Tài liệu Beginning SQL Server Modeling- P4 pdf

CHAPTER 3  DOMAIN-SPECIFIC LANGUAGES 101: LOLA’S LUNCH COUNTER 61 and execute another dir command to be sure the compiler created the LunchCounter.mx image file (see Figure 3-35). Figure 3-35. SQL compiling the LunchCounter.mg file to create the LuncCounter.mx image file Next, you want to use the DSL Grammar executor command-line tool to generate an M code version of the SandwichLanguage.dsl file. (The executable was formerly called the Mgrammar executor, which is where it got its mgx.exe name.) With any executable command-line tool, you can normally enter the name of the command followed by /? to get a listing of the parameters that can be used to pass information to the tool when it executes. Figure 3-36 shows a list of these parameters. The two you’re interested in are reference and MModuleName. (Note that most, but not all, have shorthand aliases, like /r: for /reference:, to save you time when you’re using the tool frequently.) Download from Wow! eBook <www.wowebook.com> CHAPTER 3  DOMAIN-SPECIFIC LANGUAGES 101: LOLA’S LUNCH COUNTER 62 Figure 3-36. Displaying the MGX tool parameters At the command prompt, enter and execute the command as follows: Mgx.exe SandwichLanguage.dsl /reference:LunchCounter.mx /MModuleName: LunchCounter Figure 3-37 shows this, except that I’ve used aliases for setting the parameters to keep the command from wrapping in the command window. You can try it either way. If you do a dir directory listing, you can see that this command created the SandwichLanguage.m file. Download from Wow! eBook <www.wowebook.com> CHAPTER 3  DOMAIN-SPECIFIC LANGUAGES 101: LOLA’S LUNCH COUNTER 63 Figure 3-37. Running the MGX MGrammar executor tool to generate the SandwichLanguage.m file Loading this file into Intellipad (see Figure 3-38), you can see that it is an M Graph almost exactly the same as the one generated earlier when you made the final revisions to the DSL Grammar code prior to setting up for the deployment phase. The one difference is that the graph is now defined within the LunchCounter module. Download from Wow! eBook <www.wowebook.com> CHAPTER 3  DOMAIN-SPECIFIC LANGUAGES 101: LOLA’S LUNCH COUNTER 64 Figure 3-38. Displaying SandwichLanguage.m in Intellipad M Graph mode You should be ready for the last step of installing the schema and instances to the database. You can do this with the mx.exe executor tool. The MSchema file, LunchCounter.Schema.m, defines the four types and extents that the M Graph uses: SandwichOrders, Breads, Stuff, and Condiments. The MSchema file tells the SQL Server Modeling framework how to store the instances of the data represented in the M Graph in a data store. With your MSchema defined, you can use both the M Graph created by the MExecutor (mgx.exe) and the MSchema (LunchCounter.Schema.m, as shown in Figure 3-32) to compile your M files for use in a SQL Server data store by using the M compiler: m.exe SandwichLanguage.m LunchCounter.Schema.m /t:TSql10 The /t: target flag specifies that the output will be used for deploying the schema and instances. The result of executing this command is the image file SandwichLanguage.mx. (See the listing generated by the dir command in Figure 3-39.) Download from Wow! eBook <www.wowebook.com> CHAPTER 3  DOMAIN-SPECIFIC LANGUAGES 101: LOLA’S LUNCH COUNTER 65 Figure 3-39. Generating the SandwichLanguage.mx image file You can also add a package flag (/p) to specify that instead of an image file, you want a SQL script: m.exe SandwichLanguage.m LunchCounter.Schema.m /t:TSql10 /p:Script This generates the SQL script file SandwichLanguage.sql (see Figure 3-40). Figure 3-40. Generating the SandwichLanguage.sql script file with the m.exe compiler You can run this script as a query in SQL Server Management Studio (SSMS) to load the database. Bring up SSMS, click on the File menu, then Open  File (see Figure 3-41). Download from Wow! eBook <www.wowebook.com> CHAPTER 3  DOMAIN-SPECIFIC LANGUAGES 101: LOLA’S LUNCH COUNTER 66 Figure 3-41. Opening the generated SQL script file in SQL Server Management Studio When the Open File dialog box appears, browse to the C:\LunchCounter folder and select the SandwichLanguage.sql. To open it, either double-click the file or click the Open button. This will display the contents of the T-SQL script file. Click the Execute button on the SSMS toolbar, as shown in Figure 3-42. Figure 3-42. SQL Server Management Studio after opening the SandwichLanguage.sql T-SQL script file Download from Wow! eBook <www.wowebook.com> CHAPTER 3  DOMAIN-SPECIFIC LANGUAGES 101: LOLA’S LUNCH COUNTER 67 An alternative approach to deploying the database is to use the mx.exe command-line utility. Figure 3-43 displays the syntax for using the mx.exe tool to deploy to the database, along with the output generated. Figure 3-43. SQL installing the LunchCounter database using the MX executor Regardless of which way you decide to deploy the LunchCounter module, you can check the installation by bringing up SQL Server Management Studio. If it is already up, simply click the server connection and press the F5 key to refresh the display. You should now see LunchCounter displayed as one of the databases under the Databases list. Expand LunchCounter, then click on Tables. (Figure 3-44 shows a partial view of the LunchCounter database Tables list.) Scroll down the list until you get to where the LunchCounter tables should appear. You should see four tables listed: • LunchCounter.Breads • LunchCounter.Condiments • LunchCounter.SandwichOrders • LunchCounter.Stuffs You can examine the data in each of these tables by right-clicking on the table name and selecting Edit Top 200 Rows. Download from Wow! eBook <www.wowebook.com> CHAPTER 3  DOMAIN-SPECIFIC LANGUAGES 101: LOLA’S LUNCH COUNTER 68 Figure 3-44. Checking the LunchCounter database Tables list in SSMS Before reviewing the data in the tables, let’s recall the four sample orders you set up in your SandwichLanguage.dsl file. The final Intellipad split-pane view (refer to Figure 3-31) shows these. They consisted of the following: • Order 1: Pastrami on Rye with Lettuce & Tomato. • Order 2: Ham on 9-Grain Wheat with Mayo and Mustard. • Order 3: Spam on White with Salsa. • Order 4: Grilled Tofu & Portabella in Pita with Lettuce. These should be reflected in the four LunchCounter database tables. Note that there are three many-to-one relationships in these orders: two condiments in Orders 1 and 2, and two stuffs in Order 4. The tables should reflect these. Figure 3-45 shows the four instances of SandwichOrder in the SandwichOrders table. This table contains the order keys only, since all the remaining data of an order (the Bread, Stuffs, and Condiments values) are reflected in the three other tables. If Lola and Norm get into further design iterations and refinements, the SandwichOrders table might contain other data, such as an Order timestamp. But for now, each instance in the table has only a key, reflected as a foreign key in each of the Breads, Condiments, and Stuffs tables. Download from Wow! eBook <www.wowebook.com> CHAPTER 3  DOMAIN-SPECIFIC LANGUAGES 101: LOLA’S LUNCH COUNTER 69 Figure 3-45. The SandwichOrders table, which contains only the order key Figure 3-46 shows the Breads table. Note that there is only one Bread value for each order, which is what you would expect, since this is how the orders were set up in the sample DSL file. Besides, one Bread per SandwichOrder is a business rule that was reflected in the LunchCounter.Schema.m file. Figure 3-46. The Breads table Figure 3-47 shows the Condiments table, and you can see there are two one-to-many relationships: Order1 has two condiments (Lettuce and Tomato) and Order 2 also has two condiments (Mayo and Mustard). This is as you would expect, given the sample orders in the DSL file. Download from Wow! eBook <www.wowebook.com> CHAPTER 3  DOMAIN-SPECIFIC LANGUAGES 101: LOLA’S LUNCH COUNTER 70 Figure 3-47. The Condiments table Finally, Figure 3-48 shows the values in the Stuffs table, which includes a single many-to-one relationship: Order 4 has two Stuff values (Grilled Tofu and Portabella). Again, this is confirmed by the expression of the fourth order in the list: Grilled Tofu & Portabella in Pita with Lettuce. So the database instances appear to be entirely consistent with the model. Figure 3-48. The Stuffs table You may have notice that under the LunchCounter database item in the Object Explorer pane of SSMS is an item called Database Diagrams. Let’s see if you can generate a diagram of the five tables. Click on the Database Diagrams item, and you will more than likely get a message window like that shown in Figure 3-49, asking if you would like to generate the support objects required to use database diagramming. Click the Yes button to generate the support objects. Download from Wow! eBook <www.wowebook.com> Download from Wow! eBook <www.wowebook.com> [...]... tables and their relationships Diagramming is a powerful tool in SQL Server, and there is a lot of functionality provided in the diagramming tools Covering these features is beyond the scope of this book, but I hope I’ve provided at least a taste of how the SQL Server Modeling tools can be used in conjunction with the traditional SQL Server tools (such as SSMS and Visual Studio) to create and deploy... sample Thinking Ahead You could continue refining your model for SandwichOrders, and more generally the functionality of your system Here are a few possibilities: • Tag each order with a timestamp, the server s name, and the table number • Track inventory effects by decrementing the respective quantities in inventory for each order served • Extend the DSL to a broader range of orders, like drinks, salads,... way, by both the domain expert and the technology expert There is a minimum of, if any, arcane rules of syntax to learn and remember • Simplicity (remember the lack of expressiveness I mentioned at the beginning? ): This goes hand-in-hand with the first two attributes Readability and write-ability won’t be attained without simplicity 79 Download from Wow! eBook Download from Wow! eBook . you want a SQL script: m.exe SandwichLanguage.m LunchCounter.Schema.m /t:TSql10 /p:Script This generates the SQL script file SandwichLanguage .sql (see Figure. toolbar, as shown in Figure 3-42. Figure 3-42. SQL Server Management Studio after opening the SandwichLanguage .sql T -SQL script file Download from Wow! eBook