Java prepared statement dynamic parameters

Start your free trial. It is used for better performancehigh efficiency and prevention of SQL injection vulnerability. Before going further, let us have a brief introduction to SQL injection. SQL injection is a very popular and common web application vulnerability caused by improper handling of input data and its usage in database queries. An application vulnerable to SQL injection attack allows an attacker to execute arbitrary SQL queries, leading to database enumeration and data theft.

In worst cases, it can even lead to remote code execution and system takeover. Many large organizations have been found to be vulnerable to SQL injection, proving that this is a very common vulnerability and many developers are not very aware of SQL injection prevention techniques.

During development of an application, from the eyes of a developer it can be seen that it is prevalent to use user input as part of dynamic SQL queries. In past years, many input validation, data sanitization and input escaping techniques have been developed and implemented to prevent SQL injection.

But for one or the other reason, a flaw has been found in them or in the way they have been implemented, making them vulnerable. OWASP also recommends it as the first choice of prevention techniques for this vulnerability. Let us go forward and understand what happens when handling data with database queries in both vulnerable and secure implementations. This SQL query is used to fetch a single row from the users table to authenticate a user.

This input is expected from user only. Accepting input from user and using it as an input in SQL query makes it a dynamic query. Using dynamic queries with flawed input validation, input sanitization and escaping leads to an application being vulnerable to SQL injection vulnerability.

It may or may not have implemented input escaping before using it in the SQL query. With this SQL query built and then executed, it would have worked flawlessly. But an authentication query with SQL injection could have been like this:. Due to this, using dynamic queries is not a good development strategy.

SQL Parameterized Query comes to rescue here because it forces the user to implement the logic of SQL query first and then inserting user input into it.We can execute parameterized query using Spring JdbcTemplate by the help of execute method of JdbcTemplate class. To use parameterized query, we pass the instance of PreparedStatementCallback in the execute method.

Java PreparedStatement IN clause alternatives

It processes the input parameters and output results. In such case, you don't need to care about single and double quotes. You must understand the concept of annonymous class to understand the code of the method. The DriverManagerDataSource is used to contain the information about the database such as driver class name, connnection URL, username and password.

java prepared statement dynamic parameters

So, we need to provide the reference of DriverManagerDataSource object in the JdbcTemplate class for the datasource property. Here, we are using the JdbcTemplate object in the EmployeeDao class, so we are passing it by the setter method but you can use constructor also.

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This class gets the bean from the applicationContext. JavaTpoint offers too many high quality services. Mail us on hr javatpoint. Please mail your requirement at hr javatpoint. Duration: 1 week to 2 week. Spring Tutorial.

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PreparedStatement; import java. SQLException; import org.

JDBC PreparedStatement – Insert a row

DataAccessException; import org. JdbcTemplate; import org. ApplicationContext; import org. Spring Boot. Selenium Py.This object can then be used to efficiently execute this statement multiple times. Note: The setter methods setShortsetStringand so on for setting IN parameter values must specify types that are compatible with the defined SQL type of the input parameter.

If arbitrary parameter type conversions are required, the method setObject should be used with a target SQL type. Array object. BigDecimal value. Blob object. Clob object. Date value using the default time zone of the virtual machine that is running the application. Date value, using the given Calendar object.

NClob object. RowId object. Time value. Time value, using the given Calendar object. Timestamp value. Timestamp value, using the given Calendar object.

java prepared statement dynamic parameters

URL value. Note: You must specify the parameter's SQL type. Parameters: parameterIndex - the first parameter is 1, the second is 2, Data will be read from the stream as needed until end-of-file is reached.

Solution 1: Subclass

Note: This stream object can either be a standard Java stream object or your own subclass that implements the standard interface. Sets the designated parameter to the given input stream, which will have the specified number of bytes.

InputStream object. The data will be read from the stream as needed until end-of-file is reached. In general, parameter values remain in force for repeated use of a statement. Setting a parameter value automatically clears its previous value. However, in some cases it is useful to immediately release the resources used by the current parameter values; this can be done by calling the method clearParameters.

This method is like the method setObject above, except that it assumes a scale of zero. The second parameter must be of type Object ; therefore, the java. The given argument will be converted to the corresponding SQL type before being sent to the database.

Note that this method may be used to pass datatabase- specific abstract data types, by using a driver-specific Java type. Note: Not all databases allow for a non-typed Null to be sent to the backend. For maximum portability, the setNull or the setObject int parameterIndex, Object x, int sqlType method should be used instead of setObject int parameterIndex, Object x.By using our site, you acknowledge that you have read and understand our Cookie PolicyPrivacy Policyand our Terms of Service.

The dark mode beta is finally here. Change your preferences any time. Stack Overflow for Teams is a private, secure spot for you and your coworkers to find and share information. I have a common class for all DAO's where we will read queries and execute them as below.

I will send parameters from DAO to this class. We are only simple JDBC in our project.

java prepared statement dynamic parameters

Look at this page example. Your query should contain? Maybe this interesting to you Named Parameters for PreparedStatement. Learn more. Asked 7 years, 8 months ago.

java prepared statement dynamic parameters

Active 1 year, 4 months ago. Viewed 52k times. Pshemo k 17 17 gold badges silver badges bronze badges. Java P Java P 1, 5 5 gold badges 19 19 silver badges 38 38 bronze badges. Please don't use too much bold style. Active Oldest Votes. I know that this is old school code, but just to give some minimalistic example Andrey Borisov Andrey Borisov 2, 14 14 silver badges 17 17 bronze badges.

What about ps.

Stored Procedure Tutorial - Create Dynamic Query to Variable With Parameter

Vladislav Troyan Vladislav Troyan 87 1 1 silver badge 4 4 bronze badges. Sign up or log in Sign up using Google.The problems with PreparedStatement stem from its syntax for parameters. Parameters are anonymous and accessed by index as in the following:. For small queries with one or two parameters, this is not an issue. However, for larger queries, keeping track of the indices becomes very difficult. The developer must carefully read through the SQL statement and count question marks to determine where a parameter is inserted.

If a parameter is removed or inserted, all following parameter indices must be renumbered. Obvioulsy this can be problematic if the parameter is toward the beginning of the statement and there are several parameters, or if a query is restructured so the parameters appear in a different order. Another inconvenience is setting multiple parameters which may be logically the same. This is particularly effective for stability when parameters are being inserted and deleted.

However, the code is still no more readable, and the programmer must still take care to ensure that the parameters are listed in the same order they are used in the query. This brings us to my class which is called for lack of a better name NamedParameterStatement. The syntax is the same as PreparedStatement except that, instead of question marks, parameters are represented as a colon followed by an identifier. Behind the scenes, the class works by replacing the parameter markers with questions marks and creating a PreparedStatement.

A mapping is kept between parameter names and their indices. This mapping is referred to when the parameters are injected. The two classes are mutually compatible so programmers may use PreparedStatement for some queries and NamedParameterStatement for others as they see fit. The time spent translating the query and looking up parameter indices is actually minimal compared to the time it takes to execute the query.

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If translation time is a concern, the class could be modified to have attach Connection and detach methods. The NamedParameterStatement could be created beforehand, attached to the connection, used and detached. However, the time taken to cache and synchronize, if necessary these objects would probably exceed the time needed to create new ones. A test of the above queries on my computer against a small table gave times of microseconds for NamedParameterStatement, microseconds for AttachableNamedParameterStatement without synchronizationand microseconds for a raw PreparedStatement.

Translating a query took approximately 6 microseconds. Benchmarking Java code is notoriously difficult because of garbage collection, just-in-time compilation, etc. In general, performance is not a concern, especially if the actual query is doing anything significant.

NamedParameterStatement is effective as a drop-in replacement for PreparedStatement with no configuration necessary. Programmer productivity can be boosted by the easier interface offered by the new class.

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Perhaps even more importantly, maintenance is easier because code is more readable. Problems with PreparedStatement syntax The problems with PreparedStatement stem from its syntax for parameters. Performance The time spent translating the query and looking up parameter indices is actually minimal compared to the time it takes to execute the query. Conclusion NamedParameterStatement is effective as a drop-in replacement for PreparedStatement with no configuration necessary.

Code import java.

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Connection; import java. PreparedStatement; import java. ResultSet; import java. SQLException; import java.So if we need to execute a database query with IN clause, we need to look for some alternative approach.

The aim of this post is to analyze different approaches and you can choose the one that suits your requirements. This is the simplest approach.

We can get the input and execute single PreparedStatement query multiple times. A sample program with this approach will look like below. This will result in ResultSet objects that will overload the system and it will also cause performance hit.

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So this approach is not recommended. We can write a stored procedure and send the input data to the stored procedure. Then we can execute queries one by one in the stored procedure and get the results. This approach gives fastest performance but as we all know that Stored Procedures are database specific.

So if our application deals with multiple types of databases such as Oracle, MySQL then it will become hard to maintain. We should use this approach only when we are working on single type of database and there is no plan to change the database server. Since writing stored procedure is out of scope of this tutorial, I will not demonstrate how to use it.

This approach involves writing logic to create the PreparedStatement query dynamically based on the size of the elements in IN clause. A simple example showing how to use it will look like below code.

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Notice that the query is created dynamically and it will run perfectly. There will be only one database call and the performance will be good. If you are not worried about PreparedStatement caching and there are not many queries with IN clause, then it seems to be the way to go. Suppose that the maximum allowed parameters in the query is 10, then we can write our logic like below. Notice that above program is using same PreparedStatement query for executing IN clause statement and will get the benefit of query caching and executing plan.

For simplicity, I am just returning if the number of input parameters is greater than the parameters size in the query but we can easily extend it to execute in batches to allow any number of inputs.

You can use any one of these based on your project requirements. How would you deal with it?By using our site, you acknowledge that you have read and understand our Cookie PolicyPrivacy Policyand our Terms of Service.

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If this in-clause can hold multiple values how can I do it. Sometimes I know the list of parameters beforehand or sometimes I don't know beforehand. How to handle this case? It explains the pros and cons of different methods of creating PreparedStatement with in clause.

An obvious approach is to dynamically generate the '? You can't replace? To support an arbitrary number of values, you'll have to dynamically build a string containing?

In my case it didn't worked, as the UUID Datatype in postgres seems to still have its weak spots, but for the usual types it works. Your database and the driver needs to support this! I tried Postgres 9. You need a jdbc 4 driver, otherwise setArray won't be available. I used the postgresql 9. What you can do is dynamically build the select string the 'IN? You can then instantiate the PreparedStatement. Currently, MySQL doesn't allow to set multiple values in one method call. So you have to have it under your own control.

I usually create one prepared statement for predefined number of parameters, then I add as many batches as I need. If you don't like to set NULL when no more parameters left, you can modify code to build two queries and two prepared statements.

First one is the same, but second statement for the remainder modulus. In this particular example that would be one query for 10 params and one for 8 params.

You will have to add 3 batches for the first query first 30 params then one batch for the second query 8 params. You don't want use PreparedStatment with dynamic queries using IN clause at least your sure you're always under 5 variable or a small value like that but even like that I think it's a bad idea not terrible, but bad.

As the number of elements is large, it will be worse and terrible.


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