CODEWITHSUNDEEP
springhibernatehql
Ben
Ben

Reputation: 62394

Is it possible to query the join table using HQL?

My Database:

WorkflowProcess
id | name

WorkflowProcessToWorkflowProcess
ancestor | descendent

I need to query for root WorkflowProcess. With this table structure, I'm looking to query something like SELECT * FROM WorkflowProcess WHERE id NOT IN (SELECT DISTINCT descendent FROM WorkflowProcessToWorkflowProcess)

My WorkflowProcess entity:

private Collection<WorkflowProcessEntity> workflowProcesses;

@JoinTable(name = "Workflow_Process_to_Workflow_Process", joinColumns = {
        @JoinColumn(name = "ancestor", referencedColumnName = "id")}, inverseJoinColumns = {
        @JoinColumn(name = "descendent", referencedColumnName = "id")})
@ManyToMany()
public Collection<WorkflowProcessEntity> getWorkflowProcesses() {
    return workflowProcesses;
}

public void setWorkflowProcesses(Collection<WorkflowProcessEntity> workflowProcesses) {
    this.workflowProcesses = workflowProcesses;
}

Is it possible to accomplish this with HQL?

Upvotes: 0

Views: 213

Answers (1)

axtavt
axtavt

Reputation: 242696

Try something like this:

select child 
from WorkflowProcess parent right join parent.workflowProcesses child 
where parent is null

Upvotes: 1

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