when trying to search with single record then this query works
#Query(value = "select * from table t where t.column1 = :column1 and t.column2 = :column2 and t.column3 = :column3")
Flux<Invoice> findByMultipleColumn(#Param("column1”) String column1, #Param("column2”) String column2, #Param("column3”) String column3);
But when I have list of criterias instead of a single row condition then I have to loop over the list of criterias & call the above query multiple times which is not feasible solution.
Sudo code
for (Criteria criteria : criteriaList) {
repository.findByMultipleColumn(criteria.getColumn1(), criteria.getColumn2(), criteria.getColumn3());
}
What I am trying to find a way to solve the above query for multiple LIST of all the 3 column criteria pair, something like below (this is not working solution)
#Query(value = "select * from table t where t.column1 = :column1 and t.column2 = :column2 and t.column3 = :column3")
Flux<Invoice> findByMultipleColumn(#Param List<Table> table);
Is there any way somehow we can try to achieve the above case?
Would be doable if column1, 2 and 3 were Embedded, then you could do
#Query(select * from Entity where embeddedProperty in (:values))
Flux<Entity> findByEmbeddedPropertyIn(Collection<EmbeddedClas> values);
Which would generate the following native SQL clause
Where (column1, column2, column3) in ((x, y, z), ...)
If you don't want to pack these fields i to an embeddable class, you can also try to do a workaround
#Query(select * from Entity where Concat(column1, ';', column2, ';', column3) in (:parametersConcatrenatedInJava)
Flux<Entity> findBy3Columns(Collection<String> parametersConcatrenatedInJava);
It's ofcourse not bulletproof, all three columns could have ";" as their values, this might be problematic if their type is not string, etc.
Edit.:
Third option is to use specification api. Using the criteria builder you can concatenate multiple and / or queries. And pass that specification as an argument to the repository that extends JpaSpecificationExecutor (if you're fetching whole entities) or an entity manager if you're using projections. Read more about specifications
Related
I have two tables
table1
id|name|next_field
table2
id|id_of_table1|whatelse
I do a msql query to get all entries of table1 and the number of entries in table2 who has table2.id_of_table1 = table1.id
This is my query - it works fine.
$select =array('table1.*', 'COUNT(table2.id) AS `my_count_result`',);
$this->db->select($select);
if($id!=false){ $this->db->where('id',$id); }
$this->db->from('table1 as t1');
$this->db->join('table2 as t2', 't1.id = t2.id_of_table1');
return $this->db->get()->result_array();
Now I have another field which has coma-separated data
table1.next_field = info1, info2, next,...
Now I want to check in the same way like the first query how often for example "info2" is as a part inside the table1.next_field
Is it possible, how?
After all i decide to change my database structure to make the work and handle much easier.
this is my native SELECT Query in Repository
#Modifying
#Query(value = "SELECT * FROM tasks WHERE title LIKE '%Java%' ORDER BY id DESC ", nativeQuery = true)
List<Task> listAllTasks();
this works ok, but when I use custom column name instead of *, like this
#Modifying
#Query(value = "SELECT title FROM tasks WHERE title LIKE '%Java%' ORDER BY id DESC ", nativeQuery = true)
List<Task> listAllTasks();
I have this error :
org.postgresql.util.PSQLException: The column name id was not found in this ResultSet.
any Help?
The resultset doesn't have the "id" in it, you have to provide it.
You should change the way you are declaring your SQL:
SELECT t.title, t.id FROM tasks t WHERE t.title LIKE '%Java%' ORDER BY t.id DESC
Check out this sort example:Native Queries
Select * from Entity -> returns a List of Entity
Example:
#Query(select * from tasks)
List<Task> findAllTasks();
Select column from Entity -> returns a List of Types of the entity.
Example:
#Query(select t.title from tasks t)
List<String> findTitle_AllTasks();
title is of the type String
Select multiple columns from Entity -> returns an Object[] holding the data
Example:
#Query(select t.id, t.title from tasks t)
List<Object[]> findIdTitle_AllTasks();
So, you are retrieving String type data - title and asking to return a List of Task type. This is causing the problem. You can actually check the hibernate docs under HQL and JPQL to understand this.
Plus, you are doing a SELECT (DQL operation). #Modifying is rudimentary here as it is used for DML operations using Data JPA - UPDATE/DELETE.
I have the following query where the first argument itself is a subquery
The java code is:
String query = select * from (?) where ROWNUM < ?
PreparedStatement statement = conn.preparedStatement(query)
statement.setString(1, "select * from foo_table")
statement.setInt(2, 3)
When I run the java code, I get an exception. What alternatives do I have for making the first subquery statement.setString(1, "select * from foo_table") a parameter?
This is not possible, parameter placeholders can only represent values, not object names (like table names, column names, etc) nor subselects or other query elements.
You will need to dynamically create the query to execute using string concatenation, or other string formatting/templating options.
How can I achieve this functionality from SQL in LINQ?
Here I am getting 3 SP Number to one Contract ID:
DECLARE #Names VARCHAR(8000)
SELECT #Names = COALESCE( #Names + ', ', '') + us.SP_NBR
FROM CAATS_ADMIN.CONTRACT_SP us
WHERE US.CNTRCT_ID='1000038'
You can use the LINQ aggregate function. You will need to retrieve the data in a SELECT to a list of strings through whatever data access mechanism you are using then you use the Aggregate like this:
List<string> source = GetMyData();
var b = source.Aggregate ("",
(current, s)=> string.Concat(current, string.Format("{0},", s)) );
This applies the string concatenation to every item in the sequence to build a single string.
I'm trying to implement https://stackoverflow.com/a/16392399/14731 for a table called "Modules" using QueryDSL. Here is my query:
String newName = "MyModule";
QModules modules = QModules.modules;
BooleanExpression moduleNotExists = session.subQuery().
from(modules).where(modules.name.eq(newName)).notExists();
SimpleSubQuery<String> setModuleName = session.subQuery().
where(moduleNotExists).unique(Expressions.constant(newName));
long moduleId = session.insert(modules).set(modules.name, setModuleName).
executeWithKey(modules.id);
I am expecting this to translate into:
insert into modules(name)
select 'MyModule'
where not exists
(select 1 from modules where modules.name = 'MyModule')
Instead, I am getting:
NULL not allowed for column "NAME"; SQL statement:
insert into MODULES (NAME)
values ((select ?
from dual
where not exists (select 1
from MODULES MODULES
where MODULES.NAME = ?)))
where ? is equal to MyModule.
Why does QueryDSL insert from dual? I am expecting it to omit from altogether.
How do I fix this query?
For the insert into select form use
columns(...).select(...)
But your error suggests that the INSERT clause is valid, but semantically not what you want.
Using InsertClause.set(...) you don't get the conditional insertion you are aiming for.
In other words with
columns(...).select(...)
you map the full result set into an INSERT template and no rows will be inserted for empty result sets, but with
set(...)
you map query results to a single column of an INSERT template and null values will be used for empty results.