edmiRemoteSelectInstanceReferences
EdmiError edmiRemoteSelectInstanceReferences(SdaiServerContext serverContextId, SdaiInstance currInst, SdaiVersion version, SdaiString condition, SdaiOptions options, SdaiString attributes, SdaiVoid include_exclude_filter, SdaiString orderBy, SdaiInteger *index, SdaiInteger *numberOfHits, SdaiQueryResult *queryResult, SdaiString xmlConfigurationName, SdaiString *resultString, SdaiString resultFileName, SdaiInvocationId *edmiInvocationId);
Search in the specified remote edmModel with a given server context for instances that externally reference a given instance and that that match a given condition. The condition may be any legal symbolic Express-X logical expression. A NULL or empty string condition will match all the instances that refer to the given instance. For each application instance in the edmModel the system automatically maintains a reference aggregate containing the instanceIds of all the instances that externally refers to it. Hence, these externally referring instances, which of course may be of any instance type, will allways be available in the instances reference aggregate. It is this reference aggregate that will be searched for instances that match the given condition. Note that if the edmModel was created with the option NO_INSTANCE_REFERENCES, no reference aggregate will be maintained. The advantage of this is that data manipulation performance improves for the edmModel. On the other hand, the drawback is that this function will not work. The index of the first reference aggregate element to check, and the maximum number of matching instances to return, are specified as input arguments to the function. The actual number of matching instances returned and the "index of the last returned matching instance in the reference aggregate" will be returned from the function. This makes it possible to query through huge amounts of instances by means of a loop where each iteration handles a small subset of the total reference aggregate. See the example below. The <condition> argument will be compiled by the EDMexpressXCompiler. The specified query will be executed by the EDMexpressVM. The <attributes> argument may contain a "dot expression" including Express built-in functions and EDMexpressX xpf built-in functions.
Attributes argument syntax example: "Name sizeof(sdai_model.underlying_schema.entities)"
This example is from an edmiRemoteSelectInstances operation on the EDM_MODEL objects in the SystemRepository.ExpressDataManager model. There will be 2 columns
- The Name attribute of the EDM_MODEL
- The number of entities in the "underlying schema" of the model.
The column names in the resulting "query table" will be "name" and "sizeof(sdai_model.underlying_schema.entities)" respectively. By using the "->" characters, a new column name can be specified. Example: if we want the 2nd column to be given the name "entities", we may write the 2nd attribute like this: "sizeof(sdai_model.underlying_schema.entities)->Entities"
Note that the characters white space, comma, and semicolon are all used as delimiters between the attribute "names" in the attributes argument, hence none of these characters can be used in the attribute name/attribute expression. The remote edmModel to query must be open before this operation can be successfully performed. The total number of hits will be returned in the <numberOfHits> argument.
Arguments
1 | Type | Name | Comment |
2 | SdaiServerContext | serverContextId | Context identification, from edmiDefineServerContext |
3 | SdaiInstance | currInst | The instance Id that uniquely identifies the application instance in the remote EDMdatabasefor which the given condition shall be checked for all its external references. |
4 | SdaiVersion | version | The version number of the edmModel to run the query on. The version number is a sequense number counting from one by increments of one. Use version 0 for current version. |
5 | SdaiString | condition | The condition that the instances in the reference aggregate shall match. A NULL or empty string condition will match all the instances in the aggregate. A valid condition is any Express-X logical expression that refers to any number of attributes defined for the reference instance type. Because the reference aggregate may contain instances of any type, the situation where the condition referees to attributes that are not defined for that particular instance type may occur. In this case, the logical expression will evaluate to xpxUNKNOWN. Hence, that instance will not be considered matching the condition. |
6 | SdaiOptions | options | See description of available options below. Options may be joined by using bitwise OR operator |
7 | SdaiString | attributes | Specification of the title and contents of each column of the returned query result table. The following examples illustrate the syntax. |
8 | SdaiVoid | include_exclude_filter | A zero-terminated buffer of entityIds or a NULL-terminated buffer of string pointers to entity names.
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9 | SdaiString | orderBy | Name of the query result column to use for sorting. The column may be specified by its constructor or by the column title. |
10 | SdaiInteger | index |
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11 | SdaiInteger | numberOfHits |
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12 | SdaiQueryResult | queryResult | A variable that will receive the result of the query. Use edmiFreeQueryResult to release allocated memory. |
13 | SdaiString | xmlConfigurationName | The name of the XML configuration to apply to the resulting XML formatted query result when the option XML_FORMAT is used. |
14 | SdaiString | resultString | Variable that will receive the returned XML, HTML or ASCII formatted query result when the option RESULT_IN_STRING is used with one of the options HTML_FORMAT, ASCII_FORMAT or XML_FORMAT. |
15 | SdaiString | resultFileName | The name of the file that will contain the returned XML, HTML or ASCII formatted query result. Only applicable when using the RESULT_IN_FILE option in combination with one of the options HTML_FORMAT, ASCII_FORMAT or XML_FORMAT. |
16 | SdaiInvocationId | edmiInvocationId | Currently not used. |
Return Value
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Options
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1 | Option | Comment |
2 | ALL_ATTRIBUTES | When the argument <attributes> is NULL or an empty string, all attributes of the instances will be included in the query result. However, if the <attributes> argument is used to add one or more additional constructed columns or to rename a column in the query result, the return of all the instance attributes will be hindered due to an <attributes> argument that is no longer NULL or an empty string. Use this option to force the including of all instance attributes even when the <attributes> argument is not NULL or an empty string. |
3 | INCLUDE_CONFIGURATION | Includes the XML Configuration in the generated ISO10303-28 compliant XML formatted query result. This option has no effect unless combined with the option XML_FORMAT. |
4 | INCLUDE_SCHEMA | Includes the underlying meta data in the generated ISO10303-28 compliant XML formatted query result. This option has no effect unless combined with the option XML_FORMAT. |
5 | RESULT_IN_STRING | The resulting table will be returned in a string allocated in heap-memory of the calling application. Use the option RESULT_IN_FILE to write the table to a file. |
6 | EXTRACT_SHALLOW | Use this option to force a shallow XML formatted query result. ISO10303-28 compliant XML Query results are deep by default. No other query result format supported by this function is deep. Hence, this option has no effect unless combined with the option XML_FORMAT. |
7 | TRANSFER_NO_DATA | No query result will be returned from the remote EDMdatabase. Use this option when the number of matching instances is the only information needed or for testing the query syntax before actually performing it. |
8 | ASCENDING | Arrange the query result instances in ascending order. This option is only applicable when the <orderBy> argument is used. |
9 | DESCENDING | Arrange the query result instances in descending order. This option is only applicable when the <orderBy> argument is used. |
10 | ONLY_INSTANCE_IDS | Return only a single column with the instanceIds of the matching instances. |
11 | INCLUDE_INSTANCE_IDS | Prepend all attribute columns in the query result with an instanceId column. |
12 | INCLUDE_FILTER | Only instances of the entities listed in the <include_exclude_filter> argument will be queried. |
13 | EXCLUDE_FILTER | All instances except those of the entities listed in the <include_exclude_filter> argument will be queried |
14 | RESULT_IN_FILE | The resulting table will be written to a file on the local file system of the calling application. The name of the file must be specified in the <resultFileName> argument. |
15 | EDM_IDENTIFIERS | The instanceIds that uniquely identify the instances in the remote EDMdatabase will be used as xmlIds for identification of the instances within the ISO10303-28 compliant XML formatted query result. |
16 | FILTER_AS_ENTITY_NAMES | The <include_exclude_filter> argument will be interpreted as a NULL-terminated buffer of string pointers. Each string pointer must give the name of an entity to include into or exclude from the query. |
17 | FILTER_AS_ENTITY_IDS | The <include_exclude_filter> argument will be interpreted as a zero-terminated buffer of entityIds. Each entityId must identify an entity to include into or exclude from the query. |
18 | HTML_FORMAT | The query result table will be presented in HTML format in a locally allocated string or in a file on the local file system. See the options RESULT_IN_FILE and RESULT_IN_STRING. |
19 | ASCII_FORMAT | The query result table will be presented in plain ASCII format in a locally allocated string or in a file on the local file system. See the options RESULT_IN_FILE and RESULT_IN_STRING. |
20 | OLD_XML_FORMAT | The result of the query will be returned in a simple well formed XML formatted file on the local file system. |
21 | XML_FORMAT | The result of the query will be returned in an ISO10303-28 compliant XML formatted string or in a file on the local file system. |
22 | ZIPPED_FILE | The file given by the argument <resultFileName> will be compressed . This option has no effect unless combined with the option RESULT_IN_FILE. |
23 | IGNORE_EMPTY_COLUMNS | Columns for attributes that do not have defined values for any of the returned instances will be left out of the query result table. |
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Example
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#define S_BATCHSIZE 10 EdmiError rstat; SdaiServerContext myContext; SdaiInteger index, nHits, nTot; SdaiQueryResult qexRes; char condition[1024], *pCond; char attrs[1024], *pAttrs; SdaiOptions options; SdaiInstance johnnysId; /* Create Server Context */ rstat = edmiDefineServerContext("MyContext", "Johnny", "Supervisor", "cf37ftr", "TCP", "9090", "MyServerHost", NULL, NULL, NULL, NULL, NULL, &myContext); /* Get Johnnys instance Id */ nHits = S_BATCHSIZE; index = 0; options = ONLY_INSTANCE_IDS | SUBTYPES; pCond = &condition[0]; pCond += sprintf(pCond, "(LAST_NAME = 'Jackson')"); pCond += sprintf(pCond, " AND (FIRST_NAME = 'Johnny')"); pCond += sprintf(pCond, " AND (BIRTH_DATE = '19631216)')"); rstat = edmiRemoteSelectInstances(myContext, "DataRepository", "SocialRelations", "Person", condition, options, NULL, NULL, NULL, &index, &nHits, &qexRes, NULL, NULL, NULL, NULL); if (nHits != 1) { printf("\n%s", nHits ? "Ambigious" : "Not found"); if (nHits) edmiFreeQueryResult(qexRes); goto err; } johnnysId = qexRes->instanceIds[0]; edmiFreeQueryResult(qexRes); /* Are there any females older than 16 years that refere to Johnny as their boyfriend */ pCond = &condition[0]; pCond += sprintf(pCond, "(BOYFRIEND :=: johnnysId)"); pCond += sprintf(pCond, " AND (AGE >= 16)"); options = TRANSFER_NO_DATA; index = 0; nHits = 1; /* One is enough. */ rstat = edmiRemoteSelectInstanceReferences(myContext, 0, johnnysId, condition, options, NULL, NULL, NULL, &index, &nHits, &qexRes, NULL, NULL, NULL, NULL); if (nHits) { /* Read them in batches of 10. Note that index now already points at johnnys first potential girlfriend */ nTot = 0; nHits = S_BATCHSIZE; options = RESULT_IN_STRING | ASCENDING; pAttrs = &attrs[0]; pAttrs += sprintf(pAttrs, "LAST_NAME->FamilyName"); pAttrs += sprintf(pAttrs, ";FIRST_NAME->Name"); pAttrs += sprintf(pAttrs, ";AGE->Age"); pAttrs += sprintf(pAttrs, ";PHONE_NO->Phone"); while (nHits = S_BATCHSIZE) { SdaiString _resString; rstat = edmiRemoteSelectInstanceReferences(myContext, 0, johnnysId, condition, options, attrs, NULL, "AGE", &index, &nHits, &qexRes, NULL, &_resString, NULL, NULL); printf("\n\n%s", _resString); edmiFree(_resString); nTot += nHits; ++index; } printf("\n\n%d potential girlfriends found", nTot); } else { printf("\nSorry Johnny, no potential girlfriends found."); } . . .
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