I have a database that acts like a triple store, except that it is just a simple MySQL database.
I want to select all triples that have a common predicate and object. Info about RDF and triples
I can't seem to work out the SQL.
If I had just a single predicate and object to match I would do:
select TRIPLE from TRIPLES where PREDICATE="predicateName" and OBJECT="objectName"
But if I have a list (HashMap) of many pairs of (predicateName,objectName) I am not sure what I need to do.
Please let me know if I need to provide more info, I am not sure that I have made this quite clear, but I am wary of providing too much info and confusing the issue.
可能将您的哈希图加载到临时表中,然后对三元组存储进行JOIN
。
select TRIPLE from TRIPLES where PREDICATE in (?,?,?,........) and OBJECT in (?,?,?,?,.....)
Populate the `?'s using HashMap.keys and HashMap.values. Depending on language and data-access method, use either bound parameters (ODBC and other methods) or expand the parameters building up the sql yourself.
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