当我将新员工添加到部门到我的数据库时，它总是返回只有1个条目的游标，而没有添加其他游标（此处我正在对ID为2的部门进行试用）
活动代码
private EmployeesManagementDbHelper helper;
private ListView employees;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.department);
helper = new EmployeesManagementDbHelper(this);
helper.addEmployee("Name","03-03-1990",2,"lk",null,null,null);
helper.addEmployee("Name","03-03-1990",2,"lk",null,null,null);
Intent intent = getIntent();
final long departmentId = intent.getExtras().getLong("departmentId");
//setting list of employees in this department
employees = findViewById(R.id.employees_list);
Cursor cursorEmp = helper.getEmployessOfDepartment(departmentId);
Log.i("depActivity",String.valueOf(cursorEmp.getCount()));
//it always gets me 1 even if there are more
EmployeeAdapter adapterEmp = new EmployeeAdapter(this, cursorEmp);
employees.setAdapter(adapterEmp);
}
插入新员工的方法
addEmployee
public boolean addEmployee(String employee_name, String
employee_birthdate ,long department_id,String employee_job,String
employee_email,String employee_phone,String employee_photo){
//adds an employee entry to employee table
SQLiteDatabase db = this.getWritableDatabase();
ContentValues cv = new ContentValues();
cv.put(EmployeeEntry.COLUMN_EMPLOYEE_NAME,employee_name);
cv.put(EmployeeEntry.COLUMN_EMPLOYEE_BIRTHDATE,employee_birthdate);
cv.put(EmployeeEntry.COLUMN_EMPLOYEE_DEPARTMENT_ID,department_id);
cv.put(EmployeeEntry.COLUMN_EMPLOYEE_JOB,employee_job);
if(employee_email!=null && !employee_email.isEmpty()&&!employee_email.trim().isEmpty()) // to be edited //checks if field is provided if not it is not added in the query
cv.put(EmployeeEntry.COLUMN_EMPLOYEE_EMAIL,employee_email);
if(employee_phone!=null && !employee_phone.isEmpty()&&!employee_phone.trim().isEmpty()) // to be edited
cv.put(EmployeeEntry.COLUMN_EMPLOYEE_PHONE,employee_phone);
if(employee_photo!=null && !employee_photo.isEmpty()&&!employee_photo.trim().isEmpty())
cv.put(EmployeeEntry.COLUMN_EMPLOYEE_PHOTO,employee_photo);
long flag = db.insert(EmployeeContract.TABLE_NAME,null,cv);
if(flag==-1) return false;
return true;
}
让所有员工在特定部门工作的方法
getEmployeesOfDepartment
public Cursor getEmployessOfDepartment(long department_id)
{
//gets all employees of a given department
SQLiteDatabase db = this.getReadableDatabase();
String [] columns = {
EmployeeEntry._ID,
EmployeeEntry.COLUMN_EMPLOYEE_EMAIL,
EmployeeEntry.COLUMN_EMPLOYEE_BIRTHDATE,
EmployeeEntry.COLUMN_EMPLOYEE_PHONE,
EmployeeEntry.COLUMN_EMPLOYEE_NAME,
EmployeeEntry.COLUMN_EMPLOYEE_JOB,
EmployeeEntry.COLUMN_EMPLOYEE_DEPARTMENT_ID,
EmployeeEntry.COLUMN_EMPLOYEE_PHOTO
};
String selection = DepartmentEntry._ID + " =?"; //where statement
String selectionArgs[] = { String.valueOf(department_id) };
String orderBy = EmployeeEntry.COLUMN_EMPLOYEE_NAME + " ASC";
//cursor is a table containing the rows returned form the query
Cursor cursor = db.query(EmployeeContract.TABLE_NAME,columns,selection,selectionArgs,null,null,orderBy); //don't forget to close the cursor after usage
Log.i("helper",String.valueOf(cursor.getCount()));
return cursor; }
public class EmployeesManagementDbHelper extends SQLiteOpenHelper {
private static final String DATABASE_NAME = "employees_management.db";
private static final int DATABASE_VERSION = 1;
public EmployeesManagementDbHelper(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
//This is called when the database is created for the first time
@Override
public void onCreate(SQLiteDatabase db) {
// Create a String that contains the SQL statement to create the employee table
String SQL_CREATE_EMPLOYEE_TABLE = "CREATE TABLE " + EmployeeContract.TABLE_NAME + "("
+ EmployeeEntry._ID + " INTEGER PRIMARY KEY AUTOINCREMENT,"
+ EmployeeEntry.COLUMN_EMPLOYEE_NAME + " VARCHAR(70) NOT NULL, "
+ EmployeeEntry.COLUMN_EMPLOYEE_BIRTHDATE + " DATE NOT NULL,"
+EmployeeEntry.COLUMN_EMPLOYEE_DEPARTMENT_ID + " INTEGER NOT NULL,"
+ EmployeeEntry.COLUMN_EMPLOYEE_JOB + " VARCHAR(50) NOT NULL,"
+ EmployeeEntry.COLUMN_EMPLOYEE_PHONE + " VARCHAR(20),"
+ EmployeeEntry.COLUMN_EMPLOYEE_EMAIL + " VARCHAR(255),"
+ EmployeeEntry.COLUMN_EMPLOYEE_PHOTO + " VARCHAR(255), "
+ "FOREIGN KEY(" + EmployeeEntry.COLUMN_EMPLOYEE_DEPARTMENT_ID + ") REFERENCES " + DepartmentContract.TABLE_NAME + "(" + DepartmentEntry._ID + ")"
+ ");";
// Create a String that contains the SQL statement to create the department table
String SQL_CREATE_DEPARTMENT_TABLE = "CREATE TABLE " + DepartmentContract.TABLE_NAME+"("
+DepartmentEntry._ID + " INTEGER PRIMARY KEY AUTOINCREMENT, "
+DepartmentEntry.COLUMN_DEPARTMENT_NAME + " VARCHAR(255) NOT NULL UNIQUE, "
+DepartmentEntry.COLUMN_DEPARTMENT_DESCRIPTION + " VARCHAR(300) "
+");";
// Create a String that contains the SQL statement to create the task table
String SQL_CREATE_TASK_TABLE = "CREATE TABLE " + TaskContract.TABLE_NAME + "("
+TaskEntry._ID + " INTEGER PRIMARY KEY AUTOINCREMENT, "
+TaskEntry.COLUMN_TASK_NAME + " VARCHAR(70) NOT NULL, "
+TaskEntry.COLUMN_TASK_DESCRIPTION + " VARCHAR(300), "
+TaskEntry.COLUMN_TASK_DEADLINE + " DATETIME ,"
+TaskEntry.COLUMN_TASK_EVALUATION + "INTEGER NOT NULL"
+");"
;
// Create a String that contains the SQL statement to create the employee_task table
String SQL_CREATE_EMPLOYEE_TASK_TABLE = "CREATE TABLE " + "employee_task " + "( "
+ EmployeeContract.TABLE_NAME+EmployeeEntry._ID + " INTEGER NOT NULL, "
+ TaskContract.TABLE_NAME+TaskEntry._ID+ " INTEGER NOT NULL, "
+ "FOREIGN KEY (" + EmployeeContract.TABLE_NAME+EmployeeEntry._ID + ") REFERENCES " + EmployeeContract.TABLE_NAME + "(" + EmployeeEntry._ID + "), "
+ "FOREIGN KEY (" + TaskContract.TABLE_NAME+TaskEntry._ID + ") REFERENCES " + TaskContract.TABLE_NAME +"(" + TaskEntry._ID + ") "
+");"
;
//executes SQL create statements
db.execSQL(SQL_CREATE_DEPARTMENT_TABLE);
db.execSQL(SQL_CREATE_EMPLOYEE_TABLE);
db.execSQL(SQL_CREATE_TASK_TABLE);
db.execSQL(SQL_CREATE_EMPLOYEE_TASK_TABLE);
}
//This is called when the database needs to be upgraded.
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
// The database is still at version 1, so there's nothing to do be done here.
// DATABASE_VERSION ++;
}
public Cursor getAllTasksCursor(){
//gets all tasks
SQLiteDatabase db = this.getReadableDatabase(); //get readable instance of the db
//specify the columns to be read
String [] columns = {
TaskEntry.COLUMN_TASK_NAME,
TaskEntry.COLUMN_TASK_DESCRIPTION,
TaskEntry.COLUMN_TASK_EVALUATION,
TaskEntry.COLUMN_TASK_DEADLINE
};
//cursor is a table containing the rows returned form the query
Cursor cursor = db.query(TaskContract.TABLE_NAME,columns,null,null,null,null,null);
return cursor; //don't forget to close the cursor after usage
}
public Cursor getSpecifiTaskCursor(long task_id){
//gets specific task by its id
SQLiteDatabase db = this.getReadableDatabase(); //get readable instance of the db
//specify the columns to be read
String [] columns = {
TaskEntry.COLUMN_TASK_NAME,
TaskEntry.COLUMN_TASK_DESCRIPTION,
TaskEntry.COLUMN_TASK_EVALUATION,
TaskEntry.COLUMN_TASK_DEADLINE
};
//where statement to filter quere
String selection = TaskEntry._ID + " =?"; //where TaskEntry._ID=task_id
String selectionArgs[] = { String.valueOf(task_id) };
//cursor is a table containing the rows returned form the query
Cursor cursor = db.query(TaskContract.TABLE_NAME,columns,null,null,null,null,null);
return cursor; //don't forget to close the cursor after usage
}
public Cursor getAllDepartments()
{
//gets all departments
SQLiteDatabase db = this.getReadableDatabase(); //get readable instance of the db
//specify the columns to be read
String [] columns = {
DepartmentEntry._ID,
DepartmentEntry.COLUMN_DEPARTMENT_NAME,
DepartmentEntry.COLUMN_DEPARTMENT_DESCRIPTION
};
String orderBy = DepartmentEntry.COLUMN_DEPARTMENT_NAME + " ASC "; //order by statement
//cursor is a table containing the rows returned form the query
Cursor cursor = db.query(DepartmentContract.TABLE_NAME,columns,null,null,null,null,orderBy);
return cursor; //don't forget to close the cursor after usage
}
public Cursor getDepartment(Long departmentId){
SQLiteDatabase db = this.getReadableDatabase(); //get readable instance of the db
//specify the columns to be read
String [] columns = {
DepartmentEntry._ID,
DepartmentEntry.COLUMN_DEPARTMENT_NAME,
DepartmentEntry.COLUMN_DEPARTMENT_DESCRIPTION
};
String selection = DepartmentEntry._ID + " =?"; //where statement
String selectionArgs[] = { String.valueOf(departmentId) };
return db.query(DepartmentContract.TABLE_NAME,columns,selection,selectionArgs,null,null,null);
}
public Cursor getEmployessOfDepartment(long department_id)
{
SQLiteDatabase db = this.getReadableDatabase();
String [] columns = {
EmployeeEntry._ID,
EmployeeEntry.COLUMN_EMPLOYEE_EMAIL,
EmployeeEntry.COLUMN_EMPLOYEE_BIRTHDATE,
EmployeeEntry.COLUMN_EMPLOYEE_PHONE,
EmployeeEntry.COLUMN_EMPLOYEE_NAME,
EmployeeEntry.COLUMN_EMPLOYEE_JOB,
EmployeeEntry.COLUMN_EMPLOYEE_DEPARTMENT_ID,
EmployeeEntry.COLUMN_EMPLOYEE_PHOTO
};
String selection = DepartmentEntry._ID + " =?"; //where statement
String selectionArgs[] = { String.valueOf(department_id) };
String orderBy = EmployeeEntry.COLUMN_EMPLOYEE_NAME + " ASC";
//cursor is a table containing the rows returned form the query
Cursor cursor = db.query(EmployeeContract.TABLE_NAME,columns,selection,selectionArgs,null,null,orderBy); //don't forget to close the cursor after usage
return cursor; }
public boolean addDepartment(String department_name , String department_description)
{
SQLiteDatabase db = this.getWritableDatabase(); //gets writeable instance of database
ContentValues cv = new ContentValues(); //used for inserting an entry
cv.put(TaskEntry.COLUMN_TASK_NAME,department_name);
if(department_description!=null && !department_description.isEmpty()&&!department_description.trim().isEmpty()) // to be edited
cv.put(TaskEntry.COLUMN_TASK_DESCRIPTION,department_description);
long flag = db.insert(DepartmentContract.TABLE_NAME,null,cv); //reutrns a flag to indicate succes of insertion
if(flag==-1) return false; //-1 if insert fails
return true;
}
public boolean addEmployee(String employee_name, String employee_birthdate ,long department_id,String employee_job,String employee_email,String employee_phone,String employee_photo){
//adds an employee entry to employee table
SQLiteDatabase db = this.getWritableDatabase(); //gets writeable instance of database
ContentValues cv = new ContentValues(); //used for inserting an entry
// no need to check for null as it is required to be provided
cv.put(EmployeeEntry.COLUMN_EMPLOYEE_NAME,employee_name);
cv.put(EmployeeEntry.COLUMN_EMPLOYEE_BIRTHDATE,employee_birthdate);
cv.put(EmployeeEntry.COLUMN_EMPLOYEE_DEPARTMENT_ID,department_id);
cv.put(EmployeeEntry.COLUMN_EMPLOYEE_JOB,employee_job);
if(employee_email!=null && !employee_email.isEmpty()&&!employee_email.trim().isEmpty()) // to be edited //checks if field is provided if not it is not added in the query
cv.put(EmployeeEntry.COLUMN_EMPLOYEE_EMAIL,employee_email);
if(employee_phone!=null && !employee_phone.isEmpty()&&!employee_phone.trim().isEmpty()) // to be edited
cv.put(EmployeeEntry.COLUMN_EMPLOYEE_PHONE,employee_phone);
if(employee_photo!=null && !employee_photo.isEmpty()&&!employee_photo.trim().isEmpty())
cv.put(EmployeeEntry.COLUMN_EMPLOYEE_PHOTO,employee_photo);
long flag = db.insert(EmployeeContract.TABLE_NAME,null,cv); //reutrns a flag to indicate succes of insertion
if(flag==-1) return false; //-1 if insert fails
return true;
}
public boolean addTask(String task_name, int task_evaluation , String task_description, String task_deadline, ArrayList<Long> emplyee_ids)
{
//adds task to db
SQLiteDatabase db = this.getWritableDatabase(); //gets writeable instance of database
ContentValues cv = new ContentValues(); //used for inserting an entry
cv.put(TaskEntry.COLUMN_TASK_NAME,task_name);
cv.put(TaskEntry.COLUMN_TASK_EVALUATION, task_evaluation);
if(task_description!=null && !task_description.isEmpty()&&!task_description.trim().isEmpty())
cv.put(TaskEntry.COLUMN_TASK_DESCRIPTION,task_description);
if(task_deadline!=null && !task_deadline.isEmpty()&&!task_deadline.trim().isEmpty())
cv.put(TaskEntry.COLUMN_TASK_DEADLINE,task_deadline);
long task_id = db.insert(TaskContract.TABLE_NAME,null,cv); //reutrns a flag to indicate succes of insertion
if(task_id==-1) return false; //-1 if insert fails
cv = new ContentValues();
if (emplyee_ids!=null)
{
for(long emp_id:emplyee_ids){
cv.put(EmployeeEntry._ID,emp_id);
cv.put(TaskEntry._ID,task_id);
long flag = db.insert("employee_task",null,cv); //reutrns a flag to indicate succes of insertion
if(flag==-1) return false;
}
}
else return false;
return true;
}
public boolean deleteEmployee(long employee_id){
SQLiteDatabase db = this.getWritableDatabase(); //gets writeable instance of database
db.delete("employee_task",EmployeeContract.TABLE_NAME+EmployeeEntry._ID+ "="+employee_id,null);
int flag = db.delete(EmployeeContract.TABLE_NAME,EmployeeEntry._ID + "=" + employee_id,null) ;
return flag>0;
}
public boolean deleteTask(long task_id){
SQLiteDatabase db = this.getWritableDatabase(); //gets writeable instance of database
db.delete("employee_task",TaskContract.TABLE_NAME+TaskEntry._ID+ "="+task_id,null);
int flag = db.delete(TaskContract.TABLE_NAME,TaskEntry._ID + "=" + task_id,null);
return flag>0;
}
public boolean deleteDepartment(long department_id){
SQLiteDatabase db = this.getWritableDatabase(); //gets writeable instance of database
Cursor c = getEmployessOfDepartment(department_id);
while(c.moveToNext()) {
db.delete("employee_task",EmployeeContract.TABLE_NAME+EmployeeEntry._ID + " = "+c.getString(0),null);
}
c.close();
db.delete(EmployeeContract.TABLE_NAME,DepartmentEntry._ID + "=" + department_id,null);
int flag = db.delete(DepartmentContract.TABLE_NAME,DepartmentEntry._ID + "=" + department_id,null) ;
return flag>0;
}
}
答案 0 :(得分：1)
您是否对getEmployessOfDepartment方法中的这一行感兴趣：
String selection = DepartmentEntry._ID + " =?"; //where statement
据我所知，它只会给您具有给定_ID的行-因此它将始终为1行。
也许您应该在这里使用EmployeeEntry.COLUMN_EMPLOYEE_DEPARTMENT_ID，因为我了解您的目标是正确的。