Examples with SqlExprList org.apache.jena.sdb.core.sqlexpr.SqlExprList used on opensource projects

Example 1 with SqlExprList

use of org.apache.jena.sdb.core.sqlexpr.SqlExprList in project jena by apache.

the class SqlStageBasicQuad method build.

// There are three special graph names:
//   Quad.defaultGraph - the quad marker for a query pattern for the default graph.
//   Quad.defaultGraphName - the explicit internal name for the default graph
//   Quad.unionDefaultGraph - the internal name for the union of all named graphs (excluding the degault graph).
//
// If SDB.unionDefaultGraph is true in the context, then patterns on the 
// default graph are made against the union graph.
//
// If the explicit names (defaultGraphName, unionDefaultGraph) are used in GRAPH, 
// then the default or union beahviour is avilable regardless of the setting of
//  SDB.unionDefaultGraph.
@Override
public SqlNode build(SDBRequest request, SlotCompiler slotCompiler) {
    SqlExprList conditions = new SqlExprList();
    // ARQ 2.8.4 quad.isDefaultGraph() ;
    boolean defaultGraph = Quad.isDefaultGraph(quad.getGraph());
    boolean unionGraph = quad.isUnionGraph();
    // ---- Choose the mode of access.
    //quad.isDefaultGraph() ;
    boolean accessStoredDefaultGraph = Quad.isDefaultGraph(quad.getGraph());
    boolean accessUnionGraph = false;
    if (accessStoredDefaultGraph && request.getContext().isTrue(SDB.unionDefaultGraph)) {
        // Treat the default graph as the union of all triples in named graphs.
        defaultGraph = false;
        unionGraph = true;
        accessStoredDefaultGraph = false;
        accessUnionGraph = true;
    }
    // GRAPH <name of default graph> { } 
    if (quad.isDefaultGraphExplicit()) {
        // "named" access to the default graph
        accessStoredDefaultGraph = true;
        accessUnionGraph = false;
    }
    if (quad.isUnionGraph()) {
        // "named" access to the union of the named graphs
        accessStoredDefaultGraph = false;
        accessUnionGraph = true;
    // Add DISTINCT over the join of SqlStageBasicQuad for RDF merge 
    }
    // ---- Choose the table to access
    // The default graph table may be a specialized table (e.g. triples, not quads).
    TableDescQuads tableDesc = null;
    String alias = null;
    if (accessStoredDefaultGraph) {
        tableDesc = request.getStore().getTripleTableDesc();
        alias = request.genId(AliasesSql.TriplesTableBase);
    } else {
        tableDesc = request.getStore().getQuadTableDesc();
        alias = request.genId(AliasesSql.QuadTableBase);
    }
    SqlTable table = new SqlTable(alias, tableDesc.getTableName());
    if (accessStoredDefaultGraph)
        table.addNote(FmtUtils.stringForTriple(quad.asTriple(), request.getPrefixMapping()));
    else
        table.addNote(FmtUtils.stringForQuad(quad, request.getPrefixMapping()));
    if (!accessStoredDefaultGraph && !accessUnionGraph)
        slotCompiler.processSlot(request, table, conditions, quad.getGraph(), tableDesc.getGraphColName());
    slotCompiler.processSlot(request, table, conditions, quad.getSubject(), tableDesc.getSubjectColName());
    slotCompiler.processSlot(request, table, conditions, quad.getPredicate(), tableDesc.getPredicateColName());
    slotCompiler.processSlot(request, table, conditions, quad.getObject(), tableDesc.getObjectColName());
    return SqlBuilder.restrict(request, table, conditions);
}

Example 2 with SqlExprList

use of org.apache.jena.sdb.core.sqlexpr.SqlExprList in project jena by apache.

the class GenerateSQLVisitor method rewrite.

public SqlJoinInner rewrite(SqlJoinInner join) {
    if (!join.getRight().isInnerJoin())
        return join;
    // if ( join(A, join(B, C)) ) rewrite as join(join(A,B),C)
    // this then is written without brackets (and so scope changing)
    // TODO abstract as organiseJoin(List<join elements>)
    // and remember to do top down to find maximal join trees
    SqlJoinInner right = join.getRight().asInnerJoin();
    String alias1 = join.getAliasName();
    String alias2 = right.getAliasName();
    SqlNode sn_a = join.getLeft();
    SqlNode sn_b = right.getLeft();
    SqlNode sn_c = right.getRight();
    SqlExprList conditions = new SqlExprList(join.getConditions());
    conditions.addAll(right.getConditions());
    Set<SqlTable> tables_ab = sn_a.tablesInvolved();
    tables_ab.addAll(sn_b.tablesInvolved());
    // Goes to new join(A,B)
    SqlExprList newCond_ab = new SqlExprList();
    // Goes to new join(,C)
    SqlExprList newCond_c = new SqlExprList();
    // Place conditions
    for (SqlExpr e : conditions) {
        Set<SqlColumn> cols = e.getColumnsNeeded();
        // columns to tables.
        Set<SqlTable> tables = tables(cols);
        // Are the tables contained in tables_ab?
        tables.removeAll(tables_ab);
        if (tables.size() == 0)
            newCond_ab.add(e);
        else
            newCond_c.add(e);
    }
    if (newCond_ab.size() + newCond_c.size() != conditions.size())
        log.error(String.format("Conditions mismatch: (%d,%d,%d)", newCond_ab.size(), newCond_c.size(), conditions.size()));
    SqlJoinInner join2 = new SqlJoinInner(sn_a, sn_b);
    join2.addConditions(newCond_ab);
    join2 = new SqlJoinInner(join2, sn_c);
    join2.addConditions(newCond_c);
    return join2;
}