/// <summary>
/// Creates the query for updating data in the datasource.
/// </summary>
///
/// <returns>
/// Generated Update query.
/// </returns>
private string CreateUpdateString()
{
string tableName = GetType().Name;
StringBuilder stringBuilder = new StringBuilder($"UPDATE [{tableName}]{Environment.NewLine}SET ");
foreach (PropertyInfo property in SchemaFieldProperties.Where(pi => !pi.GetCustomAttribute <SchemaField>().IsPrimaryKey))
{
stringBuilder.Append($"[{property.Name}] = @{property.Name}");
if (!property.Name.Equals(SchemaFieldProperties.Last().Name))
{
stringBuilder.Append($", ");
}
}
stringBuilder.Append($"{Environment.NewLine}WHERE {PrimaryKeyPropertyInfo.Name} = {PrimaryKeyPropertyInfo.GetValue(this)}");
return(stringBuilder.ToString());
}
/// <summary>
/// Deletes the <seealso cref="DBObject"/> from the datasource.
/// </summary>
///
/// <example>
/// The following example shows how to <see cref="Delete"/> a <seealso cref="Customer"/> with a username of "billy123" from the datasource.
/// <code>
/// DBObject.GetAllRecords<"Customer">().Where(cust => cust.Username == "billy123").FirstOrDefault().Delete();
/// </code>
/// </example>
///
/// <example>
/// The following example shows an alternative way to <see cref="Delete"/> a <seealso cref="Customer"/> with a username of "billy123" from the datasource.
/// <code>
/// List<Customer> customers = DBObject.GetAllRecords<Customer>();
/// customers.Where(cust => cust.Username == "billy123").FirstOrDefault().Delete();
/// </code>
/// </example>
///
/// <returns>
/// Whether the delete was successful or not.
/// </returns>
/// <exception cref="OleDbException">
/// Throws an exception when a foreign key linkage is being violated.
/// </exception>
public bool Delete()
{
using (OleDbConnection dbConnection = new OleDbConnection(CONNECTION_STRING))
{
string table = GetType().Name;
string query = $"DELETE FROM {table} WHERE {PrimaryKeyPropertyInfo.Name} = {PrimaryKeyPropertyInfo.GetValue(this)}";
int rowsAffected;
using (OleDbCommand command = new OleDbCommand(query, dbConnection))
{
dbConnection.Open();
try
{
rowsAffected = command.ExecuteNonQuery();
}
catch (OleDbException ex)
{
Console.Error.WriteLine(ex.Message);
throw;
}
}
return(rowsAffected != 0);
}
}
