Tài liệu Module 9: Using Calculated Cells pdf

Contents Overview 1 Using Calculated Cells 2 Lab A: Creating a Calculated Cells Formula 17 Review 20 Module 9: Using Calculated Cells BETA MATERIALS FOR MICROSOFT CERTIFIED TRAINER PREPARATION PURPOSES ONLY Information in this document is subject to change without notice. The names of companies, products, people, characters, and/or data mentioned herein are fictitious and are in no way intended to represent any real individual, company, product, or event, unless otherwise noted. Complying with all applicable copyright laws is the responsibility of the user. No part of this document may be reproduced or transmitted in any form or by any means, electronic or mechanical, for any purpose, without the express written permission of Microsoft Corporation. If, however, your only means of access is electronic, permission to print one copy is hereby granted. 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The names of companies, products, people, characters, and/or data mentioned herein are fictitious and are in no way intended to represent any real individual, company, product, or event, unless otherwise noted. Other product and company names mentioned herein may be the trademarks of their respective owners. Module 9: Using Calculated Cells iii BETA MATERIALS FOR MICROSOFT CERTIFIED TRAINER PREPARATION PURPOSES ONLY Instructor Notes In this module, students learn how to work with calculated cells in Microsoft ® SQL Server ™ 2000 Analysis Services. Calculated cells are a method of applying multidimensional expressions (MDX) in an extremely sophisticated fashion within a cube. In addition, the module reviews how calculated cells differ from calculated members and custom member formulas. After completing this module, students will be able to: ! Retrieve revenues from the Sales cube by using the LookupCube function. Materials and Preparation This section provides you with the required materials and preparation tasks that are needed to teach this module. Required Materials To teach this module, you need the following materials: ! Microsoft PowerPoint ® file 2093A_09.ppt Preparation Tasks To prepare for this module, you should: ! Read all of the materials for this module. ! Read the instructor notes and margin notes. ! Practice the lecture and demonstration. ! Complete the labs. ! Review the Teacher Preparation materials on the Teacher Preparation compact disc. Presentation: 45 Minutes Labs: 15 Minutes iv Module 9: Using Calculated Cells BETA MATERIALS FOR MICROSOFT CERTIFIED TRAINER PREPARATION PURPOSES ONLY Instructor Setup for Group Activities and Labs This section provides setup instructions that are required to prepare the instructor computer or classroom configuration for group activities and labs. All group activities and labs use the same database setup, which requires restoring a database archive. ! To prepare for group activities and labs In this procedure, you restore the Market database, which is a .cab file type. 1. Start Analysis Manager. 2. In the left pane, expand the Analysis Services folder. 3. Expand the Server icon and verify that the Market database does not exist. 4. Right-click the Server icon, and then click Restore Database. 5. Navigate to the C:\Moc\2093A\Batches folder. 6. Select Market.cab, click Open, and then click Restore. If the Market database already exists from a previous group exercise or lab, and cubes within the database contain extraneous information, you can return the Market database and its cubes to a beginning position by either: Deleting any calculated members that were created in a specific cube, and then saving the cube. - or - Repeating the preceding restore database procedure. Module 9: Using Calculated Cells v BETA MATERIALS FOR MICROSOFT CERTIFIED TRAINER PREPARATION PURPOSES ONLY Other Activities Difficult Questions The following list presents several difficult questions that students may ask you during the delivery of this module and answers to the questions. These materials delve into subjects that are in the scope of the module but may not be specifically addressed in the content of the student notes. 1. Can the LookupCube function retrieve a value from a different database? No. The cube must be in the same database. If you use linked cubes, you can technically get values from a cube that is on another server, but it still must be linked to the same cube. 2. Do you have to process a cube after adding a custom member formula? Generally, yes. If the dimension is shared, write-enabled, or parent- child—then you do not need to process the cube after adding a custom member formula. Otherwise, if the dimension is private, not write- enabled, or not parent-child, you must perform an incremental update on the dimension and process the cube using at least the refresh option. 3. Can a custom member formula refer to the value of a calculated member? Yes. A custom member formula can use any MDX expression that is meaningful in the context of the cube. 4. Can a LookupCube formula refer to the parent of the current member? Yes, but it won’t happen automatically. In order to use the Parent function—or some other member function—you must construct a string that pieces together the unique name of the member with the rest of the tuple. 5. What limitations are there on the MDX expression you can use in calculated cells? You can use any MDX expression that is meaningful in the context of the cube. 6. Is there any way to integrate a calculated member into the aggregation of a cube? Not easily, but you could create a custom rollup formula that refers to the calculated member. vi Module 9: Using Calculated Cells BETA MATERIALS FOR MICROSOFT CERTIFIED TRAINER PREPARATION PURPOSES ONLY Module Strategy Major sections of this module begin with or include a group activity followed by review lecture and then labs. The following are guidelines for delivering materials in the context of group activities: ! Using group activities to introduce new content You often introduce new concepts or functionality while delivering the procedures in a group activity as a live demonstration. For example, you may present a new MDX function by showing first its construction and then its result set as an actual calculated member formula or in a query statement. Use the topic slides that follow the group activity as a review of the content—for example, the syntax of a specific function. ! Interaction with students A group activity flows best when you deliver it as a shared exploration. Ask students such questions as: “What would happen if we…?” “Why did this happen?” “Was that what you expected?” Encourage students to ask you questions about the functions being tested. ! Students follow along In some cases, you may want to encourage students to follow your live demonstration on their own computers. This practice works best for simpler group activities or for a group activity that is not replicated by a later lab. It is not a problem if a student does not follow your demonstration, or if a student starts following and then stops before the group activity is completed. There is no file or structure dependency between group activities or between a group activity and a later lab. ! Lab replication of group activity The exercises in the labs closely follow the group activity procedures but do not define each step or show the code answer. Encourage students to write and test the MDX expressions on their own, referring back to the group activity procedures for clarification. Students may also refer to answer files, which are available for each procedure in an exercise. Labs are generally more challenging when students have not followed the instructor on their own computers during the group activity. However, many students benefit from the two hands-on experiences of following the group activity and then completing the labs. ! Answer files for group activities Where applicable, answer files are provided for each procedure in group activities. If necessary to facilitate your demonstration, copy and paste the correct expression from the answer file into the Calculated Member Builder. Use the following additional strategies to present this module: ! Using Calculated Cells Teach how to use the LookupCube function, which retrieves a value from a different cube. Then review calculated value types, comparing them with calculated members, custom members, and calculated cells. Further explain the member source and formula scope for calculated members, custom members and calculated cells. Module 9: Using Calculated Cells 1 BETA MATERIALS FOR MICROSOFT CERTIFIED TRAINER PREPARATION PURPOSES ONLY Overview ! Using Calculated Cells In this module, you will learn how to work with calculated cells in Microsoft ® SQL Server ™ 2000 Analysis Services. Calculated cells are a method of applying multidimensional expressions (MDX) in an extremely sophisticated fashion within a cube. In addition, the module reviews how calculated cells differ from calculated members and custom member formulas. After completing this module, you will be able to: ! Retrieve revenues from the Sales cube by using the LookupCube function. Topic Objective To provide an overview of the module topics and objectives. Lead-in In this module, you will learn about calculated cells and how to use them. 2 Module 9: Using Calculated Cells BETA MATERIALS FOR MICROSOFT CERTIFIED TRAINER PREPARATION PURPOSES ONLY # ## # Using Calculated Cells ! Group Activity: Creating a Custom Member Formula ! Group Activity: Creating a Calculated Cells Formula ! LookupCube Function ! Calculated Value Types ! Member Source ! Formula Scope In this module, you will work in the Finance cube, which calculates the income statement for a fictional company. The cube includes both Actual and Budget values. You will work specifically with the Revenue account. For Budget values, Revenue is stored in the Finance cube. To minimize the risk of inconsistent data, Actual values are stored in the Sales cube under the member name Sales Dollars. The objective is to report on Revenue for Actual values in the Finance cube, retrieving data from the Sales cube. The group activities introduce the use of a custom member formula to provide special handling for an entire member and the use of a custom cell formula to provide special handling for any number of specified members. The following topics follow the two group activities: ! LookupCube Function This topic describes how to use the LookupCube function, which retrieves a value from a different cube. ! Calculated Value Types This topic summarizes the key differences among calculated members, custom member formulas, and calculated cells. ! Member Source This topic provides more detail about one of the key difference between types of calculated values—the source of the members that use the formula. ! Formula Scope This topic provides more detail about the other key difference between types of calculated values—the scope of the formula. Topic Objective To introduce the first problem for the module— how to retrieve selected values from a different cube. Lead-in In addition to creating calculated members in a cube, you can create dynamic or temporary calculated members in an MDX query statement. Delivery Tip Briefly explain the bullets on this diamond slide to provide context for the upcoming group activity in which the items are functionally demonstrated. Module 9: Using Calculated Cells 3 BETA MATERIALS FOR MICROSOFT CERTIFIED TRAINER PREPARATION PURPOSES ONLY Group Activity: Creating a Custom Member Formula In this group activity, you may follow along on your own computer with your instructor or observe the demonstration. You will learn how to create a custom member formula to look up the Actual values for Revenue from the Sales cube. ! To review existing Revenue values in the Finance cube In this procedure, you browse the data in the Revenue member of the Account dimension. 1. In the Analysis Manager, open the Market database, right-click the Finance cube, click Edit, and then click the Data tab. The Finance cube contains the following three dimensions: • The Scenario dimension contains the members Actual and Budget. • The Time.Calendar dimension contains calendar years, quarters, and months. • The Account dimension is a parent-child dimension that includes an income statement hierarchy. In this section, you will focus on the Revenue member of the Account dimension. For the Actual scenario, the Revenue value should come from the Sales cube. For the Budget scenario, the Revenue value is stored in the fact table. Start by looking at the Revenue value for the Budget scenario. Topic Objective To learn the use of a custom member formula to provide special handling for a member. Lead-in Let us see what happens when we create a custom member formula to look up the Actual Revenue value from the Sales cube. Delivery Tip Important: This section does not have a lab that follows it. It is intended as a review of administrative material that the students should already have been exposed to. If students are not familiar with custom member formulas, you may want to proceed slowly and encourage them to follow along in the group activity. 4 Module 9: Using Calculated Cells BETA MATERIALS FOR MICROSOFT CERTIFIED TRAINER PREPARATION PURPOSES ONLY 2. In the Scenario dimension drop-down list, click the Budget scenario, and then expand the Net Profit node and the Gross Profit node. The Revenue value for All Time is 91,200. This is the sum of all the monthly budgets over 1997 and 1998. Revenue values for Budget were generated during the same planning process as all the other budget numbers and were then loaded into the cube from the fact table when the cube was processed. 3. In the Scenario dimension list, click the Actual scenario. The Revenue value is blank. Revenue for the Actual scenario are not stored in the same fact table as the balance of the financial information, but they can be derived from the Sales cube. The Revenue member is simply one member of the Account dimension. It requires special handling—that is, you must treat it differently from the other members. You can use the LookupCube function to retrieve the revenue values from the Sales cube, but Revenue is the only member that should use the LookupCube function. One way to treat a single member differently from the rest of the dimension is to use a custom member formula. With a custom member formula, the formula for a single member can be stored in the dimension table. In the Account dimension table, there is already a column that contains the appropriate formula for the Revenue member. [...]... define calculated cells, which is reviewed in the next group activity BETA MATERIALS FOR MICROSOFT CERTIFIED TRAINER PREPARATION PURPOSES ONLY Module 9: Using Calculated Cells 9 Group Activity: Creating a Calculated Cells Formula Topic Objective To learn the use of a calculated cells formula to provide special handling for a member in a single scenario Lead-in Let us see what happens when we create a calculated. .. This automatically selects the new bottom calculated member 4 Repeat step 3 until all calculated members are removed 5 Save and close the Finance cube BETA MATERIALS FOR MICROSOFT CERTIFIED TRAINER PREPARATION PURPOSES ONLY Module 9: Using Calculated Cells 19 ! To create a calculated cells formula In this procedure, you create a calculated cells formula by using the LookupCube function LookupCubefunction.txt... LookupCube("Sales","[Sales Dollars]") Note The formula for calculated cells is the same as the one for the custom member formula BETA MATERIALS FOR MICROSOFT CERTIFIED TRAINER PREPARATION PURPOSES ONLY Module 9: Using Calculated Cells 11 2 Click Next, when prompted for a name for the calculated cells, type Revenue and then click Finish The name you give the calculated cells expression is for your convenience It does... the Finance cube 2 In the Cube tree in the left pane, right-click the Calculated Cells folder, and then click New Calculated Cells 3 Use the Calculated Cells Wizard to create a new calculated cells expression named Revenue that retrieves the Sales Dollars value from the Sales cube by using the LookupCube function The calculated cells expression should apply only to the Amount measure and to the Budget... TRAINER PREPARATION PURPOSES ONLY 14 Module 9: Using Calculated Cells Calculated Value Types Topic Objective To explain the difference between common types of cells ! Cube Values Come from Fact Table or Are Calculated Lead-in ! Calculated Values Come in Three Varieties The value in a cell can come from the fact table or from a calculation Formula Scope Member Source Calculated Members Member Calculation... completed modules 1 through 8 in course 2093A, Implementing Business Logic with MDX in Microsoft® SQL Server™ 2000 Estimated time to complete this lab: 15 minutes BETA MATERIALS FOR MICROSOFT CERTIFIED TRAINER PREPARATION PURPOSES ONLY 18 Module 9: Using Calculated Cells Exercise 1 Creating a Calculated Cells Formula In this exercise, you will use the LookupCube function to create a calculated cells formula... the following table BETA MATERIALS FOR MICROSOFT CERTIFIED TRAINER PREPARATION PURPOSES ONLY 20 Module 9: Using Calculated Cells Review Topic Objective To reinforce module objectives by reviewing key points ! Using Calculated Cells Lead-in The review questions cover some of the key concepts taught in the module 1 What is unusual about the arguments of the LookupCube function? They are both string values,... PREPARATION PURPOSES ONLY Module 9: Using Calculated Cells 15 Member Source Topic Objective To clarify the implications of member source Lead-in ! A calculated member creates a new member that does not exist in the original dimension definition Calculation Calculated Members $ $ ! Creates completely new member Is not included in rollups Dimensions—Custom Members and Calculated Cells $ Replaces definition... dimensions You can create a calculated cells formula that applies only to the Budget scenario for descendants of Bread in the year 1998 A subcube allows you to create sophisticated formulas without a complex and unwieldy IIF function BETA MATERIALS FOR MICROSOFT CERTIFIED TRAINER PREPARATION PURPOSES ONLY Module 9: Using Calculated Cells 17 Lab A: Creating a Calculated Cells Formula Topic Objective... create a calculated cells expression that applies to only a portion of the cube In this procedure, you create a calculated cells expression that applies only to a portion of the cube 1 In the Analysis Manager, open the Market database, edit the Finance cube, and then set the right pane to preview data 2 In the Cube tree in the left pane, right-click the Calculated Cells folder, click New Calculated Cells, . Contents Overview 1 Using Calculated Cells 2 Lab A: Creating a Calculated Cells Formula 17 Review 20 Module 9: Using Calculated Cells BETA MATERIALS. member source and formula scope for calculated members, custom members and calculated cells. Module 9: Using Calculated Cells 1 BETA MATERIALS FOR MICROSOFT