Hibernate Query Language Injection

21-04-2021 admin

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You need to use named parameters to avoid sql injection. Also (nothing to do with sql injection but with security in general) do not return the first result but use getSingleResult so if there are more than one results for some reason, the query will fail with NonUniqueResultException and login will not be succesful. Query query= sessionFactory.getCurrentSession.createQuery('from LoginInfo. The following code excerpt uses Hibernate's HQL syntax to build a dynamic query that's vulnerable to SQL injection. Simplified Query Language Syntax. This section briefly describes the syntax of the query language so that you can quickly move on to Example Queries. When you are ready to learn about the syntax in more detail, see Full Query Language Syntax. Select Statements. A select query has six clauses: SELECT, FROM, WHERE, GROUP BY, HAVING, and ORDER BY. There doesn't exist a NoSQL language standard, so injections for each vendor differ depending on the query language used and things like client permissions and data structure. NoSQL Injections with PHP. Most NoSQL injection examples across the web leverage PHP, and I'll start there as well. HQL or Hibernate Query Language is the object-oriented query language of Hibernate Framework. HQL is very similar to SQL except that we use Objects instead of table names, that makes it more close to object oriented programming. Table of Contents hide 1 Hibernate Query Language – HQL.

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Hibernate Query Language (HQL) is an object-oriented query language, similar to SQL, but instead of operating on tables and columns, HQL works with persistent objects and their properties. HQL queries are translated by Hibernate into conventional SQL queries, which in turns perform action on database.

Although you can use SQL statements directly with Hibernate using Native SQL, but I would recommend to use HQL whenever possible to avoid database portability hassles, and to take advantage of Hibernate's SQL generation and caching strategies.

Keywords like SELECT, FROM, and WHERE, etc., are not case sensitive, but properties like table and column names are case sensitive in HQL.

FROM Clause

You will use FROM clause if you want to load a complete persistent objects into memory. Following is the simple syntax of using FROM clause −

If you need to fully qualify a class name in HQL, just specify the package and class name as follows −

AS Clause

The AS clause can be used to assign aliases to the classes in your HQL queries, especially when you have the long queries. For instance, our previous simple example would be the following −

The AS keyword is optional and you can also specify the alias directly after the class name, as follows −

SELECT Clause

The SELECT clause provides more control over the result set then the from clause. If you want to obtain few properties of objects instead of the complete object, use the SELECT clause. Following is the simple syntax of using SELECT clause to get just first_name field of the Employee object −

It is notable here that Employee.firstName is a property of Employee object rather than a field of the EMPLOYEE table.

WHERE Clause

If you want to narrow the specific objects that are returned from storage, you use the WHERE clause. Following is the simple syntax of using WHERE clause −

ORDER BY Clause

To sort your HQL query's results, you will need to use the ORDER BY clause. You can order the results by any property on the objects in the result set either ascending (ASC) or descending (DESC). Following is the simple syntax of using ORDER BY clause −

If you wanted to sort by more than one property, you would just add the additional properties to the end of the order by clause, separated by commas as follows −

GROUP BY Clause

This clause lets Hibernate pull information from the database and group it based on a value of an attribute and, typically, use the result to include an aggregate value. Following is the simple syntax of using GROUP BY clause −

Using Named Parameters

Hibernate supports named parameters in its HQL queries. This makes writing HQL queries that accept input from the user easy and you do not have to defend against SQL injection attacks. Following is the simple syntax of using named parameters −

UPDATE Clause

Bulk updates are new to HQL with Hibernate 3, and delete work differently in Hibernate 3 than they did in Hibernate 2. The Query interface now contains a method called executeUpdate() for executing HQL UPDATE or DELETE statements.

The UPDATE clause can be used to update one or more properties of an one or more objects. Following is the simple syntax of using UPDATE clause −

DELETE Clause

The DELETE clause can be used to delete one or more objects. Following is the simple syntax of using DELETE clause −

INSERT Clause

HQL supports INSERT INTO clause only where records can be inserted from one object to another object. Following is the simple syntax of using INSERT INTO clause −

Aggregate Methods

HQL supports a range of aggregate methods, similar to SQL. They work the same way in HQL as in SQL and following is the list of the available functions −

Sr.No.	Functions & Description
1	avg(property name) The average of a property's value
2	*count(property name or )** The number of times a property occurs in the results
3	max(property name) The maximum value of the property values
4	min(property name) The minimum value of the property values
5	sum(property name) The sum total of the property values

The distinct keyword only counts the unique values in the row set. The following query will return only unique count −

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Pagination using Query

Hibernate Query Cache

There are two methods of the Query interface for pagination.