Custom Result handling by calling store procedure in Spring Data JPA - spring

Question

I have requirement to call store procedures which takes input parameters. This store procedure returns custom result set, that result set i need to read and process further before return to UI. How we can achieve this?
EG:
#Query("CALL SP_EMPLOYEE_REPORT(:year)",nativeQuery = true)
List<EmpolypeeCustomReportBean> getEmployeeReport(#param("year") Integer year);

Answer 1

Given the following stored procedure.
CREATE PROCEDURE NAME_OF_THE_PROCEDURE(IN param VARCHAR(255), OUT retval INT)
You can call it from interface query:
#Procedure(value = "NAME_OF_THE_PROCEDURE")
int getFromStoredProcedure(String param);
Also by #Query annotation:
#Query(value = "CALL NAME_OF_THE_PROCEDURE(:input_value);", nativeQuery = true)
Integer findSomeThing(#Param("input_value") Integer name);
Or you can use named stored procedure query too.
#Entity
#NamedStoredProcedureQuery(name = "MyObj.getSomethingFromProc",
procedureName = "NAME_OF_THE_PROCEDURE", parameters = {
#StoredProcedureParameter(mode = ParameterMode.IN, name = "param", type = String.class),
#StoredProcedureParameter(mode = ParameterMode.OUT, name = "retval", type = Integer.class)})
public class MyObj{
// class definition
}
Then call it.
#Procedure(name = "MyObj.getSomethingFromProc")
Integer getSomethingFromStoredProc(#Param("param") String model);
Also you can use resultClasses and resultSetMapping properties in #NamedStoredProcedureQuery for complex return types.
Complex example provided by Eclipselink:
#NamedStoredProcedureQuery(
name="ReadUsingMultipleResultSetMappings",
procedureName="Read_Multiple_Result_Sets",
resultSetMappings={"EmployeeResultSetMapping", "AddressResultSetMapping", "ProjectResultSetMapping", "EmployeeConstructorResultSetMapping"}
)
#SqlResultSetMappings({
#SqlResultSetMapping(
name = "EmployeeResultSetMapping",
entities = {
#EntityResult(entityClass = Employee.class)
}
),
#SqlResultSetMapping(
name = "EmployeeConstructorResultSetMapping",
classes = {
#ConstructorResult(
targetClass = EmployeeDetails.class,
columns = {
#ColumnResult(name="EMP_ID", type=Integer.class),
#ColumnResult(name="F_NAME", type=String.class),
#ColumnResult(name="L_NAME", type=String.class),
#ColumnResult(name="R_COUNT", type=Integer.class)
}
)
}
)
})
public Employee(){
....
}