Using Java to Implement Couchbase Aggregated Queries

Couchbase is a high-performance distributed NoSQL database that provides powerful aggregation query capabilities. In Java, Couchbase's Java SDK can be used to implement various aggregation queries. Firstly, ensure that you have added the coordinates of the Couchbase Java SDK to the Maven dependencies of the project: <dependency> <groupId>com.couchbase.client</groupId> <artifactId>java-client</artifactId> <version>3.1.4</version> </dependency> Next, you can follow the following steps to implement various data aggregation queries: 1. Import the required classes: import com.couchbase.client.java.Cluster; import com.couchbase.client.java.ClusterOptions; import com.couchbase.client.java.json.JsonArray; import com.couchbase.client.java.json.JsonObject; import com.couchbase.client.java.query.QueryOptions; import com.couchbase.client.java.query.QueryResult; 2. Create a Couchbase cluster connection: String connectionString = "couchbase://localhost"; String username = "your-username"; String password = "your-password"; Cluster cluster = Cluster.connect(connectionString, ClusterOptions .clusterOptions(username, password)); 3. Execute aggregation query: Suppose we have a bucket called "employees", which contains a JSON field with the key "name" and a JSON field with the key "age". We will implement various aggregation queries using the following examples. -Count String statementCount = "SELECT COUNT(*) AS count FROM `employees`"; QueryResult resultCount = cluster.query(statementCount); JsonObject rowCount = resultCount.rowsAsObject().get(0); long count = rowCount.getLong("count"); -Sum String statementSum = "SELECT SUM(age) AS sum FROM `employees`"; QueryResult resultSum = cluster.query(statementSum); JsonObject rowSum = resultSum.rowsAsObject().get(0); long sum = rowSum.getLong("sum"); -Avg String statementAvg = "SELECT AVG(age) AS avg FROM `employees`"; QueryResult resultAvg = cluster.query(statementAvg); JsonObject rowAvg = resultAvg.rowsAsObject().get(0); double avg = rowAvg.getDouble("avg"); -Maximum value (max) String statementMax = "SELECT MAX(age) AS max FROM `employees`"; QueryResult resultMax = cluster.query(statementMax); JsonObject rowMax = resultMax.rowsAsObject().get(0); int max = rowMax.getInt("max"); -Minimum value (min) String statementMin = "SELECT MIN(age) AS min FROM `employees`"; QueryResult resultMin = cluster.query(statementMin); JsonObject rowMin = resultMin.rowsAsObject().get(0); int min = rowMin.getInt("min"); 4. Close connection: cluster.disconnect(); The above are the basic steps and sample code for implementing various aggregation queries in Couchbase using Java. You can modify the query statements and JSON result processing according to specific needs.