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dxvargas
Asked: 2024-06-25 01:42:18 +0800 CST

Virtuoso 37000 错误 SP031：SPARQL 编译器：常量子句中不允许使用变量

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这是我尝试用“创建”日期填充空白的“发布于”日期的结果。

Virtuoso 37000 Error SP031: SPARQL compiler: Variable 'entity' is not allowed in a constant clause

SPARQL query:
define sql:big-data-const 0
#output-format:text/html
define sql:signal-void-variables 1

INSERT DATA {
  GRAPH <http://mysite.eu/collection/published> {
    ?entity <http://mysite.eu/collection/published-at> ?created
    WHERE {
      SELECT ?entity ?created WHERE {
        GRAPH <http://mysite.eu/collection/published> {
          {
            ?entity <http://purl.org/dc/terms/issued> ?created .
            OPTIONAL { ?s <http://mysite.eu/collection/published-at> ?published . }
            FILTER(!bound(?published))
          }
        }
      }
    }
  }
}

这里出了什么问题？ 提到的常量子句是什么意思？ 如何修复它？

编辑1：

我使用更简单的查询也会出现类似的错误，如下所示：

Virtuoso 37000 Error SP031: SPARQL compiler: Variable 'o' is not allowed in a constant clause

SPARQL query:
define sql:big-data-const 0
#output-format:text/html
define sql:signal-void-variables 1

DELETE DATA {
  GRAPH <http://mysite.eu/collection/published> {
    <http://data.europa.eu/w21/33598e9e-2654-4639-9528-d70772837ce4> <http://mysite.eu/collection/published-at> ?o
  }
}

编辑 2：DELETE 查询工作正常，如下所示：

DELETE WHERE {
  GRAPH <http://mysite.eu/collection/published> {
    <http://data.europa.eu/w21/33598e9e-2654-4639-9528-d70772837ce4> <http://mysite.eu/collection/published-at> ?o
  }
}
sparql

1 个回答

  1. Best Answer

    此 SPARQL 更新查询无效。此INSERT DATA操作不允许变量WHERE等FILTER。您需要使用INSERT包含子句的操作WHERE：

    INSERT {
  # you can refer to the variables from the WHERE clause here
}

WHERE {
  # you can create variables here
}

    您的WHERE子句本身也存在问题：?entity包含所有具有dcterms:issued值的实例。包含所有没有值的?s实例（而不仅仅是 中的实例） 。因此，您可能希望使用 变量而不是。?entity:published-at?entity?s

    类似这样的方法可能对你有用：

    PREFIX dcterms: <http://purl.org/dc/terms/>
PREFIX : <http://mysite.eu/collection/>

WITH <http://mysite.eu/collection/published> 
# only use WITH to query and write to the same graph
# if you don’t want that, you can include 'GRAPH' patterns in the 'INSERT' and in the 'WHERE' instead

INSERT {
  ?entity :published-at ?created .
}

WHERE {
  ?entity dcterms:issued ?created .
  FILTER NOT EXISTS { ?entity :published-at [] . }
}
    • 2

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