![]() Now in the post, inside the Model folder, they added an ADO.NET Entity Data Model that connects to the Students table in the database and named it StudentModel while changing connectionstring name to StudentEntities.īut, I have a local SQLite database, how do I change that and what other things I need to change to make this app work? This.DataContext = new StudentViewModel() Propert圜hanged(this, new Propert圜hangedEventArgs(propertyName)) Protected void OnPropert圜hanged(string propertyName) ![]() Public event Propert圜hangedEventHandler Propert圜hanged Public class ViewModelBase : INotifyPropert圜hanged ViewModelBase.cs using System.ComponentModel _repository.GetAll().ForEach(data => (new StudentRecord() _studentEntity.stdContact = StudentRecord.Contact _studentEntity.stdAddress = StudentRecord.Address _studentEntity.stdAge = StudentRecord.Age _studentEntity.stdName = StudentRecord.Name MessageBox.Show("Error occured while saving. MessageBox.Show("Record successfully deleted.") If (MessageBox.Show("Confirm delete of this record?", "Student", MessageBoxButton.YesNo) _deleteCommand = new Rela圜ommand(param => DeleteStudent((int)param), null) _editCommand = new Rela圜ommand(param => EditData((int)param), null) _saveCommand = new Rela圜ommand(param => SaveData(), null) _resetCommand = new Rela圜ommand(param => ResetData(), null) Public event EventHandler CanExecuteChangedĪdd Return _canExecute = null ? true : _canExecute(parameter) Throw new ArgumentNullException("execute") Public Rela圜ommand(Action execute, Predicate canExecute) Public ObservableCollection StudentRecords Private ObservableCollection _studentRecords Public class StudentRecord : ViewModelBase Var query = "SELECT * FROM tblStud WHERE stdId = args = new student.stdId} Public void RemoveStudent(Student student)Ĭonst string query = "Delete from tblStud WHERE stdId = args = new student.stdId} Public void UpdateStudent(Student student)Ĭonst string query = "UPDATE tblStud SET stdName = stdAge = stdAddress = stdContact = WHERE stdId = args = new student.stdContact} Public DataTable Execute(string query, Dictionary args)Ĭmd.Parameters.AddWithValue(entry.Key, entry.Value) Ĭonst string query = "INSERT INTO tblStud(stdName, stdAge, stdAddress, stdContact) args = new student.stdContact} Using (var cmd = new SQLiteCommand(query, con))Ĭmd.Parameters.AddWithValue(pair.Key, pair.Value) Using (var con = new Source=/.Students.db ")) Public void ExecuteWrite(string query, Dictionary args) Also, for someone who is new to MVVM pattern it seems pretty intimidating to say the least.Īnyways, coming to the point, I've found this post online and tried my best to make it work for SQLite databases but struggling at the moment. These expressions are used in various data manipulations.I'm totally new to MVVM and I've been going through a lot of online posts regarding how do I implement CRUD operations and properly bind SQLite database data to WPF controls like Datagrid, Combobox, Textbox, Button etc. Sqlite> SELECT COUNT(*) AS "RECORDS" FROM COMPANY ĭate Expressions returns the current system date and time values. There are several built-in functions such as avg(), sum(), count(), etc., to perform what is known as aggregate data calculations against a table or a specific table column. Following is a simple example showing the usage of SQLite Numeric Expressions. ![]() Here, numerical_expression is used for mathematical expression or any formula. SELECT numerical_expression as OPERATION_NAME These expressions are used to perform any mathematical operation in any query. Sqlite> SELECT * FROM COMPANY WHERE SALARY = 10000 Following is the syntax −Ĭonsider COMPANY table with the following records −įollowing is a simple examples showing the usage of SQLite Boolean Expressions − SQLite Boolean Expressions fetch the data on the basis of matching single value. SyntaxĬonsider the basic syntax of the SELECT statement as follows −įollowing are the different types of SQLite expressions. ![]() You can also use to query the database for a specific set of data. SQL expressions are like formulas and they are written in query language. An expression is a combination of one or more values, operators, and SQL functions that evaluate to a value.
0 Comments
Leave a Reply. |