I'm Android: 2016

This post deals with sql database operation simplification all at one place.

For database operation we mainly need a method that returns ContentValues (For insert and update) and Constraints( for update and delete and find) and a method called contentToModel that returns data in list containing each row data as a model ( List<TableRow> )

TableRow.java class was an abstract class containing method to return ContentValues, say modelToContentValues()

/**
* Created by Naresh on 22/03/16.
*/
public abstract class TableRow{
@NonNull
public abstract ContentValues modelToContentValues();
}

DatabaseOperationManager.java is the class that contains all basic database operations

public abstract class DatabaseOperation<T extends TableRow> {
SQLiteDatabase database;
String table_name;

public DatabaseOperation(SQLiteDatabase database, String table_name) {
this.database = database;
this.table_name = table_name;
}

public long insert(T row) {
return database.insert(table_name, null, row.modelToContentValues());
}

public List<T> all() {
return all(null);
}

public List<T> all(String sort_by) {
Cursor cursor = database.query(table_name, new String[]{"*"}, null, null, null, null, sort_by);
return cursorToModel(cursor);
}

public abstract int update(T row);

public int update(T row, String constraint) {
ContentValues values = row.modelToContentValues();
return database.update(table_name, values, constraint, null);
}

public List<T> find(String[] constraint_columns, Object[] constraint_values) throws Exception {
String where_clause;
if (constraint_columns == null && constraint_values == null)
return all();
else if (constraint_columns == null) {
throw new Exception("invalid column names");
} else if (constraint_columns.length != constraint_values.length)
throw new Exception("constraint columns and constrain values size are not matched");
else {
if (constraint_columns[0] == null)
throw new Exception("Invalid column null at position 0");
where_clause = constraint_columns[0] + (constraint_values[0] == null ? "" : (constraint_values[0] instanceof Number ? " = " : " like \"") + constraint_values[0] + (constraint_values[0] instanceof Number ? "" : "\""));
for (int i = 1; i < constraint_columns.length; i++) {
if (constraint_columns[i] == null)
throw new Exception("Invalid column null at position " + i);
where_clause = where_clause + " and " + constraint_columns[i] + (constraint_values[i] == null ? "" : " like \"") + constraint_values[i] + (constraint_values[i] instanceof Number ? "" : "\"");
}
}
String[] columns = new String[]{"*"};
Cursor cursor = database.query(table_name, columns, where_clause, null, null, null, null);
return cursorToModel(cursor);
}

public int delete(String where_clause) {
return database.delete(table_name, where_clause, null);
}

public int clear() {
return delete("1");
}

@NonNull
public abstract List<T> cursorToModel(Cursor cursor);
}

the thing you need t do are much simpler just extend these two classes like this

/**

* Created by Naresh on 23/04/16.

public class PatientStatus extends TableRow {

Integer id;

String status_code;

String status_name;

String status_description;

String next_step;

String created_at;

String updated_at;

public void setId(Integer id) {

this.id = id;

}

public void setStatus_code(String status_code) {

this.status_code = status_code;

}

public void setStatus_name(String status_name) {

this.status_name = status_name;

}

public void setStatus_description(String status_description) {

this.status_description = status_description;

}

public void setNext_step(String next_step) {

this.next_step = next_step;

}

public void setCreated_at(String created_at) {

this.created_at = created_at;

}

public void setUpdated_at(String updated_at) {

this.updated_at = updated_at;

}

@NonNull

@Override

public ContentValues modelToContentValues() {

ContentValues values = new ContentValues();

if (id != null)

values.put("ID", id);

if (status_code != null)

values.put("STATUS_CODE", status_code);

if (status_name != null)

values.put("STATUS_NAME", status_name);

if (status_description != null)

values.put("STATUS_DESCRIPTION", status_description);

if (next_step != null)

values.put("NEXT_STEP", next_step);

if (created_at != null)

values.put("CREATED_ON", created_at);

if (updated_at != null)

values.put("UPDATED_ON", updated_at);

return values;

}

and

/**

* Created by Naresh on 23/04/16.

public class StatusOperation extends DatabaseOperation<Status> {

public StatusMasterOperation(SQLiteDatabase database) {

super(database, "STATUS_TABLE");

}

@Override

public int update(Status row) {

return update(row, "ID" + " = \"" + row.getId() + "\"");

}

@NonNull

@Override

public List<Status> cursorToModel(Cursor cursor) {

List<Status> list = new ArrayList<>();

while (cursor.moveToNext()) {

Status status = new Status();

int index = cursor.getColumnIndex("ID");

if (index != -1)