Class Reference
IRIS for UNIX 2019.2
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abstract class %Library.IResultSet extends %RegisteredObject

Interface for result sets.

A result set is a type of result returned by executing either a SELECT statement or a CALL statement. Please refer to %SQL.Statement and %SQL.StatementResult for more information on how to prepare dynamic SQL statements and how to process the results the of executing them.

Inventory

Parameters Properties Methods Queries Indices ForeignKeys Triggers
1 13 19


Summary

Properties
%Message %Metadata %PrivateTables %ROWCOUNT
%ROWID %ResultColumnCount %SQLCODE

Methods
%AddToSaveSet %ClassIsLatestVersion %ClassName %ConstructClone
%CreateSnapshot %DispatchClassMethod %DispatchGetModified %DispatchGetProperty
%DispatchMethod %DispatchSetModified %DispatchSetMultidimProperty %Display
%DisplayFormatted %Extends %Get %GetData
%GetMetadata %GetParameter %IsA %IsModified
%New %Next %NormalizeObject %ObjectModified
%OriginalNamespace %PackageName %Prepare %PrepareMetaData
%Print %RemoveFromSaveSet %ResultColumnCountGet %SendDelimitedRows
%SerializeObject %SetModified %ValidateObject

Subclasses
%Library.AbstractResultSet %Library.GTWResultSet %Library.JGWResultSet
%ResultSet.Custom %ResultSet.Result %ResultSet.SQL
%ResultSet.Static EnsLib.SQL.Snapshot

Parameters

• parameter COLUMNCOUNT;

Properties

• property %Message as %Library.String;
• property %Metadata as %Library.String(MAXLEN="") [ MultiDimensional ];
• property %PrivateTables as array of %XSQL.DS.TempTable;
%PrivateTables is an array of private temporary table orefs used by this result set subscripted by temp table name.
• property %ROWCOUNT as %Library.Integer;
• property %ROWID as %String(MAXLEN="");
• property %ResultColumnCount as %Library.Integer [ ReadOnly ];
%ResultColumnCount is the number of columns in the result set. This value is always zero unless the current result is a RESULTSET object (instance of %SQL.IResultSet) or a procedure context object (instance of %Library.IProcedureContext). For a CALL statement result, this value represents the column count of the result set currently bound. For more information on result set sequences and dynamic result set binding refer to <>.
• property %SQLCODE as %Library.Integer;

Methods

• method %CreateSnapshot(storageOffset As %Integer, ByRef lastRow As %Integer, ByRef pRuntimeMode As %Integer = "", pStatic As %ResultSet.Static = "") as %Status
%CreateSnapshot(storageOffset,lastRow) Copy all rows from the current position to the end of the cursor into a temporary global. Fetch rowCount rows into a temporary global. If the rowCount is -1 then all rows are fetched
• method %DispatchGetProperty(pProperty As %String(MAXLEN=255))
Is used to get the value of an unknown property.
• method %DispatchMethod(pMethod As %String, Args...)
Is used to implement an unknown method call. It is also used to resolve an unknown multidimensional property reference (to get the value of a property) because that syntax is identical to a method call.
• method %Display(pDelimiter As %String = " ") as %Status
alias for %Print, implement %Display for new result set interface
• method %DisplayFormatted(pFormat As %String = -1, ByRef pFileName As %String(MAXLEN="")="", ByRef pMessages As %SQL.Manager.Messages = "", ByRef pFilesUsed As %String(MAXLEN="")=0, pTranslateTable As %String(MAXLEN="")="")

Display the contents of the result object. If formatted display is available then format the results using the requested format and, if appropriate, open the formatted results using the host OS. The output is directed to one or more files and messages are placed in a result set object. All file names used are returned in an array.


Parameters


NameDescription
pFormat

The format applied to the result content. This parameter is also used to determine the file name extension.

Supported formats are:
-1%Display() format
0XML
1HTML
2PDF (requires a renderer such as FOP)
99TXT
100CSV

If pFormat is specified as any number not listed above then it will default to TXT.

pFormat can also be specified as XML, HTML, PDF, TXT or CSV.

NOTE: pFormat of CSV/100 is not a true comma separated value, but instead uses TAB separated values.

pFileName

The base file name to be used to generate actual file names used for output. If no value is specified then a file name will be generated, using the TEMP folder defined for the InterSystems IRIS instance. This value is not expected to include an extension. An extension is added to this value to form the actual file used. Also, if nested results exist then a number is appended to the file name specified to produce a unique name for each result.

pMessages

Instance of a system result set class. If no value is passed then the system message result class is instantiated. This parameter is passed by reference. It is up to the caller to process the result set oref that is returned. pMessages.Count() returns the number of messages contained in the result set. pMessages.%Display() will display the messages on the current device. pMessages.%DisplayFormatted() is also implemented and can be used to display the messages using the selected format.

pFilesUsed

This pass-by-reference parameter will contain the number of files used to display the result content and the name of each file. pFilesUsed is the number of files and pFilesUsed(file_number) is the name of the file. The sequence of the files is the same sequence as the results are processed. For simple result objects, there is a single file. For context objects that can contain result set sequences, the results are output in the order they are returned and the files used are present in pFilesUsed in that same order.

pTranslateTable

This is the translate table used for the output files when the format is CSV or TXT. This parameter is optional.


• abstract method %Get(colname As %String = "") as %Library.String
Returns the value of the column with the name name in the current row of the result set.

If name is not a valid column name, this method returns an empty string.

• abstract method %GetData(colnbr As %Integer = 0) as %Library.String
Returns the value of column colnbr in the current row of the result set.
• method %GetMetadata() as %ResultSet.MetaData
• abstract method %Next(ByRef sc As %Library.Status = $$$OK) as %Library.Integer
Advance the result set cursor to the next row. Returns 0 if the cursor is at the end of the result set.
• classmethod %Prepare(queryId As %String(MAXLEN=""), ByRef %returnError As %SYSTEM.Error, %importPackages As %RawString = "", %args...) as %Library.IResultSet
%Prepare()

This method is different for each type of result set class. This method has two tasks. First, instantiate the correct concrete result set class. Think of the first parameter, queryId, as being an "index key value" that is used to lookup the correct query implementation. For non-cached (static) queries this is simply the name of the class that implements the query, i.e. the %IResultSet interface. The second task is to prepare the resulting object for data retrieval by the caller.

  • queryId
      This can be the concrete subclass of %IResultSet that implements the desired query. For dynamic cached results this value is generally the query text that can be parsed, a hashed value computed and the cached result implementation class looked up in the query cache index.

      queryId can also be a <className><colon><queryName> or <className><colon><methodName>. If it is a <queryName> then the result set returned is an instance of %Library.ResultSet that is bound to that query. If it is the name of a method Then that method is called, passing %args... to the method, and the first result set found in the context object (%sqlcontext) is returned.

  • %returnError
      If an error occurs this is returned by reference and is a %SYSTEM.Error object with properties set to describe information about the error. %returnError.Status contains the %Status value.

  • %importPackages This is a comma delimited list of packages to import. This is only relevant if the result set implementation is generated and the query source might include unqualified names. The import packages list is used to resolve package/schema names for unqualified names.

  • %args...
      Argument values to be passed to the query/method/class %Execute() method. Zero, one or more argument values can be passed.
  • • classmethod %PrepareMetaData(queryId As %String(MAXLEN=""), ByRef returnError As %SYSTEM.Error = "", importPackages As %RawString = "") as %ResultSet.MetaData
    %PrepareMetaData is similar to %Prepare except that no result set is instantiated. This method returns an instance of %ResultSet.MetaData. Be aware that the implementation of this method might cause the result set to be instantiated but that is up to the result set class itself and no result set is actually returned by this method - only metadata.

  • queryId
      This can be the concrete subclass of %IResultSet that implements the desired query. For dynamic cached results this value is generally the query text that can be parsed, a hashed value computed and the cached result implementation class looked up in the query cache index.

      queryId can also be a <className><colon><queryName> or <className><colon><methodName>. If it is a <queryName> then the metadata is retrieved from the compiled query. If it is the name of a method then no metadata can be prepared since it requires the method to be executed.

  • returnError
      If an error occurs this is returned by reference and is a %SYSTEM.Error object with properties set to describe information about the error. returnError.Status contains the %Status value.

    • importPackages This is a comma delimited list of packages to import. This is only relevant if the result set implementation is generated and the query source might include unqualified names. The import packages list is used to resolve package/schema names for unqualified names.

  • • method %Print(pDelimiter As %String = " ") as %Status
    %Print()

    Write the current row to the current device. An optional column delimiter can be specified. No formatting is applied other than writing pDelimiter between column values. This can be useful for exporting result set data to tab delimited files.

    For example:

    	set sql = "select name,home_street,home_city,home_state,home_zip from sample.person"
    	set rset = ##class(%ResultSet.SQL).%Prepare(.sql,.err,"")
    	if '$Isobject(err) {
    		set file="c:\temp\names.asv"
    		open file:"WNS"
    		use file while rset.%Next() { do rset.%Print($char(9)) } 
    		close file
    	}

    Example data:
    Cornell,Ezra M.340 Franklin CourtSarasotaNY12866
    Huff,Stephen A.548 Washington BlvdBrownfield CenterMD53436
    Sands,Jeep Q.7298 Washington DriveXavierWY23685

    • method %ResultColumnCountGet() as %Integer
    This is a Get accessor method for the %ResultColumnCount property.
    • abstract method %SendDelimitedRows(pMaxRows As %Integer = 0, pDelimiter As %String = "", ByRef pReturnCount As %Integer = 0) as %Status
    Fetch and send a series of rows for continuous query client. For internal use only.


    Copyright (c) 2019 by InterSystems Corporation. Cambridge, Massachusetts, U.S.A. All rights reserved. Confidential property of InterSystems Corporation.