![]() In order for a user to be able not only to select a value but also to enter it, it is necessary to set the Allow User Values parameter in the variable editor. In this case, when viewing a report, a user will be able to select a value of the variable. In order for a variable to be with a request for a value from a user, in the variable editor, check the box next to the Request from User parameter. Secondly, a report variable can be with a value query from a user (input or selection) or simply return a value. At the same time, a simple Parameter object can be used only in the data source in which it is created. First of all, you can create one report variable and use it in queries for various data sources. Using a variable as a parameter in a query has several advantages over using the Parameter object. Next, you should specify a variable name in the query text. Explicitly using of a report variable as a parameter in a query means setting the Allow using as SQL parameter option in the form of variable edit. Implicitly means creating the Parameter object in the query form and specifying a link to a report variable as an expression of this parameter. A reference to a report variable can also be specified as an expression.Ī report variable can be used in a query explicitly or implicitly. Firstly, the first parameter (the uppermost on the parameters panel in the query form) will be used in the query text, then the second (i.e., the second in the list) and further along with the parameters list in the top-down direction.Īn expression of the parameter can be both any value and an expression that will result in a filtering value. If named parameters are supported, in this case, parameters in a query are referred to sequentially. Don’t forget that if a data storage type supports named parameters, they are referred to in the query text by the parameter's name. You can learn more about this in the specifications of your data storage. Important to know!Ī query can use named and unnamed parameters. The parameter is specified in query text according to the syntax used for a particular type of data storage. Added parameters in the form of a query will be displayed in the report data dictionary and may be edited at any moment of report creation. The calculation result will be a filtering value of the current parameter. After creating the parameter using its properties, you can define a data type, size, name, and an expression. There is the New Parameter control to create this object as a query. When creating or editing a query in the form of queries, you can create the Parameter object that will be used in a query. All this indicates the advantages of using parameters in a fetch query. This is due to the fact that other external factors exert influence over the speed of execution of the query - from technical characteristics of the server where the database is deployed to maintaining a stable connection to that server. So, the time of getting data from storage can considerably increase the time of their processing by the report generator. However, it will not reduce the time to execute a query. But, it allows you to display only necessary data in the viewer. You can define filters for elements and components and use data transformation, etc. Our products contain data filtration by the engine of the report generator. Since the size of filtered data will be less than the size of all data in storage, they will be processed by the report generator and displayed in the viewer much faster. After processing a query for selection, only the data that is directly required to be used in a report or dashboard will be returned. This, of course, is mainly about SQL data storage, such as MS SQL, MySQL, Oracle, etc.Īs a rule, filtering aims to reduce the size of data transferred from storage to the report writer. Before we proceed to detailed analysis, let us remind you that, in most cases, it’s possible to specify a filtering parameter to a data storage in queries. In addition, we’ll tell you about the capabilities of report creators when creating a report and a dashboard. In today’s article, we’re going to tell you about features of data filtering when querying storage and how to reduce time for it, having optimized the process of report and dashboard rendering.
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