feat: support filter after aggregation (#105)

Author: thunderz99

README.md

@@ -23,7 +23,7 @@ java-cosmos is a client for Azure CosmosDB 's SQL API (also called documentdb fo
 <dependency>
   <groupId>com.github.thunderz99</groupId>
     <artifactId>java-cosmos</artifactId>
-    <version>0.6.8</version>
+    <version>0.6.9</version>
 </dependency>
 ```
 
@@ -293,14 +293,19 @@ The main difference between Partial update and Patch is that:
 
 ```java
     // support aggregate function: COUNT, AVG, SUM, MAX, MIN
-    // see https://docs.microsoft.com/en-us/azure/cosmos-db/sql-query-aggregate-functions
-    var aggregate = Aggregate.function("COUNT(1) AS facetCount").groupBy("location", "gender");
+// see https://docs.microsoft.com/en-us/azure/cosmos-db/sql-query-aggregate-functions
+    var aggregate=Aggregate.function("COUNT(1) AS facetCount").groupBy("location","gender");
 
-    var result = db.aggregate("Collection1", aggregate, Condition.filter("age >=", 20));
+    var result=db.aggregate("Collection1",aggregate,Condition.filter("age >=",20));
 
     // will generate a sql like this:
     /* SELECT COUNT(1) as facetCount, c.location, c.gender WHERE age >= 20 GROUP BY c.location, c.gender
-    */
+     */
+
+    // Also supports filtering the aggregation result
+    var aggregate=Aggregate.function("COUNT(1) AS facetCount").groupBy("location","gender")
+    .conditionAfterAggregate(Condition.filter("facetCount >",1)) // filter after aggregation
+    ;
 ```
 
 ### Increment

pom.xml

@@ -4,7 +4,7 @@
     <groupId>com.github.thunderz99</groupId>
     <artifactId>java-cosmos</artifactId>
     <packaging>jar</packaging>
-    <version>0.6.8</version>
+    <version>0.6.9</version>
     <name>${project.groupId}:${project.artifactId}$</name>
     <description>A lightweight Azure CosmosDB client for Java</description>
     <url>https://github.com/thunderz99/java-cosmos</url>

src/main/java/io/github/thunderz99/cosmos/CosmosDatabase.java

@@ -877,7 +877,9 @@ CosmosDocumentList find(String coll, Aggregate aggregate, Condition cond, String
             queryRequestOptions.setPartitionKey(new com.azure.cosmos.models.PartitionKey(partition));
         }
 
-        var querySpec = cond.toQuerySpec(aggregate);
+        var querySpec = aggregate == null ?
+                cond.toQuerySpec() : // normal query
+                cond.toQuerySpecForAggregate(aggregate); // aggregate query//
 
         var container = this.clientV4.getDatabase(db).getContainer(coll);
 

src/main/java/io/github/thunderz99/cosmos/condition/Aggregate.java

@@ -9,45 +9,62 @@
  */
 public class Aggregate {
 
-	/**
-	 * Default constructor
-	 */
-	public Aggregate() {
-	}
-
-	public String function = "";
-
-	public Set<String> groupBy = new LinkedHashSet<>();
-
-	/**
-	 * set function
-	 *
-	 * <p>
-	 *     aggregate functions like: COUNT, AVG, SUM, MAX, MIN <br>
-	 *     see <a href="https://docs.microsoft.com/en-us/azure/cosmos-db/sql-query-aggregate-functions">cosmosdb aggregate functions</a>
-	 * </p>
-	 *
-	 *
-	 * @param function aggregate functions like:
-	 * @return Aggregate
-	 */
-	public static Aggregate function(String function) {
-		
-		Aggregate ret = new Aggregate();
-		ret.function = function;
-
-		return ret;
-	}
-
-
-	public Aggregate groupBy(String... fields) {
-
-		if (fields == null || fields.length == 0) {
-			return this;
-		}
-
-		this.groupBy = new LinkedHashSet<>(List.of(fields));
-		return this;
-	}
+    /**
+     * Default constructor
+     */
+    public Aggregate() {
+    }
+
+    public String function = "";
+
+    public Set<String> groupBy = new LinkedHashSet<>();
+
+
+    /**
+     * condition for the result of aggregation
+     */
+    public Condition condAfterAggregate = null;
+
+    /**
+     * set function
+     *
+     * <p>
+     * aggregate functions like: COUNT, AVG, SUM, MAX, MIN <br>
+     * see <a href="https://docs.microsoft.com/en-us/azure/cosmos-db/sql-query-aggregate-functions">cosmosdb aggregate functions</a>
+     * </p>
+     *
+     * @param function aggregate functions like:
+     * @return Aggregate
+     */
+    public static Aggregate function(String function) {
+
+        Aggregate ret = new Aggregate();
+        ret.function = function;
+
+        return ret;
+    }
+
+
+    public Aggregate groupBy(String... fields) {
+
+        if (fields == null || fields.length == 0) {
+            return this;
+        }
+
+        this.groupBy = new LinkedHashSet<>(List.of(fields));
+        return this;
+    }
+
+    /**
+     * Add filter / sort / limit that applies to the result of aggregation
+     *
+     * @param condAfterAggregate
+     * @return aggregate obj self
+     */
+    public Aggregate conditionAfterAggregate(Condition condAfterAggregate) {
+        this.condAfterAggregate = condAfterAggregate;
+        return this;
+    }
+
 
 }