package io.ebean;
import java.io.Serializable;
import java.util.List;
import java.util.Optional;
import java.util.function.Consumer;
import java.util.function.Predicate;
/**
* Query object for performing native SQL queries that return SqlRow's.
* <p>
* Firstly note that you can use your own sql queries with <em>entity beans</em>
* by using the SqlSelect annotation. This should be your first approach when
* wanting to use your own SQL queries.
* </p>
* <p>
* If ORM Mapping is too tight and constraining for your problem then SqlQuery
* could be a good approach.
* </p>
* <p>
* The returned SqlRow objects are similar to a LinkedHashMap with some type
* conversion support added.
* </p>
* <p>
* <pre>{@code
*
* // its typically a good idea to use a named query
* // and put the sql in the orm.xml instead of in your code
*
* String sql = "select id, name from customer where name like :name and status_code = :status";
*
* SqlQuery sqlQuery = Ebean.createSqlQuery(sql);
* sqlQuery.setParameter("name", "Acme%");
* sqlQuery.setParameter("status", "ACTIVE");
*
* // execute the query returning a List of MapBean objects
* List<SqlRow> list = sqlQuery.findList();
*
* }</pre>
*/
public interface SqlQuery extends Serializable {
/**
* Execute the query returning a list.
*/
List<SqlRow> findList();
/**
* Execute the SqlQuery iterating a row at a time.
* <p>
* This streaming type query is useful for large query execution as only 1 row needs to be held in memory.
* </p>
*/
void findEach(Consumer<SqlRow> consumer);
/**
* Execute the SqlQuery iterating a row at a time with the ability to stop consuming part way through.
* <p>
* Returning false after processing a row stops the iteration through the query results.
* </p>
* <p>
* This streaming type query is useful for large query execution as only 1 row needs to be held in memory.
* </p>
*/
void findEachWhile(Predicate<SqlRow> consumer);
/**
* Execute the query returning a single row or null.
* <p>
* If this query finds 2 or more rows then it will throw a
* PersistenceException.
* </p>
*/
SqlRow findOne();
/**
* Execute the query returning an optional row.
*/
Optional<SqlRow> findOneOrEmpty();
/**
* Synonym for findOne().
*/
SqlRow findUnique();
/**
* The same as bind for named parameters.
*/
SqlQuery setParameter(String name, Object value);
/**
* The same as bind for positioned parameters.
*/
SqlQuery setParameter(int position, Object value);
/**
* Set the index of the first row of the results to return.
*/
SqlQuery setFirstRow(int firstRow);
/**
* Set the maximum number of query results to return.
*/
SqlQuery setMaxRows(int maxRows);
/**
* Set a timeout on this query.
* <p>
* This will typically result in a call to setQueryTimeout() on a
* preparedStatement. If the timeout occurs an exception will be thrown - this
* will be a SQLException wrapped up in a PersistenceException.
* </p>
*
* @param secs the query timeout limit in seconds. Zero means there is no limit.
*/
SqlQuery setTimeout(int secs);
/**
* A hint which for JDBC translates to the Statement.fetchSize().
* <p>
* Gives the JDBC driver a hint as to the number of rows that should be
* fetched from the database when more rows are needed for ResultSet.
* </p>
*/
SqlQuery setBufferFetchSizeHint(int bufferFetchSizeHint);
}