<Source>.FreeQuery (Function)

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Conditions for using <Source>.FreeQuery

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<Source>.FreeQuery (Function)

In french: <Source>.LibèreRequête

Frees the resources of a query (after the call to <Source>.ExecuteQuery or <Source>.ExecuteSQLQuery).

Note: This function is based on the <Source>.CancelDeclaration function..

When to use <Source>.FreeQuery?
This function can be used when no other process will be using the result coming from a query. We recommend that you use this function on the queries that return an important number of lines (tens of thousands) in order to free the memory space.

Example

// Initialise la requête
IF MaRequête.ExécuteRequête() = False THEN
	Error("Erreur d'initialisation de la requête" + CR + HErrorInfo())
	RETURN
END

// Lecture du premier enregistrement de la requête
MaRequête.LitPremier()
WHILE NOT MaRequête.EnDehors()
	// Traitement sur l'enregistrement de la requête
	...
	// Lecture de l'enregistrement suivant
	MaRequête.LitSuivant()
END
MaRequête.LibèreRequête()

Syntax

<Result> = <Source>.FreeQuery()

<Result>: Boolean

True if the operation was performed,
False if a problem occurs. HError is used to identify the error.

<Source>: Type corresponding to the specified source

Name of a query or a data source associated with a query (for freeing resources after the call to <Source>.ExecuteQuery or <Source>.ExecuteSQLQuery).

Remarks

Conditions for using <Source>.FreeQuery

This function must be used ONLY when the query is not required anymore!

In the following example, function <Source>.FreeQuery is used too early: the table will be completely distorted. The Table control is populated using BuildBrowsingTable in a parallel process in the background. Therefore, <Source>.FreeQuery will operate before the Table control is entirely filled, making this control unusable.

Test.ExecuteSQLQuery("select * from client")
BuildBrowsingTable(TABLE_Table1, "test")
Test.FreeQuery()

Note The problem can also occur with a variable of type "data source". A "data source" variable declared locally in a process (button click, procedure, method, etc.) ONLY exists during the execution of this code. For this reason, a "warning" is displayed if you use this type of data source: "the data source will be destroyed at the end of this code".

Component: wd300hf.dll