Related
I don't understand this error, I have two entities Task and Project, one task is assign to one project (see code below).
But when I want test to add a task, I have this error:
android.database.sqlite.SQLiteConstraintException: FOREIGN KEY constraint failed (code 787 SQLITE_CONSTRAINT_FOREIGNKEY)
I try to add onDelete = CASCADE to FOREIGNKEY but my test does not work :/
Task Class
#Entity(tableName = "task_table",
foreignKeys = #ForeignKey(entity = Project.class,
parentColumns = "id",
childColumns = "projectId"))
public class Task {
/**
* The unique identifier of the task
*/
#PrimaryKey(autoGenerate = true)
public long id;
private long projectId;
#SuppressWarnings("NullableProblems")
#NonNull
private String name.
private long creationTimestamp;
public Task(long projectId, #NonNull String name, long creationTimestamp) {
this.setProjectId(projectId);
this.setName(name);
this.setCreationTimestamp(creationTimestamp);
}
...
TaskDao
#Dao
public interface TaskDao {
#Insert(onConflict = OnConflictStrategy.REPLACE)
void insert(Task task);
#Query("DELETE FROM task_table WHERE id = :id")
void delete(long id);
#Query("SELECT * FROM task_table ORDER BY id ASC")
LiveData<List<Task>> getAllTasks();
#Query("SELECT * FROM task_table WHERE id = :id")
LiveData<Task> getTaskById(long id);
}
Project Class
#Entity(tableName = "project_table")
public class Project {
/**
* The unique identifier of the project
*/
#PrimaryKey(autoGenerate = true)
public long id;
#NonNull
private String name;
#ColorInt
private int color;
public Project(#NonNull String name, #ColorInt int color) {
this.name = name;
this.color = color;
}
ProjectDao
#Dao
public interface ProjectDao {
#Insert(onConflict = OnConflictStrategy.IGNORE)
void insert(Project project);
#Insert(onConflict = OnConflictStrategy.REPLACE)
void insertAll(List<Project> projects);
#Query("SELECT * FROM project_table")
LiveData<List<Project>> getAllProjects();
#Query("SELECT * FROM project_table WHERE id = :id")
LiveData<Project> getProjectById(long id);
}
TestInstrumented:
#Before
public void createDb() {
this.database = Room.inMemoryDatabaseBuilder(ApplicationProvider.getApplicationContext(),
AppDatabase.class)
.allowMainThreadQueries()
.build();
taskDao = database.taskDao();
projectDao = database.projectDao();
}
#After
public void closeDb() {
database.close();
}
#Test
public void addTask() {
Project project = new Project("toto", 0xFFB4CDBA);
this.projectDao.insert(project);
long projectId = project.getId();
assertThat(projectId, equalTo(project.getId()));
Task task = new Task(projectId, "tâche 1", new Date().getTime());
this.taskDao.insert(task);
}
If someone can help it'll be very kind, I don't know how I can resolve this.
Thanks very much for your help
The project id will be 0 as it hasn't been set according to the inserted value when you use long projectId = project.getId();.
Thus the ForeignKey conflict when inserting the Task as the id column of the project will have been generated by SQLite and WILL not be 0 (it will be 1 or greater).
Change
#Insert(onConflict = OnConflictStrategy.IGNORE)
void insert(Project project);
to (to get the actual generated id)
#Insert(onConflict = OnConflictStrategy.IGNORE)
long insert(Project project); // will return the id that has been generated
and then use :-
Project project = new Project("toto", 0xFFB4CDBA);
long projectId = this.projectDao.insert(project); //<<<<< returns the actual id
project.setId(projectId); // sets project id according to the inserted id BUT only if inserted and not ignored when returned value will be -1
// You should really check for -1 and handle accordingly
assertThat(projectId, equalTo(project.getId())); // not really of any use
Task task = new Task(projectId, "tâche 1", new Date().getTime());
this.taskDao.insert(task);
Note, the above is in-principle code, it has not been compiled or run/tested. It may therefore contain some errors.
This is my first time asking a question here in StackOverflow so forgive me if I am not asking the question right or a certain way.
I have two child classes (PerformanceAssessment and ObjectiveAssessment) from parent class Assessment. I was able to successfully do downcasting for the polymorphism part requirement of my school project, and I was able to save to their appropriate databases both instances of parent and child after downcasting (I have an assessment_table, performance_assessments, and objective_assessments table). However, I am now having Android Room database issues. I realized that I need to implement foreign keys to do the CRUD operations properly. How do I tweak my parent and child classes code and add proper annotations for implementing foreign and primary keys correctly? I need to have an autogenerated primary key for each class: parent (Assessment) and both children (PerformanceAssessment and ObjectiveAssessment). But I also need to utilize the children's primary key as a foreign key for the parent's databases so that when I delete an instance of Performance/Objective assessments, I can also delete the Assessment instance when I am downcasting. I found very little helpful information regarding this. Thanks in advance.
I am getting these errors right now:
Build Errors
Parent Class: Assessment.java
#Entity(tableName = "assessment_table")
public class Assessment {
#PrimaryKey(autoGenerate = true)
#ColumnInfo(name = "assessment_id")
private final int assessment_id;
private String assessmentName;
private String assessmentStart;
private String assessmentEnd;
private int courseID;
public Assessment(int assessment_id, String assessmentName, String assessmentStart, String assessmentEnd, int courseID) {
this.assessment_id = assessment_id;
this.assessmentName = assessmentName;
this.assessmentStart = assessmentStart;
this.assessmentEnd = assessmentEnd;
this.courseID = courseID;
}
Child class: PerformanceAssessment.java
#Entity(tableName = "performance_assessment", foreignKeys = {
#ForeignKey(
entity = Assessment.class,
parentColumns = "assessment_id",
childColumns = "performance_id",
onUpdate = CASCADE,
onDelete = CASCADE
)
})
public class PerformanceAssessment extends Assessment{
#PrimaryKey(autoGenerate = true)
#ColumnInfo(name = "performance_id")
private int performanceID;
private String type;
public PerformanceAssessment(int assessment_id, String assessmentName, String assessmentStart, String assessmentEnd, int courseID, int performanceID, String type) {
super(assessment_id, assessmentName, assessmentStart, assessmentEnd, courseID);
this.performanceID = performanceID;
this.type = type;
}
Child class: ObjectiveAssessment.java
#Entity(tableName = "objective_assessment", foreignKeys = {
#ForeignKey(
entity = Assessment.class,
parentColumns = "assessment_id",
childColumns = "objective_id",
onUpdate = CASCADE,
onDelete = CASCADE
)
})
public class ObjectiveAssessment extends Assessment{
#PrimaryKey(autoGenerate = true)
#ColumnInfo(name = "objective_id")
private int objective_ID;
private String type;
public ObjectiveAssessment(int assessmentID, String assessmentName, String assessmentStart, String assessmentEnd, int courseID, int objective_ID, String type) {
super(assessmentID, assessmentName, assessmentStart, assessmentEnd, courseID);
this.objective_ID = objective_ID;
this.type = type;
}
Here is the part where I am adding a new assessment in the app:
public void saveAssessment(View view) {
assessmentTitle = editName.getText().toString();
assessmentStart = editStart.getText().toString();
assessmentEnd = editEnd.getText().toString();
//Check if fields are empty:
if (assessmentTitle.isEmpty() || assessmentStart.isEmpty() || assessmentEnd.isEmpty()) {
Toast.makeText(AddAssessmentScreen.this, "Fill out required fields.", Toast.LENGTH_LONG).show();
return;
}
else {
//Check assessment type selected (used Downcasting for polymorphism):
if (assessment_type == true) {
Assessment performanceAssessment = new PerformanceAssessment(0, assessmentTitle, assessmentStart, assessmentEnd, currentCourseID, 0, selectedString);
PerformanceAssessment castedPerformance = (PerformanceAssessment) performanceAssessment;
//Insert assessment to database performance_assessment table (Performance child type):
repository.insert(castedPerformance);
Repository addToAssessment = new Repository(getApplication());
//Insert assessment to database assessment_table (Assessment parent type):
addToAssessment.insert(performanceAssessment);
}
else {
Assessment objectiveAssessment = new ObjectiveAssessment(0,assessmentTitle, assessmentStart, assessmentEnd, currentCourseID, 0, selectedString);
ObjectiveAssessment castedObjective = (ObjectiveAssessment) objectiveAssessment;
//Insert assessment to database objective_assessment table (Objective child type):
repository.insert(castedObjective);
Repository addToAssessment = new Repository(getApplication());
//Insert assessment to database assessment_table (Assessment parent type):
addToAssessment.insert(objectiveAssessment);
}
Toast.makeText(AddAssessmentScreen.this, "New assessment added. Refresh previous screen.", Toast.LENGTH_LONG).show();
}
How do I tweak my parent and child classes code and add proper annotations for implementing foreign and primary keys correctly?
Let the assessment_id always be the primary key i.e. don't code it in sub classes and then have a field for the reference/map/association with the parent in the subclasses.
So PerformanceAssessment could be :-
#Entity(tableName = "performance_assessment", foreignKeys = {
#ForeignKey(
entity = Assessment.class,
parentColumns = "assessment_id",
childColumns = "assessment_reference",
onUpdate = CASCADE,
onDelete = CASCADE
)
})
public class PerformanceAssessment extends Assessment {
private int assessment_reference; //<<<<<<<<<
private String type;
public PerformanceAssessment(int assessment_id, String assessmentName, String assessmentStart, String assessmentEnd, int courseID, int assessment_reference, String type) {
super(assessment_id, assessmentName, assessmentStart, assessmentEnd, courseID);
this.assessment_reference = assessment_reference;
this.type = type;
}
....
and all compiles and the underlying tables will be build using :-
_db.execSQL("CREATE TABLE IF NOT EXISTS `assessment_table` (`assessment_id` INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL, `assessmentName` TEXT, `assessmentStart` TEXT, `assessmentEnd` TEXT, `courseID` INTEGER NOT NULL)");
_db.execSQL("CREATE TABLE IF NOT EXISTS `performance_assessment` (`assessment_reference` INTEGER NOT NULL, `type` TEXT, `assessment_id` INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL, `assessmentName` TEXT, `assessmentStart` TEXT, `assessmentEnd` TEXT, `courseID` INTEGER NOT NULL, FOREIGN KEY(`assessment_reference`) REFERENCES `assessment_table`(`assessment_id`) ON UPDATE CASCADE ON DELETE CASCADE )");
Obviously similar for the ObjectiveAssessment.
But I also need to utilize the children's primary key as a foreign key for the parent's databases so that when I delete an instance of Performance/Objective assessments, I can also delete the Assessment instance when I am downcasting.
What if, which is possible with the 1 (Assessment) - Many (PerformanceAssessments), an Assessment has multiple PerformanceAssesments? Deleting 1 PerformanceAsessment would delete the parent Assessment, which would then, due to the use of onDelete CASCADE cascade the deletions to all the other PerformanceAssessments and ObjectiveAssessments. Deletions are not propagated up to the parent (that's why the term CASCADE is used as it implies downward rather than anyway).
As an example you have an assessment with 4 PerformanceAssessments and lets say 3 ObjectiveAssessments one of the PerformanceAssesments was wrongly added. Should everything have to be deleted and re-entered to correct the 1 wrong PeformanceAssessment.
You could introduce a Trigger to automate this upwards propogation, to delete anything and delete all, if that is what you want.
Additional Re comments
I have a one to one relationship for the Assessment and Performance/Objective assessment. One assessment can only have either performance or objective type.
That may be what you wish BUT there is nothing stopping an Assessment having multiple Performance and or Objectives. That may or may not be an issue.
Also, instead of downcasting, I did upcasting instead on where I save the assessment in the app. I ran into Foreign Key Constraint Failed (code 787) and realized it was because I was downcasting. My only dilemma now is that whenever I am saving an assessment, it will only save on assessment_table and not on performance_assessment or objective_assessment tbl.
What you have to do is insert the Assessment (parent) and then use the parent's id to insert the related Peformance/Objective with the assessment_reference set the the value of the assessment.
The 787 is it saying that you cannot insert a child (Performance/Objective) without the assessment_reference being an assessment_id in the Assessment.
What you can do, which would very likely suit your situation is a) have an #Insert long insert(Assessment assessment); and an #Insert long (PerformanceAssessment performanceAssessment) (likewise for Objective)
and then use (assuming dao is an instance of the #Dao)
and use
dao.insert(new PerformanceAssessment(0,"the title", etc,dao.insert(Assessment(....),"the type");
So the Assessment is added as part of inserting the performance/Objective and with the id of the assessment being used as the assessment_reference value.
NOTE the #Insert will only return a long, so you have to convert this to an int. I would suggest changing id's and references to be long's. The overhead, if any, will have a minimal impact. Storage in the database will not be affected and it will save the hassle of converting long to int.
Demonstration
The following is a demonstration based upon code that closely reflects your but with some subtle changes.
id's have been changed to be long rather than int.
autogenerate has been removed BUT the id's will be generated as before.
2. All that autogenerate does from an SQLite standpoint is include the AUTOINCREMENT key word. This is actually inefficient and NOT recommended. https://sqlite.org/autoinc.html
So the code is :-
Assessment
#Entity(tableName = "assessment_table")
public class Assessment {
#PrimaryKey /* no need for autogenerate */
#ColumnInfo(name = "assessment_id")
/* As not autogenerate then use Long and default to null */
/* same as autogenerate but without the overheads/inefficiencies */
private Long assessment_id = null; //Long rather than long so can be null and have id generated.
private String assessmentName;
private String assessmentStart;
private String assessmentEnd;
private long courseID;
public Assessment(long assessment_id, String assessmentName, String assessmentStart, String assessmentEnd, long courseID) {
this.assessment_id = assessment_id;
this.assessmentName = assessmentName;
this.assessmentStart = assessmentStart;
this.assessmentEnd = assessmentEnd;
this.courseID = courseID;
}
#Ignore
/* Alternative constructor no need to provide id for inserting */
public Assessment(String assessmentName, String assessmentStart, String assessmentEnd, long courseID) {
this.assessmentName = assessmentName;
this.assessmentStart = assessmentStart;
this.assessmentEnd = assessmentEnd;
this.courseID = courseID;
}
public Long getAssessment_id() {
return assessment_id;
}
public void setAssessment_id(Long assessment_id) {
this.assessment_id = assessment_id;
}
public String getAssessmentName() {
return assessmentName;
}
public void setAssessmentName(String assessmentName) {
this.assessmentName = assessmentName;
}
public String getAssessmentStart() {
return assessmentStart;
}
public void setAssessmentStart(String assessmentStart) {
this.assessmentStart = assessmentStart;
}
public String getAssessmentEnd() {
return assessmentEnd;
}
public void setAssessmentEnd(String assessmentEnd) {
this.assessmentEnd = assessmentEnd;
}
public long getCourseID() {
return courseID;
}
public void setCourseID(long courseID) {
this.courseID = courseID;
}
}
PerformanceAssessment
#Entity(tableName = "performance_assessment", foreignKeys = {
#ForeignKey(
entity = Assessment.class,
parentColumns = "assessment_id",
childColumns = "assessment_reference",
onUpdate = CASCADE,
onDelete = CASCADE
)
})
public class PerformanceAssessment extends Assessment {
private long assessment_reference;
private String type;
public PerformanceAssessment(long assessment_id, String assessmentName, String assessmentStart, String assessmentEnd, long courseID, long assessment_reference, String type) {
super(assessment_id, assessmentName, assessmentStart, assessmentEnd, courseID);
this.assessment_reference = assessment_reference;
this.type = type;
}
#Ignore
public PerformanceAssessment(String assessmentName, String assessmentStart, String assessmentEnd, long courseID, long assessment_reference, String type) {
super(assessmentName, assessmentStart, assessmentEnd, courseID);
this.assessment_reference = assessment_reference;
this.type = type;
}
#Override
public Long getAssessment_id() {
return super.getAssessment_id();
}
#Override
public void setAssessment_id(Long assessment_id) {
super.setAssessment_id(assessment_id);
}
#Override
public String getAssessmentName() {
return super.getAssessmentName();
}
#Override
public void setAssessmentName(String assessmentName) {
super.setAssessmentName(assessmentName);
}
#Override
public String getAssessmentStart() {
return super.getAssessmentStart();
}
#Override
public void setAssessmentStart(String assessmentStart) {
super.setAssessmentStart(assessmentStart);
}
#Override
public String getAssessmentEnd() {
return super.getAssessmentEnd();
}
#Override
public void setAssessmentEnd(String assessmentEnd) {
super.setAssessmentEnd(assessmentEnd);
}
#Override
public long getCourseID() {
return super.getCourseID();
}
#Override
public void setCourseID(long courseID) {
super.setCourseID(courseID);
}
public long getAssessment_reference() {
return assessment_reference;
}
public void setAssessment_reference(long assessment_reference) {
this.assessment_reference = assessment_reference;
}
public String getType() {
return type;
}
public void setType(String type) {
this.type = type;
}
}
ObjectiveAssessment
#Entity(tableName = "objective_assessment", foreignKeys = {
#ForeignKey(
entity = Assessment.class,
parentColumns = "assessment_id",
childColumns = "assessment_reference",
onUpdate = CASCADE,
onDelete = CASCADE
)
})
public class ObjectiveAssessment extends Assessment {
private long assessment_reference;
private String type;
public ObjectiveAssessment(long assessment_id, String assessmentName, String assessmentStart, String assessmentEnd, long courseID, long assessment_reference, String type) {
super(assessment_id, assessmentName, assessmentStart, assessmentEnd, courseID);
this.assessment_reference = assessment_reference;
this.type = type;
}
#Ignore
public ObjectiveAssessment(String assessmentName, String assessmentStart, String assessmentEnd, long courseID, long assessment_reference, String type) {
super(assessmentName, assessmentStart, assessmentEnd, courseID);
this.assessment_reference = assessment_reference;
this.type = type;
}
#Override
public Long getAssessment_id() {
return super.getAssessment_id();
}
#Override
public void setAssessment_id(Long assessment_id) {
super.setAssessment_id(assessment_id);
}
#Override
public String getAssessmentName() {
return super.getAssessmentName();
}
#Override
public void setAssessmentName(String assessmentName) {
super.setAssessmentName(assessmentName);
}
#Override
public String getAssessmentStart() {
return super.getAssessmentStart();
}
#Override
public void setAssessmentStart(String assessmentStart) {
super.setAssessmentStart(assessmentStart);
}
#Override
public String getAssessmentEnd() {
return super.getAssessmentEnd();
}
#Override
public void setAssessmentEnd(String assessmentEnd) {
super.setAssessmentEnd(assessmentEnd);
}
#Override
public long getCourseID() {
return super.getCourseID();
}
#Override
public void setCourseID(long courseID) {
super.setCourseID(courseID);
}
public long getAssessment_reference() {
return assessment_reference;
}
public void setAssessment_reference(long assessment_reference) {
this.assessment_reference = assessment_reference;
}
public String getType() {
return type;
}
public void setType(String type) {
this.type = type;
}
}
A POJO has the Assessment Embedded and the Perf and Obj included via #Relation (not the ideal as if the rule of only 1 or the other than 1 will be null). So :-
AssessmentWithPerformanceAssessmentAndObjectiveAssessment
class AssessmentWithPerformanceAssessmentAndObjectiveAssessment {
#Embedded
Assessment assessment;
#Relation(
entity = PerformanceAssessment.class,
parentColumn = "assessment_id",
entityColumn = "assessment_reference"
)
PerformanceAssessment performanceAssessment;
#Relation(
entity = ObjectiveAssessment.class,
parentColumn = "assessment_id",
entityColumn = "assessment_reference"
)
ObjectiveAssessment objectiveAssessment;
}
A single #Dao annotated class :-
AssessmentDao
#Dao
abstract class AssessmentDao {
#Insert
abstract long insert(Assessment assessment);
#Insert
abstract long insert(PerformanceAssessment performanceAssessment);
#Insert
abstract long insert(ObjectiveAssessment objectiveAssessment);
/*
use to check if an Assessment has any children
*/
#Query("WITH cte_counts(counter) AS (" +
"SELECT count(*) > 0 FROM performance_assessment WHERE assessment_reference=:assessment_id " +
"UNION ALL SELECT count(*) FROM objective_assessment WHERE assessment_reference=:assessment_id" +
")" +
"SELECT sum(counter) > 0 FROM cte_counts")
abstract boolean hasChildAlready(long assessment_id);
#Transaction
#Query("SELECT * FROM assessment_table WHERE assessment_id=:assessment_id")
abstract AssessmentWithPerformanceAssessmentAndObjectiveAssessment getAssessmentWithPerformanceAssessmentOrObjectiveAssessmentById(long assessment_id);
#Transaction
#Query("SELECT * FROM assessment_table")
abstract List<AssessmentWithPerformanceAssessmentAndObjectiveAssessment> getAllAssessmentsWithPerformanceAssessmentOrObjectiveAssessmentById();
}
note an abstract class rather than an interface (could be an interface though)
An #Database annotated class
AssessmentDatabase
#Database(entities = {Assessment.class,PerformanceAssessment.class,ObjectiveAssessment.class},version =1)
abstract class AssessmentDatabase extends RoomDatabase {
abstract AssessmentDao getAssessmentDao();
private static volatile AssessmentDatabase instance = null;
static AssessmentDatabase getInstance(Context context) {
if (instance == null) {
instance = Room.databaseBuilder(context,AssessmentDatabase.class,"assessment.db")
.allowMainThreadQueries()
.build();
}
return instance;
}
}
note for convenience and brevity allows running on the main thread.
Finally actually using the above in an Activity:-
public class MainActivity extends AppCompatActivity {
AssessmentDatabase db;
AssessmentDao dao;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
db = AssessmentDatabase.getInstance(this);
dao = db.getAssessmentDao();
/* Various Inserts */
long loneAssessment = dao.insert(
new Assessment(
"Lone Assessment with no children",
"2021-01-15",
"2021-03-15",
0L
)
);
/* id will be 100, subsequent id's if generated will be 101,102......*/
long a1 = dao.insert(new Assessment(100,"A1","2022-01-01","2022,03-01",10));
long p1 = dao.insert(new PerformanceAssessment("P1","2022-01-31","2022-01-31",10,a1,"X"));
/* back to using generated Assessment id */
long a2 = dao.insert(new Assessment("A1","2022-01-01","2022-03-01",11));
long p2 = dao.insert(new ObjectiveAssessment("O1","2022-01-31","2022-01-31",11,a2,"Y"));
/* Build the Assessment and ObjectiveAssessment ready for insert SEE WARNING */
Assessment a10 = new Assessment("A10","2022-01-01","2022-03-01",20);
ObjectiveAssessment o10 = new ObjectiveAssessment("O10","2022-01-31","2022-01-31",a10.getCourseID(),0,"Z");
/* WARNING assessment_reference WILL NOT BE ANY GOOD (will be 0) */
long a10id = dao.insert(a10);
o10.setAssessment_reference(a10id); /*<<<<<<<<<< NOW assessment_reference should be good */
dao.insert(o10);
/* Both together */
dao.insert(
new PerformanceAssessment("P20","2022-05-07","2022-05-07",11,
/* get the Assessment ID from the insert of the Assessment */
dao.insert(
new Assessment("A20","2022-04-01","2022-06-17",21)
),
"ZZ"
)
);
/* Extract all the Assessments with their children (if any)*/
for(AssessmentWithPerformanceAssessmentAndObjectiveAssessment awpoo: dao.getAllAssessmentsWithPerformanceAssessmentOrObjectiveAssessmentById()) {
Log.d("DBINFO","Assessment is " + awpoo.assessment.getAssessmentName() + " id is " + awpoo.assessment.getAssessment_id() + " etc....");
/* need to check if the the performanceassessment is null - it will be if there isn't one */
if (awpoo.performanceAssessment != null) {
Log.d("DBINFO","\t\tPerformanceAssessment = " + awpoo.performanceAssessment.getAssessmentName() +
" id is "+ awpoo.performanceAssessment.getAssessment_id() +
" references Asessment with id " + awpoo.performanceAssessment.getAssessment_reference());
} else {
Log.d("DBINFO","\t\tNo PerformanceAssessment.");
}
/* null check see performance assessment check above */
if (awpoo.objectiveAssessment != null) {
Log.d("DBINFO","\t\tObjectiveAssessment = " + awpoo.objectiveAssessment.getAssessmentName() +
" id is "+ awpoo.objectiveAssessment.getAssessment_id() +
" references Asessment with id " + awpoo.objectiveAssessment.getAssessment_reference());
} else {
Log.d("DBINFO","\t\tNo ObjectiveAssessment.");
}
}
}
}
When run (first time, will fail if run twice due to use of 100 for the id) the log shows :-
D/DBINFO: Assessment is Lone Assessment with no children id is 1 etc....
D/DBINFO: No PerformanceAssessment.
D/DBINFO: No ObjectiveAssessment.
D/DBINFO: Assessment is A1 id is 100 etc....
D/DBINFO: PerformanceAssessment = P1 id is 1 references Asessment with id 100
D/DBINFO: No ObjectiveAssessment.
D/DBINFO: Assessment is A1 id is 101 etc....
D/DBINFO: No PerformanceAssessment.
D/DBINFO: ObjectiveAssessment = O1 id is 1 references Asessment with id 101
D/DBINFO: Assessment is A10 id is 102 etc....
D/DBINFO: No PerformanceAssessment.
D/DBINFO: ObjectiveAssessment = O10 id is 2 references Asessment with id 102
D/DBINFO: Assessment is A20 id is 103 etc....
D/DBINFO: PerformanceAssessment = P20 id is 2 references Asessment with id 103
D/DBINFO: No ObjectiveAssessment.
using App Inspection then the database looks like :-
See how PerformanceAssessment with an assessment_id of 2 (it's unqiue row identifier) has an assessment_reference value of 103. This says the the Assessment with an assessment_id of 103 is the parent (or this PerformanceAssessment relates(belongs) to the Assessment that has an assessment_id of 103).
I have a Spring Boot app with DataTables server-side processing and Oracle database. Actually, I started with implementing one of the tutorials. It worked. The tutorial uses JPA. I want to implement the same using JDBC. I made all the corresponding classes, the repository, the new model with same filds but without jpa. But when I tried to fetch the data, it allowed me to get only the first page without a chance to get to the second page. Below I will post the extracts of the original and added code. So, the original tutorial used these classes:
#Entity
#Table(name = "MYUSERS")
public class User {
#Id
#Column(name = "USER_ID")
private Long id;
#Column(name = "USER_NAME")
private String name;
#Column(name = "SALARY")
private String salary;
...getters and setters
}
And
#Entity
public class UserModel {
#Id
private Long id;
private String name;
private String salary;
private Integer totalRecords;
#Transient
private Integer rn;
...getters and setters
}
And I substituted these two classes with one like this:
public class NewUser {
private Long id;
private String name;
private String salary;
private Integer totalRecords;
private Integer rn;
...getters and setters
}
The table itself has only 3 fields: id, name and salary, the other 2 fields are created and filled later.
The repositiry the original Author has for the user looks like this:
public interface UserRepository extends JpaRepository<User, Long> {
#Query(value = "SELECT * FROM MYUSERS", nativeQuery = true)
List<User> findAllByUsernames(List<String> listOfUsernames);
}
My own repository looks like this:
#Repository
public class NewUserRepoImpl extends JdbcDaoSupport implements NewUserRepo {
private static final String SELECT_ALL_SQL = "SELECT USER_ID as id, USER_NAME as name, SALARY as salary FROM MYUSERS";
private final NamedParameterJdbcTemplate namedParameterJdbcTemplate;
private final JdbcTemplate jdbctemplate;
public NewUserRepoImpl(NamedParameterJdbcTemplate namedParameterJdbcTemplate, JdbcTemplate jdbctemplate, DataSource dataSource) {
this.namedParameterJdbcTemplate = namedParameterJdbcTemplate;
this.jdbctemplate = jdbctemplate;
setDataSource(dataSource);
}
#Override
public List<NewUser> findAll(PaginationCriteria pagination) {
try {
String paginatedQuery = AppUtil.buildPaginatedQueryForOracle(SELECT_ALL_SQL, pagination);
return jdbctemplate.query(paginatedQuery, newUserRowMapper());
} catch (DataAccessException e) {
throw new EntityNotFoundException("No Entities Found");
}
}
#Bean
public RowMapper<NewUser> newUserRowMapper() {
return (rs, i) -> {
final NewUser newUser = new NewUser();
newUser.setId(rs.getLong("ID"));
newUser.setName(rs.getString("NAME"));
newUser.setSalary(rs.getString("SALARY"));
newUser.setTotalRecords(rs.getInt("TOTAL_RECORDS"));
newUser.setTotalRecords(rs.getInt("RN"));
return newUser;
};
}
}
the buildPaginatedQueryForOracle thing transforms my Query and allows it to get the totalRecords and rn. Below I will post the output of it both for the orifinal and my queries (they are the same, I checked).
So, the main part, the controller. I left the old and new pieces in it for now for debug purposes and just returning one of the results:
#RequestMapping(value="/users/paginated/orcl", method=RequestMethod.GET)
#ResponseBody
public String listUsersPaginatedForOracle(HttpServletRequest request, HttpServletResponse response, Model model) {
DataTableRequest<User> dataTableInRQ = new DataTableRequest<User>(request);
System.out.println(new Gson().toJson(dataTableInRQ));
DataTableRequest<NewUser> dataTableInRQNew = new DataTableRequest<NewUser>(request);
System.out.println(new Gson().toJson(dataTableInRQNew));
PaginationCriteria pagination = dataTableInRQ.getPaginationRequest();
System.out.println(new Gson().toJson(pagination));
PaginationCriteria paginationNew = dataTableInRQNew.getPaginationRequest();
System.out.println(new Gson().toJson(paginationNew));
String baseQuery = "SELECT USER_ID as id, USER_NAME as name, SALARY as salary FROM MYUSERS";
String paginatedQuery = AppUtil.buildPaginatedQueryForOracle(baseQuery, pagination);
String paginatedQueryNew = AppUtil.buildPaginatedQueryForOracle(baseQuery, paginationNew);
System.out.println(paginatedQuery);
System.out.println(paginatedQueryNew);
Query query = entityManager.createNativeQuery(paginatedQuery, UserModel.class);
System.out.println("Query:");
System.out.println(query);
#SuppressWarnings("unchecked")
List<UserModel> userList = query.getResultList();
System.out.println(new Gson().toJson(userList));
#SuppressWarnings("unchecked")
List<NewUser> userListNew = newUserRepo.findAll(paginationNew);
System.out.println(new Gson().toJson(userListNew));
DataTableResults<UserModel> dataTableResult = new DataTableResults<UserModel>();
DataTableResults<NewUser> dataTableResultNew = new DataTableResults<NewUser>();
dataTableResult.setDraw(dataTableInRQ.getDraw());
dataTableResultNew.setDraw(dataTableInRQNew.getDraw());
dataTableResult.setListOfDataObjects(userList);
dataTableResultNew.setListOfDataObjects(userListNew);
if (!AppUtil.isObjectEmpty(userList)) {
dataTableResult.setRecordsTotal(userList.get(0).getTotalRecords()
.toString());
if (dataTableInRQ.getPaginationRequest().isFilterByEmpty()) {
dataTableResult.setRecordsFiltered(userList.get(0).getTotalRecords()
.toString());
} else {
dataTableResult.setRecordsFiltered(Integer.toString(userList.size()));
}
}
if (!AppUtil.isObjectEmpty(userListNew)) {
dataTableResultNew.setRecordsTotal(userListNew.get(0).getTotalRecords()
.toString());
if (dataTableInRQ.getPaginationRequest().isFilterByEmpty()) {
dataTableResultNew.setRecordsFiltered(userListNew.get(0).getTotalRecords()
.toString());
} else {
dataTableResultNew.setRecordsFiltered(Integer.toString(userListNew.size()));
}
}
System.out.println(new Gson().toJson(dataTableResult));
System.out.println(new Gson().toJson(dataTableResultNew));
return new Gson().toJson(dataTableResult);
}
So, I log out everything possible in the console. Here is the output:
{"uniqueId":"1579786571491","draw":"1","start":0,"length":5,"search":"","regex":false,"columns":[{"index":0,"data":"id","name":"ID","searchable":true,"orderable":true,"search":"","regex":false,"sortDir":"ASC"},{"index":1,"data":"name","name":"Name","searchable":true,"orderable":true,"search":"","regex":false},{"index":2,"data":"salary","name":"Salary","searchable":true,"orderable":true,"search":"","regex":false}],"order":{"index":0,"data":"id","name":"ID","searchable":true,"orderable":true,"search":"","regex":false,"sortDir":"ASC"},"isGlobalSearch":false,"maxParamsToCheck":3}
{"uniqueId":"1579786571491","draw":"1","start":0,"length":5,"search":"","regex":false,"columns":[{"index":0,"data":"id","name":"ID","searchable":true,"orderable":true,"search":"","regex":false,"sortDir":"ASC"},{"index":1,"data":"name","name":"Name","searchable":true,"orderable":true,"search":"","regex":false},{"index":2,"data":"salary","name":"Salary","searchable":true,"orderable":true,"search":"","regex":false}],"order":{"index":0,"data":"id","name":"ID","searchable":true,"orderable":true,"search":"","regex":false,"sortDir":"ASC"},"isGlobalSearch":false,"maxParamsToCheck":3}
{"pageNumber":0,"pageSize":5,"sortBy":{"mapOfSorts":{"id":"ASC"}},"filterBy":{"mapOfFilters":{},"globalSearch":false}}
{"pageNumber":0,"pageSize":5,"sortBy":{"mapOfSorts":{"id":"ASC"}},"filterBy":{"mapOfFilters":{},"globalSearch":false}}
SELECT * FROM (SELECT FILTERED_ORDERED_RESULTS.*, COUNT(1) OVER() total_records, ROWNUM AS RN FROM (SELECT BASEINFO.* FROM ( SELECT USER_ID as id, USER_NAME as name, SALARY as salary FROM MYUSERS ) BASEINFO ) FILTERED_ORDERED_RESULTS ORDER BY id ASC ) WHERE RN > (0 * 5) AND RN <= (0 + 1) * 5
SELECT * FROM (SELECT FILTERED_ORDERED_RESULTS.*, COUNT(1) OVER() total_records, ROWNUM AS RN FROM (SELECT BASEINFO.* FROM ( SELECT USER_ID as id, USER_NAME as name, SALARY as salary FROM MYUSERS ) BASEINFO ) FILTERED_ORDERED_RESULTS ORDER BY id ASC ) WHERE RN > (0 * 5) AND RN <= (0 + 1) * 5
Query:
org.hibernate.query.internal.NativeQueryImpl#3ea49a4
[{"id":3,"name":"user3","salary":"300","totalRecords":18},{"id":4,"name":"user4","salary":"400","totalRecords":18},{"id":5,"name":"user5","salary":"500","totalRecords":18},{"id":6,"name":"user6","salary":"600","totalRecords":18},{"id":7,"name":"user7","salary":"700","totalRecords":18}]
[{"id":3,"name":"user3","salary":"300","totalRecords":1},{"id":4,"name":"user4","salary":"400","totalRecords":2},{"id":5,"name":"user5","salary":"500","totalRecords":3},{"id":6,"name":"user6","salary":"600","totalRecords":4},{"id":7,"name":"user7","salary":"700","totalRecords":5}]
{"draw":"1","recordsFiltered":"18","recordsTotal":"18","data":[{"id":3,"name":"user3","salary":"300","totalRecords":18},{"id":4,"name":"user4","salary":"400","totalRecords":18},{"id":5,"name":"user5","salary":"500","totalRecords":18},{"id":6,"name":"user6","salary":"600","totalRecords":18},{"id":7,"name":"user7","salary":"700","totalRecords":18}]}
{"draw":"1","recordsFiltered":"1","recordsTotal":"1","data":[{"id":3,"name":"user3","salary":"300","totalRecords":1},{"id":4,"name":"user4","salary":"400","totalRecords":2},{"id":5,"name":"user5","salary":"500","totalRecords":3},{"id":6,"name":"user6","salary":"600","totalRecords":4},{"id":7,"name":"user7","salary":"700","totalRecords":5}]}
It helped me realize that:
DataTableRequest incoming from the back is the same for both jpa
and jdbc
PaginationCriteria are also the same
paginatedQuery
having been made with the method specified above are the same.
Differences are already seen in the Lists: where the Jpa list
retrieved with native Query has totalRecords as 18 for every row,
the JDBC repo with the same query returns 1,2,3... for every
subsequent row.
It made me think that I should look at the Query made for JPA. But, as you see in the log, System.out.println wasn't able to decipher it for some reason.
Any advice on how to decipher it and more importantly how to get the right total result for each row would be greatly appreciated!!!
I'm trying to unit-test my DAO using android-room. I have written an insert test that works properly. Unfortunately, the delete method doesn't seem to be working.
I've tried a few different setups for the test. None have worked.
Here is the DAO:
#Dao
public interface MonthlyDao {
#Insert(onConflict = OnConflictStrategy.REPLACE)
void saveAll(List<Monthly> goals);
#Insert(onConflict = OnConflictStrategy.REPLACE)
void save(Monthly goal);
#Update
void update(Monthly goal);
#Delete
void delete(Monthly goal);
#Query("SELECT * FROM Monthly")
LiveData<List<Monthly>> findAll();
#Query("SELECT * FROM monthly")
List<Monthly> findAllList();
}
Here is the Monthly entity:
#Entity
public class Monthly {
#PrimaryKey(autoGenerate = true)
private int monthlyId;
#TypeConverters(CalendarTypeConverter.class)
#ColumnInfo(name = "date")
private Calendar date = Calendar.getInstance();
#ColumnInfo(name = "title")
private String title;
#ColumnInfo(name = "description")
private String description;
#ColumnInfo(name = "completed")
private boolean completed;
...
public int getMonthlyId() {
return monthlyId;
}
public void setMonthlyId(int monthlyId) {
this.monthlyId = monthlyId;
}
And here is the test I am running:
#RunWith(AndroidJUnit4.class)
public class MonthlyTest {
private MonthlyDao monthlyDao;
private MonthlyGoalsDatabase db;
#Before
public void createDb() {
Context context = ApplicationProvider.getApplicationContext();
db = Room.inMemoryDatabaseBuilder(context, MonthlyGoalsDatabase.class).build();
monthlyDao = db.getMonthlyDao();
}
#After
public void closeDb() throws IOException {
db.close();
}
#Test
public void deleteGoal() throws Exception {
String title = "test delete title";
Calendar date = Calendar.getInstance();
date.set(Calendar.HOUR_OF_DAY, 0);
String desc = "test delete desc";
Monthly goal = new Monthly(title, date, desc);
monthlyDao.save(goal);
List<Monthly> goals = monthlyDao.findAllList();
Assert.assertThat(goals.get(0).getTitle(), equalTo(goal.getTitle()));
monthlyDao.delete(goal);
List<Monthly> updatedGoals = monthlyDao.findAllList();
Assert.assertTrue(updatedGoals.isEmpty());
}
I except the updatedGoals list to be empty, but it isn't. There is still the goal that I inserted during the test.
The method annotated with #Delete uses the primary key on the entity to know which row to delete from the database (because there could be multiple rows with the same data but different keys).
However, you're using the initial goal object that you created, which has no primary key, and thus cannot be used to indicate which row to remove.
Try doing this:
monthlyDao.save(goal);
List<Monthly> goals = monthlyDao.findAllList();
Assert.assertThat(goals.get(0).getTitle(), equalTo(goal.getTitle()));
monthlyDao.delete(goals.get(0)); // <-- Delete the goal returned from the find, which will have an ID
List<Monthly> updatedGoals = monthlyDao.findAllList();
Assert.assertTrue(updatedGoals.isEmpty());
That could easily be cleaned up a bit, but the above example only changes one line, to make it clear where the issue is.
See here for the relevant documentation.
I am trying to set the Parent List in a ParameterizedRowMapper how is this written or approached. I have two Objects one for parent and one for children however children contains a ListThe parents for each child are stored in a separate table in the database and the mapping is 1 - many.
The select for the records for the parents will be done in a separate ResultSet. Will the mapping have to be done separately (separate ParameterizedRowMapper), if so how will i have to write the ParameterizedRowMapper this is the major concern how ParameterizedRowMapper is written to accommodate a list items.
ParameterizedRowMapper
public static class ChildrenMapper implements ParameterizedRowMapper<Children>{
public Children mapRow(ResultSet rs, int rowNum) throws SQLException {
Children child = new Children();
child.setFirstName(rs.getString("firstName"));
child.setLastName(rs.getString("lastName"));
//a child can have many Parents or gaurdians
child.setParent(List<Parent>);
return child;
}
}
Based on my research i have found that i need to use ResultSetExtractor, however i have a questions on the use of that. Do i integrate it into the class at the point of setting the Parent? Can someone guide me on how it can be done the correct way
Children.java
Public class Children(){
int cid;
String firstName;
String lastName;
List<Parent>parents;
..
//getters/setters
}
Parent.java
Public class Parent(){
int pid;
String firstName;
String lastName;
..
//setters/getters
}
I will show how to do this for a canonical 1-to-many example, you can adapt it to your vo class / table.
Order class
public class Order {
private Long orderId;
private String user;
private List<LineItem> items;
// Getter / setter omitted
}
Item class
public class LineItem {
private Long lineItemId;
private String product;
private int quantity;
// Getter / setter omitted
}
Use two rowmappers one for each class and then use a result set extractor to convert multiple rows into one order + line items
OrderRepository
public final static RowMapper<Order> orderMapper = ParameterizedBeanPropertyRowMapper.newInstance(Order.class);
public final static RowMapper<LineItem> lineItemMapper = ParameterizedBeanPropertyRowMapper.newInstance(LineItem.class);
public Order findOrderWithItems(Long orderId) {
return jdbcTemplate.query("select * from orders, line_item "
+ " where orders.order_id = line_item.order_id and orders.order_id = ?",
new ResultSetExtractor<Order>() {
public Order extractData(ResultSet rs) throws SQLException, DataAccessException {
Order order = null;
int row = 0;
while (rs.next()) {
if (order == null) {
order = orderMapper.mapRow(rs, row);
}
order.addItem(lineItemMapper.mapRow(rs, row));
row++;
}
return order;
}
}, orderId);
}
public List<Order> findAllOrderWithItmes() {
return jdbcTemplate.query("select * from orders, line_item "
+ " where orders.order_id = line_item.order_id order by orders.order_id",
new ResultSetExtractor<List<Order>>() {
public List<Order> extractData(ResultSet rs) throws SQLException, DataAccessException {
List<Order> orders = new ArrayList<Order>();
Long orderId = null;
Order currentOrder = null;
int orderIdx = 0;
int itemIdx = 0;
while (rs.next()) {
// first row or when order changes
if (currentOrder == null || !orderId.equals(rs.getLong("order_id"))) {
orderId = rs.getLong("order_id");
currentOrder = orderMapper.mapRow(rs, orderIdx++);
itemIdx = 0;
orders.add(currentOrder);
}
currentOrder.addItem(lineItemMapper.mapRow(rs, itemIdx++));
}
return orders;
}
});
}