An NDoc Documented Class Library

HostIntegratorSession.FetchRecords Method (Int32, String)

Fetches data from the Host Integrator server for the current recordset of the current entity.

public virtual DataSet FetchRecords(
   int maxRows,
   string filterExpression
);

Parameters

maxRows
Specifies the maximum number of rows of data to be returned. If maxRows is set to 0, no limit is imposed on the number of rows returned.
filterExpression
Specifies an expression that qualifies the records to fetch. See the Remarks section for details.

Return Value

This method returns a DataSet containing the requested records. If the filterExpression eliminates all records, an empty DataSet is returned.

Remarks

The set of records returned begins with the first record following the current record. If the current record is before the first record in the recordset, searching starts with the first record. After a FetchRecords, the current record is the last record included in the returned set of records.

Using Filter Expressions

Some of the methods in the .NET connector allow you to use filter expressions when fetching records from a recordset. The syntax you can use to build filter expressions is:

condition_statement=condition_expression

You can use expressions on both the left and right sides of the condition statement. Be sure to enclose data in quotation marks.

Condition Expressions

AND condition_expression AND condition_expression
OR condition_expression OR condition_expression
NOT NOT condition_expression
Equal to value_expression = value_expression
Equal to (case insensitive) value_expression =* value_expression
Not equal to value_expression <> value_expression
Less than value_expression < value_expression
Greater than value_expression > value_expression
Less than or equal to value_expression <= value_expression
Greater than or equal to value_expression >= value_expression ( ) (multiple condition_expressions)

Value Expressions

A value expression can take any of the following:

Filter Expression Examples

This example returns all records in the patients recordset that are not "Smith":

patients.lastname  <> "Smith" 

This example returns the exact same set of records as the preceding example:

NOT (patients.lastname = "Smith")

This example returns all records in the SearchResults recordset with the last name "Smith" and first name "Steven":

(SearchResults.LastName = "Smith") and (SearchResults.FirstName =* "Steven")

This example returns all fields in the AccountNumbers recordset greater than or equal to 10000 and less than or equal to 20000:

(AccountNumbers.Accounts >= 10000) and (AccountNumbers.Accounts <= 20000)

Exceptions

Exception TypeCondition
HostIntegratorConnectorExceptionThrown when client is not connected
HostIntegratorTerminalExceptionThrown if there is an execution error
HostIntegratorModelDefExceptionThrown if the filter expression is not valid
HostIntegratorExceptionThrown if the connection is for metadata only
HostIntegratorModelDefExceptionThrown if there is no current recordset

See Also

HostIntegratorSession Class | WRQ.Verastream.HostIntegrator Namespace | HostIntegratorSession.FetchRecords Overload List