Package com.github.collinalpert.java2db.queries

Class EntityQuery<E extends BaseEntity>

  • All Implemented Interfaces:
    Queryable<E>, SingleQueryable<E>
    Direct Known Subclasses:
    AsyncEntityQuery
    public class EntityQuery<E extends BaseEntity>
extends SingleEntityQuery<E>
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

    • Constructor Summary

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

    • Method Summary

      Modifier and Type Method Description
      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​(OrderTypes orderType, com.github.collinalpert.lambda2sql.functions.SqlFunction<E,​?> function)
      Sets an ORDER BY clauses for the DQL statement with a sorting order option.
      EntityQuery<E> orderBy​(OrderTypes orderType, com.github.collinalpert.lambda2sql.functions.SqlFunction<E,​?>[] functions)
      Sets multiple ORDER BY clauses for the DQL statement with a sorting order option.
      EntityQuery<E> orderBy​(OrderTypes orderType, java.util.List<com.github.collinalpert.lambda2sql.functions.SqlFunction<E,​?>> functions)
      Sets multiple ORDER BY clauses for the DQL statement with a sorting order option.
      EntityQuery<E> orderBy​(com.github.collinalpert.lambda2sql.functions.SqlFunction<E,​?> function)
      Sets an ORDER BY clauses for the DQL statement.
      EntityQuery<E> orderBy​(com.github.collinalpert.lambda2sql.functions.SqlFunction<E,​?>[] functions)
      Sets multiple ORDER BY clauses for the DQL statement.
      EntityQuery<E> orderBy​(java.util.List<com.github.collinalpert.lambda2sql.functions.SqlFunction<E,​?>> functions)
      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.
      E[] toArray()
      Executes a new query and returns the result as an array.
      java.util.List<E> toList()
      Executes the query and returns the result as a List
      java.util.stream.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

    • Constructor Detail

      • EntityQuery

        public EntityQuery​(java.lang.Class<E> type)
        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 Detail

      • where

        public EntityQuery<E> where​(com.github.collinalpert.lambda2sql.functions.SqlPredicate<E> predicate)
        Sets or appends a WHERE clause for the DQL statement.
        Overrides:
        where in class SingleEntityQuery<E extends BaseEntity>
        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.
        Overrides:
        orWhere in class SingleEntityQuery<E extends BaseEntity>
        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 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​(java.util.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​(OrderTypes orderType,
                              com.github.collinalpert.lambda2sql.functions.SqlFunction<E,​?> function)
        Sets an ORDER BY clauses for the DQL statement with a sorting order option.
        Parameters:
        orderType - The direction to order by. Can be either ascending or descending.
        function - The column to order by.
        Returns:
        This EntityQuery object, now with a ORDER BY clause.

      • orderBy

        public EntityQuery<E> orderBy​(OrderTypes orderType,
                              com.github.collinalpert.lambda2sql.functions.SqlFunction<E,​?>[] functions)
        Sets multiple ORDER BY clauses for the DQL statement with a sorting order option. The resulting ORDER BY statement will coalesce the passed columns.
        Parameters:
        orderType - The direction to order by. Can be either ascending or descending.
        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​(OrderTypes orderType,
                              java.util.List<com.github.collinalpert.lambda2sql.functions.SqlFunction<E,​?>> functions)
        Sets multiple ORDER BY clauses for the DQL statement with a sorting order option. The resulting ORDER BY statement will coalesce the passed columns.
        Parameters:
        orderType - The direction to order by. Can be either ascending or descending.
        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.

      • 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.
        Overrides:
        project in class SingleEntityQuery<E extends BaseEntity>
        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.

      • toList

        public java.util.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 java.util.stream.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.