Query Class Reference

Inheritance diagram for Query:

Static Public Member Functions
_.Library.Status	Close (_.Library.Binary qHandle)
	Close the query. More...
_.Library.Status	Execute (_.Library.Binary qHandle)
	Executes the query; This method is called with the query input parameters. More...
_.Library.Status	Fetch (_.Library.Binary qHandle, _.Library.List Row, _.Library.Integer AtEnd)
	Fetch the next row of data from the query. More...
_.Library.Status	FetchRows (_.Library.Binary qHandle, _.Library.Integer FetchCount, _.Library.List RowSet, _.Library.Integer ReturnCount, _.Library.Integer AtEnd)
	FetchRows returns the next FetchCount rows in the query and updates handle for subsequent operations. More...
_.SQL.StatementResult	Func ()
	Func is a method that is used to invoke the query as a function, returning an instance of SQL.StatementResult.
_.Library.Status	GetInfo (_.Library.List colinfo, _.Library.List parminfo, _.Library.List idinfo, _.Library.Binary qHandle, _.Library.Integer extoption, _.Library.List extinfo)
	Returns information about the query. More...
_.Library.Status	Prepare (_.Library.Binary qHandle, _.Library.String statement, _.Library.Integer containid, _.Library.String optional)
	Prepare the query for execution. More...
	SendODBC (_.Library.Binary qHandle, _.Library.String array, _.Library.Integer qacn, _, _.Library.Integer qrc, _.Library.Boolean piece, _.Library.Integer ColumnCount)
	Fetch and send a series of rows for the ODBC/JDBC server. More...

Static Public Attributes
	CONTAINID = None
	SELECTMODE = None
	The SELECTMODE parameter allows the query author to declare the format of the values returned by the query. More...

Detailed Description

For information on this class, see Defining and Using Class Queries.

The Query class defines the basic interface used by class queries.

Use the Query class as a type for a class query if you wish to implement the query using custom-written ObjectScript.

Member Function Documentation

Close()

_.Library.Status Close ( _.Library.Binary  qHandle )

static

Close the query.

qHandle is user-defined data.

Reimplemented in DynamicSQLQuery, and DynamicGWQuery.

Execute()

_.Library.Status Execute ( _.Library.Binary  qHandle )

static

Executes the query; This method is called with the query input parameters.

qHandle is user-defined data used to communicate amongst the various Query methods.

Reimplemented in DynamicSQLQuery, DynamicObjectQuery, and DynamicGWQuery.

Fetch()

_.Library.Status Fetch ( _.Library.Binary  qHandle, _.Library.List  Row, _.Library.Integer  AtEnd  )

static

Fetch the next row of data from the query.

qHandle is query-defined data and is typically updated by Fetch.

The Fetch method should set Row to be a $List of values corresponding to the columns of the query. If we are past the end of the data and no row is returned, Row should be set to null string (""). If the non-empty row being returned is the last one, AtEnd could be optionally set to 1, indicating that an additional call to Fetch may be avoided.

Row may also be subscripted. If any of the columns in the row are stream orefs then the oref type information is lost in the Row $list encoded value. To retain the oref type, place the oref into Row(0,columnNumber). Library.ResultSet recognizes this form and will extract the column value as the subscripted value.

Reimplemented in DynamicSQLQuery, DynamicObjectQuery, and DynamicGWQuery.

FetchRows()

_.Library.Status FetchRows ( _.Library.Binary  qHandle, _.Library.Integer  FetchCount, _.Library.List  RowSet, _.Library.Integer  ReturnCount, _.Library.Integer  AtEnd  )

static

FetchRows returns the next FetchCount rows in the query and updates handle for subsequent operations.

FetchCount is the number of rows to fetch. If FetchCount is zero then up to 24k of row data is returned. ReturnCount contains the number of rows returned and AtEnd is true if there are no more rows to be fetched. This method does not preserve swizzled streams.

Reimplemented in DynamicSQLQuery, and DynamicObjectQuery.

GetInfo()

_.Library.Status GetInfo ( _.Library.List  colinfo, _.Library.List  parminfo, _.Library.List  idinfo, _.Library.Binary  qHandle, _.Library.Integer  extoption, _.Library.List  extinfo  )

static

Returns information about the query.

It is used by the various ResultSet objects.

Returns information about columns in the query result, parameters in the query formal list, and whether or not the result contains enough information to form an ID value.

This information is return in three pass-by-reference parmeters:

• colinfo - contains one list element for each column declared in ROWSPEC. The form is name:exttype:caption
• parminfo - contains one list element for each formal paramter of the query in the form name:exttype
• idinfo - contains a list, the first element indicating the position of the ID, zero if not included and the second element is the extent of these ID value.
• qHandle - <Optional> query handle, used for dynamic queries

Reimplemented in DynamicSQLQuery, and DynamicGWQuery.

Prepare()

_.Library.Status Prepare ( _.Library.Binary  qHandle, _.Library.String  statement, _.Library.Integer  containid, _.Library.String  optional  )

static

Prepare the query for execution.

For static queries, this method probably just

returns $$$OK. For dynamic queries this method will set up the information returned by GetInfo. It is used by the various ResultSet objects.

Reimplemented in DynamicSQLQuery, DynamicGWQuery, and DynamicObjectQuery.

SendODBC()

SendODBC ( _.Library.Binary  qHandle, _.Library.String  array, _.Library.Integer  qacn,   _, _.Library.Integer  qrc, _.Library.Boolean  piece, _.Library.Integer  ColumnCount  )

static

Fetch and send a series of rows for the ODBC/JDBC server.

For internal use only.

Member Data Documentation

CONTAINID

CONTAINID = None

static

For information on this class, see Defining and Using Class Queries.

The Query class defines the basic interface used by class queries.

Use the Query class as a type for a class query if you wish to implement the query using custom-written ObjectScript.

SELECTMODE

SELECTMODE = None

static

The SELECTMODE parameter allows the query author to declare the format of the values returned by the query.

It is the responsibility of the query implementation to properly format the values according to the SELECTMODE value. If SELECTMODE is RUNTIME then the query implementation has to examine the current runtime setting and react accordingly. The current runtime SELECTMODE value can be retrieved by calling $system.SQL.GetSelectMode(). The default value of SELECTMODE is LOGICAL to preserve compatibility with older implementations. REMEMBER - it is only a declaration and the implementation of the query is responsible for properly formatting the column values in a manner consistent with the SELECTMODE setting.