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Wiki source code of 16 Annex 6: Worked Use Case

Version 10.1 by Artur on 2025/05/27 17:43
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Artur 1.1 1 {{box title="**Contents**"}}
2 {{toc/}}
3 {{/box}}
4
5 == 16.1 Scope ==
6
Helena 4.1 7 The scope of this Chapter is to show the [[SDMX-ML>>doc:sdmx:Glossary.SDMX-ML.WebHome]] interactions with the Registry, database, and [[metadata repository>>doc:sdmx:Glossary.Metadata repository.WebHome]] for the use case scenario outlined in Chapter 3. The scenario is repeated below.
Artur 1.1 8
Helena 4.1 9 The [[SDMX-ML>>doc:sdmx:Glossary.SDMX-ML.WebHome]] examples used are (% style="color:#e74c3c" %)version(%%) 2.1.
Artur 1.1 10
11 == 16.2 Scenario ==
12
Helena 4.1 13 This scenario is the dissemination of data and related [[reference metadata>>doc:sdmx:Glossary.Reference metadata.WebHome]] using [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] web services. It shows how the data, [[reference metadata>>doc:sdmx:Glossary.Reference metadata.WebHome]], and [[structural metadata>>doc:sdmx:Glossary.Structural metadata.WebHome]] are used to build a web dissemination system.
Artur 1.1 14
15 [[image:image-20250318221512-1.jpeg||data-xwiki-image-style-alignment="center"]]
16
17 (% style="text-align: center;" %)
Helena 4.1 18 **{{id name="image_47"/}}Figure 47: Process flow of an [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] Web Data Dissemination System**
Artur 1.1 19
20 (% style="width:753.446px" %)
21 |**Process**|(% style="width:670px" %)**Description**
Helena 4.1 22 |1|(% style="width:670px" %)Retrieve the [[DSD>>doc:sdmx:Glossary.Data structure definition.WebHome]] from a [[structural metadata>>doc:sdmx:Glossary.Structural metadata.WebHome]] source (e.g. an [[SDMX Registry>>doc:sdmx:Glossary.SDMX Registry.WebHome]]), and create database tables.
23 |2|(% style="width:670px" %)Read an [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] [[data set>>doc:sdmx:Glossary.Data set.WebHome]] file and load the data into the database
24 |3|(% style="width:670px" %)Data discovery system continually synchronises its metadata with the [[structural metadata>>doc:sdmx:Glossary.Structural metadata.WebHome]] source. A user makes a data selection from choices built from the information held in an [[SDMX Registry>>doc:sdmx:Glossary.SDMX Registry.WebHome]] ([[structural metadata>>doc:sdmx:Glossary.Structural metadata.WebHome]] such as [[category scheme>>doc:sdmx:Glossary.Category scheme.WebHome]], [[dataflow>>doc:sdmx:Glossary.Dataflow.WebHome]], [[DSD>>doc:sdmx:Glossary.Data structure definition.WebHome]], [[data provider>>doc:sdmx:Glossary.Data provider.WebHome]], [[provision agreements>>doc:sdmx:Glossary.Provision agreement.WebHome]] and data registration)
25 |3|(% style="width:670px" %)These choices are logical choices, built from the [[dimension>>doc:sdmx:Glossary.Dimension.WebHome]] selections.
26 |5|(% style="width:670px" %)The logical choice is formatted as an [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] data query. This is passed to the Data Base which responds with an [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] [[data set>>doc:sdmx:Glossary.Data set.WebHome]].
27 |6|(% style="width:670px" %)[[Reference metadata>>doc:sdmx:Glossary.Reference metadata.WebHome]] relevant to the data returned is retrieved from a [[metadata repository>>doc:sdmx:Glossary.Metadata repository.WebHome]].
28 |7|(% style="width:670px" %)The data and metadata are passed to a visualization tool to display the data in tables, charts, graphs, (% style="color:#e74c3c" %)maps(%%) etc. Often a download is offered in various formats. The download options often include also the [[DSD>>doc:sdmx:Glossary.Data structure definition.WebHome]] or MSD.
Artur 1.1 29
30 == 16.3 Structural Metadata ==
31
32 === 16.3.1 Schematic ===
33
Helena 4.1 34 The following [[structural metadata>>doc:sdmx:Glossary.Structural metadata.WebHome]] and provisioning metadata is used in the scenario.
Artur 1.1 35
36 [[image:image-20250318221512-2.jpeg||data-xwiki-image-style-alignment="center"]]
37
38 (% style="text-align: center;" %)
39 **{{id name="image_48"/}}Figure 48: Structural and Provisioning Metadata Used in the Scenario**
40
41 === 16.3.2 Data Structure Definition ===
42
Helena 4.1 43 For the reasons of clarity a sub set of the contents of the [[Code Lists>>doc:sdmx:Glossary.Code list.WebHome]] and [[Concept Schemes>>doc:sdmx:Glossary.Concept scheme.WebHome]] are used in this example, and only a few of the [[DSD>>doc:sdmx:Glossary.Data structure definition.WebHome]] [[Attributes>>doc:sdmx:Glossary.Attribute.WebHome]] are used.
Artur 1.1 44
Helena 2.1 45 (% class="wikigeneratedid" id="HDimensions" %)
46 **Dimensions**
Artur 1.1 47
48 (% style="text-align: center;" %)
49 [[image:image-20250318221512-3.jpeg]]** **
50
Helena 2.1 51 (% class="wikigeneratedid" id="HAttributes" %)
52 **Attributes**
Artur 1.1 53
54 (% style="text-align: center;" %)
55 [[image:image-20250318221512-4.jpeg]]** **
56
Helena 2.1 57 (% class="wikigeneratedid" id="HGroup" %)
58 **Group**
Artur 1.1 59
60 (% style="text-align: center;" %)
61 [[image:image-20250318221512-5.jpeg]]** **
62
Helena 2.1 63 (% class="wikigeneratedid" id="HPrimaryMeasure" %)
64 **Primary Measure**
Artur 1.1 65
66 (% style="text-align: center;" %)
67 [[image:image-20250318221512-6.jpeg]]** **
68
69 == 16.4 Scenario Steps ==
70
71 === 16.4.1 Create Data Base ===
72
73 [[image:image-20250318221512-7.jpeg||data-xwiki-image-style-alignment="center"]]
74
75 (% style="text-align: center;" %)
76 **{{id name="image_49"/}}Figure 49: User Case - Create Database Tables from DSD**
77
Helena 6.1 78 The following [[SDMX-ML>>doc:sdmx:Glossary.SDMX-ML.WebHome]] is extracted from the Registry using the REST query
79 http:~/~/[ ws-entry-point]/DataStructure_ECB/ECB_EXR1
Artur 1.1 80
Helena 3.1 81 (% class="wikigeneratedid" id="HDimensions" %)
82 **Dimensions**
Artur 1.1 83
84 [[image:image-20250318221512-8.jpeg||data-xwiki-image-style-alignment="center"]]
85
86 Note that for brevity only the XML of the FREQ and TIME_PERIOD are shown in full.
87
Helena 2.1 88 (% class="wikigeneratedid" id="HNotes" %)
89 **Notes**
Artur 1.1 90
Helena 4.2 91 1. A [[Dimension>>doc:sdmx:Glossary.Dimension.WebHome]] can state its position in the key, but the actual sequence is defined by the sequence in the i.e. the inferred sequence in the  takes precedence over the value of the position attribute.
Helena 4.3 92 1. This [[DSD>>doc:sdmx:Glossary.Data structure definition.WebHome]] is converted from (% style="color:#e74c3c" %)version(%%) 2.0. The (% style="color:#e74c3c" %)version(%%) 2.0 (% style="color:#e74c3c" %)Concepts(%%) were standalone in the form  <Concept agencyID=”ECB” version=”1.0”/>
Helena 4.2 93 1. The standalone (% style="color:#e74c3c" %)concept(%%) is not supported in 2.1 and any standalone (% style="color:#e74c3c" %)concept(%%) is placed in a [[Concept Scheme>>doc:sdmx:Glossary.Concept scheme.WebHome]] with the Id “STANDALONE_CONCEPT_SCHEME” of the (% style="color:#e74c3c" %)version(%%) corresponding to the (% style="color:#e74c3c" %)version(%%) of the original standalone (% style="color:#e74c3c" %)concept(%%).
Artur 1.1 94
Helena 2.1 95 (% class="wikigeneratedid" id="HGroup-1" %)
96 **Group**
Artur 1.1 97
98 (% style="text-align: center;" %)
99 [[image:image-20250318221512-9.jpeg]]** **
100
101 **Notes:**
102
Helena 5.1 103 1. A Group in (% style="color:#e74c3c" %)version(%%) 2.1 plays the same role as it does in (% style="color:#e74c3c" %)version(%%) 2.0 except that it does not group Series in the [[data set>>doc:sdmx:Glossary.Data set.WebHome]]. The Group in (% style="color:#e74c3c" %)version(%%) 2.1 is used solely as a mechanism to attach [[Attributes>>doc:sdmx:Glossary.Attribute.WebHome]] in the [[data set>>doc:sdmx:Glossary.Data set.WebHome]].
104 1. The Group in (% style="color:#e74c3c" %)version(%%) 2.1 is retained for compatibility with (% style="color:#e74c3c" %)version(%%) 2.0 and for avoiding repetition in the new [[Attribute Relationship>>doc:sdmx:Glossary.Attribute relationship.WebHome]] construct which is introduced in (% style="color:#e74c3c" %)version(%%) 2.1.
Artur 1.1 105
Helena 3.1 106 (% class="wikigeneratedid" id="HAttributes" %)
107 **Attributes**
Artur 1.1 108
109 [[image:image-20250318221512-10.jpeg||data-xwiki-image-style-alignment="center"]]
110
111 [[image:image-20250318221512-11.jpeg||data-xwiki-image-style-alignment="center"]]
112
Helena 5.1 113 Note that for brevity only the XML of the [[DECIMALS>>doc:sdmx:Glossary.Decimals.WebHome]] (relationship to a group) COLLECTION (relationship to a set of [[Dimensions>>doc:sdmx:Glossary.Dimension.WebHome]]) and OBS_CONF (relationship to the Primary [[Measure>>doc:sdmx:Glossary.Measure.WebHome]]) are shown in full.
Artur 1.1 114
Helena 2.1 115 (% class="wikigeneratedid" id="HNotes-1" %)
116 **Notes**
Artur 1.1 117
Helena 5.1 118 1. The [[Attribute>>doc:sdmx:Glossary.Attribute.WebHome]] has a relationship to either a [[data set>>doc:sdmx:Glossary.Data set.WebHome]] of one or more [[Dimensions>>doc:sdmx:Glossary.Dimension.WebHome]] as described in Chapter 4.
119 1. [[DECIMALS>>doc:sdmx:Glossary.Decimals.WebHome]] has a relationship to a Group with the Id of Group.
120 1. COLLECTION has a relationship to a set of [[Dimensions>>doc:sdmx:Glossary.Dimension.WebHome]] – in this case this is, in reality, the [[series key>>doc:sdmx:Glossary.Series key.WebHome]] as this has been converted from (% style="color:#e74c3c" %)version(%%) 2.0. It is possible for an [[attribute>>doc:sdmx:Glossary.Attribute.WebHome]] to have a relationship with just one, a few, or all of the [[Dimensions>>doc:sdmx:Glossary.Dimension.WebHome]].
121 1. OBS_CONF has a relationship with the Primary [[Measure>>doc:sdmx:Glossary.Measure.WebHome]].
Artur 1.1 122
Helena 2.1 123 (% class="wikigeneratedid" id="HMeasure" %)
124 **Measure**
Artur 1.1 125
126 [[image:image-20250318221512-12.jpeg||data-xwiki-image-style-alignment="center"]]
127
Helena 5.1 128 A typical database schema that can be set up using this [[DSD>>doc:sdmx:Glossary.Data structure definition.WebHome]] is shown below.
Artur 1.1 129
Helena 2.1 130 (% class="wikigeneratedid" id="HSeriesKeyTable" %)
131 **Series Key Table**
Artur 1.1 132
133 [[image:image-20250318221902-34.png||data-xwiki-image-style-alignment="center"]]
134
135 (% style="text-align: center;" %)
136 **{{id name="image_50"/}}Figure 50: Relational Table Structure created from a DSD Dimensions and Related Attributes**
137
Helena 2.1 138 (% class="wikigeneratedid" id="HGroup201CGroup201DTable" %)
139 **Group “Group” Table**
Artur 1.1 140
141 (% style="text-align: center;" %)
142 [[image:image-20250318221512-13.jpeg]]** **
143
144 (% style="text-align: center;" %)
145 **{{id name="image_51"/}}Figure 51: Relational Table Structure created from a DSD Group and Related Attributes**
146
Helena 2.1 147 (% class="wikigeneratedid" id="HObservation" %)
148 **Observation**
Artur 1.1 149
150 [[image:image-20250318221512-14.jpeg||data-xwiki-image-style-alignment="center"]]
151
152 (% style="text-align: center;" %)
153 **{{id name="image_52"/}}Figure 52: Relational Table Structure created from a DSD Primary Measure and Related Attributes**
154
155 === 16.4.2 Load Database ===
156
157 [[image:image-20250318221512-15.jpeg||data-xwiki-image-style-alignment="center"]]
158
159 (% style="text-align: center;" %)
160 **{{id name="image_53"/}}Figure 53: Loading an SDMX Dataset into a Database **
161
Helena 5.1 162 The following is an extract from the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] [[dataset>>doc:sdmx:Glossary.Data set.WebHome]].
Artur 1.1 163
164 [[image:image-20250319123255-1.png||data-xwiki-image-style-alignment="center"]]
165
166 [[image:image-20250319123339-2.png||data-xwiki-image-style-alignment="center"]]
167
168 Note that this is a sub set of the actual data message.
169
Helena 2.1 170 (% class="wikigeneratedid" id="HNotes-2" %)
171 **Notes**
Artur 1.1 172
Helena 5.1 173 1. The reference to the [[DSD>>doc:sdmx:Glossary.Data structure definition.WebHome]] is given in the message header and given a local structureId
174 1. The local structureId ([[DSD>>doc:sdmx:Glossary.Data structure definition.WebHome]]) is referenced from the [[DataSet>>doc:sdmx:Glossary.Data set.WebHome]]
175 1. A Group does not contain Series in (% style="color:#e74c3c" %)version(%%) 2.1: it is used solely to declare attributes
176 1. The first in the first has an OBS_VALUE of “NaN”. This is an XML expression that declared a value of “not a number”, thus allowing a “missing value” to be declared.
177 1. A [[dataset>>doc:sdmx:Glossary.Data set.WebHome]] can contain observations from different frequencies.
Artur 1.1 178
179 The diagrams below show the database content based on the schema created.
180
Helena 2.1 181 (% class="wikigeneratedid" id="HSeriesKeyTable-1" %)
182 **Series Key Table**
Artur 1.1 183
184 [[image:image-20250318221512-16.jpeg||data-xwiki-image-style-alignment="center"]]
185
Helena 2.1 186 (% class="wikigeneratedid" id="HGroupTable" %)
187 **Group Table**
Artur 1.1 188
189 [[image:image-20250318221512-17.jpeg||data-xwiki-image-style-alignment="center"]]
190
Helena 2.1 191 (% class="wikigeneratedid" id="HObservationTable" %)
192 **Observation Table**
Artur 1.1 193
194 (% style="text-align: center;" %)
195 [[image:image-20250318221512-18.jpeg]]** **
196
197 The database is now available for query.
198
199 === 16.4.3 Register Data Source ===
200
201 The following registration is submitted to the Registry.
202
203 [[image:image-20250318221512-19.jpeg||data-xwiki-image-style-alignment="center"]]
204
Helena 5.1 205 The [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] web service of the database can now be searched for in the Registry.
Artur 1.1 206
207 === 16.4.4 Retrieve and Visualise Category Scheme and Dataflows ===
208
209 [[image:image-20250318221512-20.jpeg||data-xwiki-image-style-alignment="center"]]
210
211 (% style="text-align: center;" %)
212 **{{id name="image_54"/}}Figure 54: Building a Search Screen from Structural Metadata**
213
Helena 5.1 214 The following REST query will return the [[Category Scheme>>doc:sdmx:Glossary.Category scheme.WebHome]] and Categorisations that reference any of the [[Categories>>doc:sdmx:Glossary.Category.WebHome]] in the scheme.
Artur 1.1 215
216 [[http:~~/~~/ ~[ws-entry-point~]/categoryscheme/ECB/SDW_ECONOMIC_CONCEPTS/1.0?references=parents>>http:// [ws-entry-point]/categoryscheme/ECB/SDW_ECONOMIC_CONCEPTS/1.0?references=parents||rel="noopener noreferrer" target="_blank"]]
217
218 [[image:image-20250318221512-21.jpeg||data-xwiki-image-style-alignment="center"]]
219
220 [[image:image-20250318221512-22.jpeg||data-xwiki-image-style-alignment="center"]]
221
Helena 5.1 222 The application will now retrieve the [[Dataflows>>doc:sdmx:Glossary.Dataflow.WebHome]] in the list of Categorisations – in this case there is only one – effective exchange rates.
Artur 1.1 223
Helena 5.1 224 The following REST query will return the [[dataflow>>doc:sdmx:Glossary.Dataflow.WebHome]].
Artur 1.1 225
Artur 9.1 226 [[http:~~/~~/ ~[ws-entry-point~]/dataflow/ECB/2034482/1.0>>http://[ws-entry-point]/dataflow/ECB/2034482/1.0||rel="noopener noreferrer" target="_blank"]]
Artur 1.1 227
228 [[image:image-20250318221512-23.jpeg||data-xwiki-image-style-alignment="center"]]
229
230 The actual choreography of the query application is dependent upon the implementation but the following is assumed for this example.
231
232 1. Query application queries the Registry for the Provision Agreement.
233 1. Query application queries the Registry for data Registrations.
Helena 5.1 234 1. If there is a [[data source>>doc:sdmx:Glossary.Data source.WebHome]] registered then the [[dataflow>>doc:sdmx:Glossary.Dataflow.WebHome]] is displayed and can be selected.
Artur 1.1 235
Helena 5.1 236 The following REST query will return any [[provision agreements>>doc:sdmx:Glossary.Provision agreement.WebHome]] referenced from the [[dataflow>>doc:sdmx:Glossary.Dataflow.WebHome]]
Artur 1.1 237
238 [[http:~~/~~/~[ws-entry-point~]/dataflow/ECB/2034482/1.0?references=provisionagreement>>http://[ws-entry-point]/dataflow/ECB/2034482/1.0?references=provisionagreement||rel="noopener noreferrer" target="_blank"]]
239
240 [[image:image-20250318221512-24.jpeg||data-xwiki-image-style-alignment="center"]]
241
Helena 2.1 242 (% class="wikigeneratedid" id="HNotes-3" %)
243 **Notes**
Artur 1.1 244
Helena 5.1 245 ~1. The contains the same identification information as the individual [[attributes>>doc:sdmx:Glossary.Attribute.WebHome]] in the tag in the context of the <Dataflow> and tags (the <Dataflow> identifies that the is a DataStructure).
Artur 1.1 246
Helena 5.1 247 The following REST query will return the [[Data Provider Scheme>>doc:sdmx:Glossary.Data provider scheme.WebHome]] that contains the [[Data Provider>>doc:sdmx:Glossary.Data provider.WebHome]] connected to the [[Provision Agreement>>doc:sdmx:Glossary.Provision agreement.WebHome]]. Note that this is not necessary in order to query for the data unless the [[Data Provider>>doc:sdmx:Glossary.Data provider.WebHome]] contains information required by the query application (such as the name of the [[Data Provider>>doc:sdmx:Glossary.Data provider.WebHome]]).
Artur 1.1 248
Artur 10.1 249 [[http:~~/~~/~[ws-entry-point~]/dataprovider/ECB>>http:// [ws-entry-point]/dataprovider/ECB||rel="noopener noreferrer" target="_blank"]]
Artur 1.1 250
Helena 2.1 251 (% class="wikigeneratedid" id="HNotes-4" %)
252 **Notes**
Artur 1.1 253
Helena 5.1 254 1.
Artur 1.1 255
Helena 5.1 256 As an Agency can have only one [[Data Provider Scheme>>doc:sdmx:Glossary.Data provider scheme.WebHome]] and this has a mandatory Id of DATA_PROVIDER_SCHEME and must be (% style="color:#e74c3c" %)version(%%) 1.0 there is no need to specify any other parameters to the REST query.
Artur 1.1 257
Helena 5.1 258 This returns the following as part of the [[Data Provider Scheme>>doc:sdmx:Glossary.Data provider scheme.WebHome]].
259
Artur 1.1 260 [[image:image-20250318221512-25.jpeg||data-xwiki-image-style-alignment="center"]]
261
Helena 5.1 262 The following Registry query will return the REST [[data source>>doc:sdmx:Glossary.Data source.WebHome]] referenced in a Registration for the Provision Agreement
Artur 1.1 263
264 [[image:image-20250318221512-26.jpeg||data-xwiki-image-style-alignment="center"]]
265
266 The response from this query is:
267
268 [[image:image-20250318221512-27.jpeg||data-xwiki-image-style-alignment="center"]]
269
270 The query application now has the details of the web service to call when making a query, and it also knows that the query expected uses the REST interface.
271
272 [[http:~~/~~/~[ws-entry-point~] /~[RESTParameters~]>>http://[ws-entry-point] /[RESTParameters||rel="noopener noreferrer" target="_blank"]]]
273
Helena 5.1 274 Where [ws-entry-point] is the URL of the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] web service and [RESTParameters] are the query parameters.
Artur 1.1 275
276 The application can now visualize the information it has retrieved from the Registry in a way that is meaningful to the user. An example visualization is shown below.
277
278 [[image:image-20250318221512-28.jpeg||data-xwiki-image-style-alignment="center"]]
279
280 (% style="text-align: center;" %)
281 **{{id name="image_55"/}}Figure 55: Example Query Screen Built from SDMX Category Scheme and Dataflows**
282
Helena 5.1 283 The user will select the [[Category>>doc:sdmx:Glossary.Category.WebHome]] and this then shows the [[Dataflows>>doc:sdmx:Glossary.Dataflow.WebHome]] that are available and which have data available for query (i.e. there is a Registration). There can be many such [[Dataflows>>doc:sdmx:Glossary.Dataflow.WebHome]] but in this example there is only one.
Artur 1.1 284
285 === 16.4.5 Build Dimension Selection and Logical Query ===
286
287 [[image:image-20250318221512-29.jpeg||data-xwiki-image-style-alignment="center"]]
288
Helena 5.1 289 Clicking on the [[Dataflow>>doc:sdmx:Glossary.Dataflow.WebHome]] will cause the query application to query the Registry for the [[DSD>>doc:sdmx:Glossary.Data structure definition.WebHome]] associated to the [[Dataflow>>doc:sdmx:Glossary.Dataflow.WebHome]]. The [[Dimensions>>doc:sdmx:Glossary.Dimension.WebHome]] and the relevant [[codes>>doc:sdmx:Glossary.Code.WebHome]] associated with the [[Dimensions>>doc:sdmx:Glossary.Dimension.WebHome]] are then shown for detailed data selections.
Artur 1.1 290
291 [[image:image-20250318221512-30.jpeg||data-xwiki-image-style-alignment="center"]]
292
293 (% style="text-align: center;" %)
294 **{{id name="image_56"/}}Figure 56: Selection Screen build from SDMX DSD**
295
Helena 5.1 296 The user can click on each of the [[Dimensions>>doc:sdmx:Glossary.Dimension.WebHome]] and the relevant [[code>>doc:sdmx:Glossary.Code.WebHome]] selections are displayed. Note that in the example above the application is assumed to have queries for all the keys so that it can process them in order to grey-out the [[Dimension>>doc:sdmx:Glossary.Dimension.WebHome]] selections for which there is no data. These are greyed-out based on the current selections in the other [[Dimensions>>doc:sdmx:Glossary.Dimension.WebHome]]. This shows the importance of content (% style="color:#e74c3c" %)constraints(%%) in a web dissemination system, as they can be used to guide the user to make only the selections that will return data. The same result can be achieved if these (% style="color:#e74c3c" %)constraints(%%) are available for query (e.g. in a Registry), but this is a less effective way of processing if the contenrts of the database are dynamic.
Artur 1.1 297
298 === 16.4.6 Query Database ===
299
300 [[image:image-20250318221512-31.jpeg||data-xwiki-image-style-alignment="center"]]
301
Helena 5.1 302 The logical query of the user is converted to an [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] query and sent to the Data Web Service of the data publisher. The Data Web Service may also query the [[Metadata Repository>>doc:sdmx:Glossary.Metadata repository.WebHome]] in order to return both data and related metadata to the user application. The Data Web Service may also require [[structural metadata>>doc:sdmx:Glossary.Structural metadata.WebHome]] ([[DSD>>doc:sdmx:Glossary.Data structure definition.WebHome]] and [[MSD>>doc:sdmx:Glossary.Metadata structure definition.WebHome]] and related [[Code Lists>>doc:sdmx:Glossary.Code list.WebHome]] and (% style="color:#e74c3c" %)Concepts(%%)) from the [[structural metadata>>doc:sdmx:Glossary.Structural metadata.WebHome]] repository, in this example this an [[SDMX Registry>>doc:sdmx:Glossary.SDMX Registry.WebHome]].
Artur 1.1 303
Helena 2.1 304 (% class="wikigeneratedid" id="HDataQueryLogicalSelections" %)
305 **Data Query Logical Selections**
Artur 1.1 306
307 (% style="width:551.446px" %)
308 |(% style="width:261px" %)**Dimension**|(% style="width:286px" %)**Values**
309 |(% style="width:261px" %)FREQ|(% style="width:286px" %)M
310 |(% style="width:261px" %)CURRENCY|(% style="width:286px" %)Z26,Z28
311 |(% style="width:261px" %)CURRENCY_DENOM|(% style="width:286px" %)EUR,CZK,DKK
312 |(% style="width:261px" %)EXR-TYPE|(% style="width:286px" %)DFCO,EN00
313 |(% style="width:261px" %)EXR_SUFFIX|(% style="width:286px" %)A
314 |(% style="width:261px" %)Time|(% style="width:286px" %)Jan 2008-Dec 2010
315
Helena 2.1 316 (% class="wikigeneratedid" id="HRESTQuery" %)
317 **REST Query**
Artur 1.1 318
319 [[http:~~/~~/ws-entry-point/data/2034482/M.Z26+Z28.EUR+CZK+DKK.DFC0+EN00+A /ECB?startPeriod=2008-01&endPeriod=2010-12&detail=dataonly>>http://ws-entry-point/data/2034482/M.Z26+Z28.EUR+CZK+DKK.DFC0+EN00+A /ECB?startPeriod=2008-01&endPeriod=2010-12&detail=dataonly||rel="noopener noreferrer" target="_blank"]]
320
321 === 16.4.7 Visualise the Resultant Data Set ===
322
323 [[image:image-20250318221512-32.jpeg||data-xwiki-image-style-alignment="center" height="310" width="346"]]
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Helena 5.1 325 The returned data and metadata can be presented to the user in many ways – tables, graphs, charts, (% style="color:#e74c3c" %)maps(%%) etc. [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] does not support visualization directly but it is possible to define roles for a [[Dimension>>doc:sdmx:Glossary.Dimension.WebHome]] and [[Attribute>>doc:sdmx:Glossary.Attribute.WebHome]] in the [[DSD>>doc:sdmx:Glossary.Data structure definition.WebHome]]. For instance, it is possible to assign a role of “Geography” or “[[Title>>doc:sdmx:Glossary.Title.WebHome]]” or “[[Measure>>doc:sdmx:Glossary.Measure.WebHome]] Unit” etc. which will aid a data visualization service to present this information in a meaningful way to the user.
Artur 1.1 326
327 [[image:image-20250318221512-33.jpeg||data-xwiki-image-style-alignment="center"]]
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329 (% style="text-align: center;" %)
330 **{{id name="image_57"/}}Figure 57: Example Graph Built from Data Returned from a Query**