chore: create azure digital twins query helper

Author: AndreaGiulianelli

src/env/infrastructure/digitaltwins/query/AdtQuery.java

@@ -0,0 +1,97 @@
+/*
+ * Copyright (c) 2023. Smart Operating Block
+ *
+ * Use of this source code is governed by an MIT-style
+ * license that can be found in the LICENSE file or at
+ * https://opensource.org/licenses/MIT.
+ */
+
+package infrastructure.digitaltwins.query;
+
+/**
+ * Helper class to construct query for Azure Digital Twins service.
+ */
+public class AdtQuery {
+    private final String query;
+
+    /**
+     * Default constructor.
+     */
+    public AdtQuery() {
+        this.query = "";
+    }
+
+    /**
+     * Private constructor used to create the query.
+     * @param query the part of the query to pre-pend.
+     */
+    private AdtQuery(final String query) {
+        this.query = query;
+    }
+
+    /**
+     * Select query considering returned elements.
+     * @param elements the elements to return from the query
+     * @return the updated query
+     */
+    public AdtQuery select(final String... elements) {
+        return new AdtQuery("SELECT " + String.join(", ", elements));
+    }
+
+    /**
+     * Select query but return only numberOfElements top elements.
+     * @param numberOfElementsToSelect the number of top elements to return
+     * @param elements the elements to return from the query
+     * @return the updated query
+     */
+    public AdtQuery selectTop(final int numberOfElementsToSelect, final String... elements) {
+        return new AdtQuery("SELECT TOP(" + numberOfElementsToSelect + ") " + String.join(", ", elements));
+    }
+
+    /**
+     * Specify the FROM digital twins clause with its alias. This alias can be used later to refer to it.
+     * @param alias the alias for the digital twin
+     * @return the updated query
+     */
+    public AdtQuery fromDigitalTwins(final String alias) {
+        return new AdtQuery(this.query + " FROM DIGITALTWINS " + alias);
+    }
+
+    /**
+     * Join the query with a relationship, specified by its relationshipName of the srcAlias digital twin.
+     * Specify also the dstAlias used to describe the destination digital twin.
+     * @param dstAlias the alias of the target of the relationship
+     * @param srcAlias the alias of the source of the relationship
+     * @param relationshipName the name of the relationship to join
+     * @return the updated query
+     */
+    public AdtQuery joinRelationship(final String dstAlias, final String srcAlias, final String relationshipName) {
+        return new AdtQuery(this.query + " JOIN " + dstAlias + " RELATED " + srcAlias + "." + relationshipName);
+    }
+
+    /**
+     * Where clause to include in the query.
+     * @param whereClause the where clause
+     * @return the updated query
+     */
+    public AdtQuery where(final String whereClause) {
+        return new AdtQuery(this.query + " WHERE " + whereClause);
+    }
+
+    /**
+     * Chain in and another where clause.
+     * @param whereClause the where clause to chain
+     * @return the updated query
+     */
+    public AdtQuery and(final String whereClause) {
+        return new AdtQuery(this.query + " AND " + whereClause);
+    }
+
+    /**
+     * Method used to export the final query.
+     * @return the query
+     */
+    public String toQuery() {
+        return this.query;
+    }
+}