Resultset Object

Using the Resultset object and its associated methods you can read records from a data table in a DataWeb web. For an explanation of the method arguments see the Data Access Method Arguments discussion.

Constructor

[new] Resultset (tablename, columns, filter[, sort])

A Resultset object instance is constructed and returned or an exception is thrown. tablename specifies the table on which the query operates, columns specifies the columns to return, filter is used to select a subset of the entries of the data table to be returned, and, optionally, sort names a column with a +/- preceding the name to determine the ascending or descending order of the returned data.

Instance Properties

A Resultset object instance has properties corresponding to the columns in the table specified at resultset construction. The values of these properties depend on the position of the resultset cursor. If the cursor does not point at a valid record, attempting to access a field will throw an exception. If the cursor points to a valid record, the property values correspond to the current record's database values.

Instance Methods

afterLast	Positions the record cursor after the last record.
beforeFirst	Positions the record cursor before the first record.
getCount	Returns the number of records actually present in the resultset.
getCSV	Returns the Resultset formatted as a CSV file.
getFieldList	Returns an Array object instance containing the names of all the columns returned by the query.
getTablename	Returns the name of the table from which this resultset was selected.
getXML	Returns the Resultset formatted as an XML file.
hasPosition	Returns a boolean value indicating whether the cursor points to a valid record.
isComplete	Returns TRUE or FALSE depending on whether the resultset represents all the database records that actually match the specified filter.
next	Advances the record cursor by one record.
previous	Moves the cursor back one record.
sendCSV	Sends the Resultset directly to the browser formatted as a CSV file.
sendXML	Send the Resultset directly to the browser formatted as an XML file.

Example

The following example constructs and returns a ResultSet object containing data from three fields (LastName, FirstName, and Email) of the AddressBook data table. Only those records where the LastName field has the value "Smith" are returned. The records are returned sorted alphabetically on the FirstName field.

  var rs = new ResultSet("AddressBook", 
                  "FirstName, LastName, Email", 
                  "LastName='Smith'", 
                  "+FirstName"); 
  while(rs.next())
    {
    response.write(rs.FirstName + " " + 
                   rs.LastName + " " + 
                   rs.Email + "<br>");
    }

Aggregation functions may be included in the columns argument. The following example retrieves the maximum value of the UnitPrice field.

var rs = new Resultset("Products", 
  "MaxPrice = Max(UnitPrice)", "*");
if(rs.next())
   response.write(rs.MaxPrice);

SQL expressions may be included. In the following example, a SQL expression is used to add the appropriate title (Mr. or Ms.) to a name.

var rs = Resultset("AddressBook", 
"CalcFullName = CASE 
                   WHEN [SEX] = 'Male'
                     THEN 'Mr. ' + [FirstName] + ' ' + [LastName]
                   WHEN [Sex] = 'Female'
                     THEN 'Ms. ' + [FirstName] + ' ' + [LastName]", "*");
while(rs.next())
    response.write(rs.CalcFullName);