New (Recordset constructor): Difference between revisions

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<tr><th>lockstrength</th>
<tr><th>lockstrength</th>
<td>The lock strength of the instantiated <var>Recordset</var> object. Options are <var>LockStrength</var> enumeration values (<var>None</var>, <var>Share</var>, or <var>Exclusive</var>), as described below. This is an optional parameter, and it defaults to <var>Share</var>.  
<td>The lock strength of the instantiated <var>Recordset</var> object. Options are <var>LockStrength</var> enumeration values (<var>None</var>, <var>Share</var>, or <var>Exclusive</var>), as described [[#LockStrength enumeration|below]]. This is an optional parameter, and it defaults to <var>Share</var>.  
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<tr><th><var>LoopLockStrength</var></th>
<tr><th><var>LoopLockStrength</var></th>

Revision as of 22:49, 5 March 2012

Create a new Recordset object (Recordset class)


This function makes a new, empty instance of a Recordset object.

Syntax

%recordset = [%(Recordset In filOrGrp name):]New[( [lockStrength], - [LoopLockStrength= lockStrength])]

Syntax terms

%newSet An empty Recordset object created by this method.
[%(Recordset In filOrGrp name):] The optional class name in parentheses denotes a Constructor. See "Usage notes", below, for more information about invoking a Recordset Constructor.
lockstrength The lock strength of the instantiated Recordset object. Options are LockStrength enumeration values (None, Share, or Exclusive), as described below. This is an optional parameter, and it defaults to Share.
LoopLockStrength The lock strength to be used for loops on records in the Recordset object. This is an optional, name required parameter, available in Sirius Mods 7.0 and later. It defaults to None. See "LoopLockStrength for Recordsets".

LockStrength enumeration

These are the valid values of this enumeration, which correspond to standard Model 204 record-locking levels:

None
Recordset is not locked.
No locks are held on the object, so there is no conflict with others holding Share or Exclusive locks (readers and updaters may proceed). Find Without Locks statements acquire this type of record lock.
Share
Recordset is share locked.
This level allows other users to hold a Share lock, but not an Exclusive lock (allows readers but not updaters to proceed). Find All Records statements acquire this type of record lock.
Exclusive
Recordset is exclusively locked.
This level prohibits others from holding either an Exclusive lock or a Share lock. It is generally used for update. Find And Reserve statements acquire this type of record lock.

Note: As with all enumerations, the ToString method implicitly converts an enumeration value to a character string whose value is the name of the enumeration value. For more information about methods available to all enumerations, see "Common enumeration methods".

Usage notes

  • As described in "Using New or other Constructors", New can be invoked with no object, with an explicit class specification, or with an object variable in the class, even if that object is Null:

    %recset = new %recset = %(Recordset in file sirLocal):new %recset = %recset:new

    Note: As shown above, when explicitly indicating the class, both the class name and the file context must be specified just as they are on the Recordset variable's declaration.

  • Since the created Recordset object is empty, that is, contains no records, New needs to acquire no locks, so it cannot produce a record locking conflict.
  • New is typically used in conjunction with AddRecord or AddRecordset, since without these methods, the object created by New is empty and therefore fairly uninteresting.

Examples

Example New statements follow:

%rs is object recordSet in foo %rs = new %rs = new( none ) %rs = new( exclusive ) %rs = new( share )

See also