Dynamic bind select values in MySQL query jdbi - java

How can i write dynamic SQL query in Jbdi, like in my project customer will ask some details like first name,last name,mobile. so i will read those values into string and my idea was directly append that to SQL query dynamically like
select first name,last name,mobile from customer
and another user ask only first name then my query will change like
select first name from customer where customer Id=12345

I am doing something similar for dynamically generated search criteria strings in a Dropwizard application using JDBI.
#UseStringTemplate3StatementLocator
public interface ThingieDao {
#SqlQuery
#MapResultAsBean
Iterator<Thingie> search(#Define("criteria") String criteria);
}
The defined string "criteria" can then be used in the SQL template:
group ThingieDao;
search(criteria) ::= <<
SELECT * FROM table_name WHERE <criteria>
>>
You can use the same technique to insert any string in the SQL, the SELECT column names in your case.
The variable name in the interface does not matter, it is the #Define annotation string that matters.. Assuming Dropwizard doesn't add anything magic, and it usually doesn't, I guess that should work using plain JDBI as well.

Related

How to generate SQL from template with order by parameter using jOOQ?

I generate the SQL template like this with jOOQ 3.11.11.
DSLContext context = new DefaultDSLContext(conf);
Query query = context.select()
.from("table1")
.where(DSL.field("report_date").eq(DSL.param("bizdate")))
.orderBy(DSL.param("sort"));
String sqlTemp = context.renderNamedParams(query);
SQL template:
select *
from table1
where report_date = :bizdate
order by :sort
The SQL template is stored and the params are decided at realtime query condition.
ResultQuery resultQuery = context.resultQuery(sqlTemp, DSL.param("bizdate", "20190801"), DSL.param("sort", "id desc"));
The realtime SQL:
select *
from table1
where report_date = '20190801'
order by 'id desc'
There is something wrong with the order by clause.
So. How to replace the order by param sort with "id desc" or "name asc" and eliminate the quotes?
DSL.param() creates a bind variable, which is generated as ? in SQL, or :bizdate if you choose to use named parameters, or '20190801' if you choose to inline the bind variables. More about bind variables can be seen here.
You cannot use DSL.param() to generate column references or keywords. A column expression (e.g. a reference) is described in the jOOQ expression tree by the Field type. Keywords are described by the Keyword type, but you probably do not want to go this low level. Instead you want to handle some of the logic in your query expression. For example:
String sortField = "id";
SortOrder sortOrder = SortOrder.ASC;
Query query = context.select()
.from("table1")
.where(DSL.field("report_date").eq(DSL.param("bizdate")))
.orderBy(DSL.field(sortField).sort(sortOrder));
The mistake you're making is to think that you can use a single SQL template for all sorts of different dynamic SQL queries, but what if you're dynamically adding another predicate? Or another join? Or another column? You'd have to build a different jOOQ expression tree anyway. Just like here. You could store two SQL strings (one for each sort order), and repeat that for each sort column.
But, instead of pre-generating a single SQL string, I recommend you extract a function that takes the input parameters and generates the query every time afresh, e.g.:
ResultQuery<?> query(String bizDate, Field<?> sortField, SortOrder sortOrder) {
return context.selectFrom("table1")
.where(field("report_date").eq(bizDate))
.orderBy(sortField.sort(sortOrder));
}
Here is some further reading about using jOOQ for dynamic SQL:
https://www.jooq.org/doc/latest/manual/sql-building/dynamic-sql
https://blog.jooq.org/2017/01/16/a-functional-programming-approach-to-dynamic-sql-with-jooq

Hibernate exception on encountering mysql := operator

When I execute the following code the exception occurs:
Exception: org.springframework.orm.hibernate3.HibernateQueryException:
Not all named parameters have been set
Here is my code:
queryString = SET #quot=0,#latest=0,#comp='';
select B.* from (
select A.time,A.change,IF(#comp<>A.company,1,0) as LATEST,#comp:=A.company as company from (
select time,company,quote-#quot as `change`, #quot:=quote curr_quote
from stocks order by company,time) A
order by company,time desc) B where B.LATEST=1;
list = getHibernateTemplate().executeFind(new HibernateCallback(){
public Object doInHibernate(Session session)throws HibernateException,SQLException {
SQLQuery query = session.createSQLQuery(queryString);
query.setParameterList("list", custIds);
return query.list();
}
What is the reason for this behavior?
It's a little bit hard to understand, what is exactly the query you are executing, but if you need to use the colon character in native query, in your case as "assign a value" operator, you should escape all the colon occurances with \\ in your java String with the query, so it could be like:
select B.* from (
select A.time,A.change,IF(#comp<>A.company,1,0) as LATEST,#comp\\:=A.company as company from (
select time,company,quote-#quot as `change`, #quot\\:=quote curr_quote
from stocks order by company,time) A
order by company,time desc) B where B.LATEST=1;
Update: seems, it is not possible yet to escape the colons in Hibernate native queries, there is an open issue about it. That means, that you are not able to use a colons in Hibernate native queries not for the named parameters. You can try to create a function and call it instead of calling a query.
you can create a named query and then use it in spring jpa repository or hibernate. This link helped me from similar problem.

jpql left join fetch not returning results for like

In a spring mvc app using hibernate and MySQL, I have written the following query method to return a list of names with patients:
#SuppressWarnings("unchecked")
public Collection<Person> findPersonByLastName(String ln) throws DataAccessException{
Query query = this.em.createQuery("SELECT DISTINCT pers FROM rimPerson pers left join fetch pers.names nm WHERE nm.family LIKE :lnm");
query.setParameter("lnm", ln);
return query.getResultList();
}
This is producing the following hibernate sql:
Hibernate:
select distinct
person0_.hppid as hppid1_340_0_,
names1_.HJID as HJID1_89_1_,
person0_2_.classCode_HJID as classCod2_339_0_,
person0_1_.administrativeGenderCode_HJID as administ2_341_0_,
person0_1_.birthTime_HJID as birthTim3_341_0_,
names1_.DELIMITER_ as DELIMITE2_89_1_,
names1_.FAMILY as FAMILY3_89_1_,
names1_.named_entity_hppid as named5_89_1_,
names1_.SUFFIX as SUFFIX4_89_1_,
names1_.name_entity_HJID as name9_340_0__,
names1_.HJID as HJID1_89_0__
from
rim_person person0_ inner join rim_living_subject person0_1_ on person0_.hppid=person0_1_.hppid
inner join rim_entity person0_2_ on person0_.hppid=person0_2_.hppid
inner join rim_infrastructure_root person0_3_ on person0_.hppid=person0_3_.hppid
left outer join EN names1_ on person0_.hppid=names1_.name_entity_HJID
where names1_.FAMILY like ?
When I call the above jpql method with the following command, it returns zero results:
this.myappService.findPersonByLastName("");
I also get zero results when I cut and past the above generated hibernate code into the MySQL command line client and replace ? with ''.
If, however, I remove the where names1_.FAMILY like ? from the hibernate generated sql above and place the shortened sql into the MySQL command line client, I get four results, eachof which has a value for the lastname field.
How can I change the jpql so that it generates a hibernate query that returns the four results when `` is passed as the empty string parameter? I want the result set to include every result when the user gives empty input, but to give filtered results when the user types in any given text input.
The typical reason that like fails to do what you think it ought to do is to forget to put a wildcard in the pattern string. For example, if you want to match all user names that begin with 'Code' you must do something like name like 'Code%', NOT name like 'Code'. You can control exactly what your predicate matches with careful placement of %s in your string.
Try this to see all entities no matter what the value in family:
this.myappService.findPersonByLastName("%");
It is kinda cheesy to have the caller of findPersionByLastName have to put in the % wildcard. A better implementation is to have the caller specify which last name they are looking for, and then have the code that constructs the query put the wildcard in the right place. When you are looking for last names, you might do something like this:
query.setParameter("lnm", "%" + ln);
That would match anything that ends with the parameter that is passed to the method.

How to prevent query injection on Google Big Query

I'm writing some Google Big-query dynamic reporting utilities to our website, that will allow users to select a parameter to be replaced in the query. Given this query "template":
SELECT name ,
birthday
FROM [dataset.users]
WHERE registration_date = '{{registration_date}}'
we take the {{registration_date}} value from the user and replace it in the template, resulting in a query:
SELECT name ,
birthday
FROM [dataset.users]
WHERE registration_date = '2013-11-11'
How I can prevent sql-injection like attacks in this scenario, given that I'm executing the queries using the Google Big-query client API,
and the API don't allow one to use positioned parameters as on traditional RDBMS apis.
Since the launch of standard SQL in BigQuery, it has been possible to use query parameters as a way of preventing SQL injection. In your query, you can specify named parameters using # followed by a name, e.g.
SELECT x, y FROM T WHERE x <= #x_max AND y = #target_y;
You can then provide the parameter values through the query_parameters attribute of the API.
Check "Defense Option 3: Escaping All User Supplied Input" in OWASP:
https://www.owasp.org/index.php/SQL_Injection_Prevention_Cheat_Sheet#Defense_Option_3:_Escaping_All_User_Supplied_Input
UPDATE: Parametrized queries are an option now
https://cloud.google.com/bigquery/docs/parameterized-queries

How to Manipulate SQL specified in jrxml template

Problem: Report Templates are created by Admin Users who only decide what data to show where as the filter for the data is specified by the business user. In simpler SQL terms, query is specified by the Admin User, Business User specifies the WHERE clause.
Jasper allows user to specify parameters in SQL query like $P{city}. I have tried to retrieve the query dynamically using the method specfied in the link.
Possible Solution can be
Use WHERE clause parameters in JRXML and replace them while report creation - This will save me SQL parsing but I don't want to guide the admin user with this complexity. Parsing is not a huge problem.
Use my custom jdbc query executor and factory, only created to allow me extension point before jasper fire SQL query. I will be completely relying on vanilla Jasper JDBC data source but will only modify query before execution. JRAbstractQueryExecuter simplifies the query and replace the jasper related tokens before firing query - This will be very dirty and will force me to be implementation specific.
Do the same replacement as it is done in JRAbstractQueryExecuter in my application code base, parse the SQL query, modify it and set it again as specified in link
Can you please suggest a better way of doing this? I have a feeling that this can definitly be done in cleaner way.
Thanks for your help
You could create an input control to determine the desired WHERE clause and use a parameter to hold the contents of that WHERE clause. The default value expression would be something like:
$P{theParameter} == "value_1" ?
(" AND CONDITION_1 IN ('A', 'B', 'C') AND CONDITION_2 = 'Yes' "
) : " AND CONDITION_3 = 'Other' AND CONDITION_4 = 'No' "
Then in your WHERE clause you would reference it like:
WHERE
.... = .....
AND .... = ....
AND .... = ....
$P!{theParameter}
If your constraint columns are the same across your WHERE clauses, you could use $P! to bring in the parameter value literally, and reference it in your query:
WHERE
.... = .....
AND .... = ....
AND .... = ....
AND thisValue = $P!{theParameter}

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