
      toSet in interface Queryable<E extends BaseEntity>
      Returns:
      A set of entities representing the result rows.

    • getQuery

      public String getQuery()
      Description copied from interface: Queryable
      Responsible for building and returning the individual DQL statement.
      Specified by:
      getQuery in interface Queryable<E extends BaseEntity>
      Returns:
      The DQL statement which fetches data from the database.

    • getTableName

      protected String getTableName()
      Gets the table name which this query targets.
      Returns:
      The table name which this query targets.