[
https://issues.apache.org/jira/browse/GORA-497?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16104521#comment-16104521
]
ASF GitHub Bot commented on GORA-497:
-------------------------------------
Github user djkevincr commented on a diff in the pull request:
https://github.com/apache/gora/pull/110#discussion_r130021447
--- Diff:
gora-cassandra-cql/src/main/java/org/apache/gora/cassandra/serializers/CassandraQueryFactory.java
---
@@ -0,0 +1,701 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.gora.cassandra.serializers;
+
+import com.datastax.driver.core.querybuilder.Delete;
+import com.datastax.driver.core.querybuilder.QueryBuilder;
+import com.datastax.driver.core.querybuilder.Select;
+import com.datastax.driver.core.querybuilder.Update;
+import org.apache.gora.cassandra.bean.CassandraKey;
+import org.apache.gora.cassandra.bean.ClusterKeyField;
+import org.apache.gora.cassandra.bean.Field;
+import org.apache.gora.cassandra.bean.KeySpace;
+import org.apache.gora.cassandra.bean.PartitionKeyField;
+import org.apache.gora.cassandra.query.CassandraQuery;
+import org.apache.gora.cassandra.store.CassandraMapping;
+import org.apache.gora.query.Query;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+import java.util.Locale;
+import java.util.Map;
+
+/**
+ * This class is used create Cassandra Queries.
+ */
+class CassandraQueryFactory {
+
+ private static final Logger LOG =
LoggerFactory.getLogger(CassandraQueryFactory.class);
+
+ /**
+ * This method returns the CQL query to create key space.
+ * refer :
http://docs.datastax.com/en/cql/3.1/cql/cql_reference/create_keyspace_r.html
+ *
+ * @param mapping Cassandra Mapping {@link CassandraMapping}
+ * @return CQL Query
+ */
+ static String getCreateKeySpaceQuery(CassandraMapping mapping) {
+ KeySpace keySpace = mapping.getKeySpace();
+ StringBuilder stringBuffer = new StringBuilder();
+ stringBuffer.append("CREATE KEYSPACE IF NOT EXISTS
").append(keySpace.getName()).append(" WITH REPLICATION = { 'class' : ");
+ KeySpace.PlacementStrategy placementStrategy =
keySpace.getPlacementStrategy();
+
stringBuffer.append("'").append(placementStrategy).append("'").append(",
").append("'");
+ switch (placementStrategy) {
+ case SimpleStrategy:
+ stringBuffer.append("replication_factor").append("'").append(" :
").append(keySpace.getReplicationFactor()).append(" }");
+ break;
+ case NetworkTopologyStrategy:
+ boolean isCommaNeeded = false;
+ for (Map.Entry<String, Integer> entry :
keySpace.getDataCenters().entrySet()) {
+ if (isCommaNeeded) {
+ stringBuffer.append(", '");
+ }
+ stringBuffer.append(entry.getKey()).append("'").append(" :
").append(entry.getValue());
+ isCommaNeeded = true;
+ }
+ stringBuffer.append(" }");
+ break;
+ }
+
+ if (keySpace.isDurableWritesEnabled()) {
+ stringBuffer.append(" AND DURABLE_WRITES =
").append(keySpace.isDurableWritesEnabled());
+ }
+ return stringBuffer.toString();
+ }
+
+ /**
+ * This method returns the CQL query to table.
+ * refer :
http://docs.datastax.com/en/cql/3.1/cql/cql_reference/create_table_r.html
+ * <p>
+ * Trick : To have a consistency of the order of the columns, first we
append partition keys, second cluster keys and finally other columns.
+ * It's very much needed to follow the same order in other CRUD
operations as well.
+ *
+ * @param mapping Cassandra mapping {@link CassandraMapping}
+ * @return CQL Query
+ */
+ static String getCreateTableQuery(CassandraMapping mapping) {
+ StringBuilder stringBuffer = new StringBuilder();
+ stringBuffer.append("CREATE TABLE IF NOT EXISTS
").append(mapping.getKeySpace().getName()).append(".").append(mapping.getCoreName()).append("
(");
+ boolean isCommaNeeded = false;
+ CassandraKey cassandraKey = mapping.getCassandraKey();
+ // appending Cassandra key columns into db schema
+ for (Field field : mapping.getFieldList()) {
+ if (isCommaNeeded) {
+ stringBuffer.append(", ");
+ }
+ stringBuffer.append(field.getColumnName()).append("
").append(field.getType());
+ boolean isStaticColumn =
Boolean.parseBoolean(field.getProperty("static"));
+ boolean isPrimaryKey =
Boolean.parseBoolean(field.getProperty("primarykey"));
+ if (isStaticColumn) {
+ stringBuffer.append(" STATIC");
+ }
+ if (isPrimaryKey) {
+ stringBuffer.append(" PRIMARY KEY ");
+ }
+ isCommaNeeded = true;
+ }
+
+ if (cassandraKey != null) {
+ List<PartitionKeyField> pkey = cassandraKey.getPartitionKeyFields();
+ if (pkey != null) {
+ stringBuffer.append(", PRIMARY KEY (");
+ boolean isCommaNeededToApply = false;
+ for (PartitionKeyField keyField : pkey) {
+ if (isCommaNeededToApply) {
+ stringBuffer.append(",");
+ }
+ if (keyField.isComposite()) {
+ stringBuffer.append("(");
+ boolean isCommaNeededHere = false;
+ for (Field field : keyField.getFields()) {
+ if (isCommaNeededHere) {
+ stringBuffer.append(", ");
+ }
+ stringBuffer.append(field.getColumnName());
+ isCommaNeededHere = true;
+ }
+ stringBuffer.append(")");
+ } else {
+ stringBuffer.append(keyField.getColumnName());
+ }
+ isCommaNeededToApply = true;
+ }
+ stringBuffer.append(")");
+ }
+ } else {
+ if
(!stringBuffer.toString().toLowerCase(Locale.ENGLISH).contains("primary key")) {
+ Field field = mapping.getDefaultCassandraKey();
+ stringBuffer.append(", ").append(field.getFieldName()).append("
").append(field.getType()).append(" PRIMARY KEY ");
+ }
+ }
+
+ stringBuffer.append(")");
+ boolean isWithNeeded = true;
+ if (Boolean.parseBoolean(mapping.getProperty("compactStorage"))) {
+ stringBuffer.append(" WITH COMPACT STORAGE ");
+ isWithNeeded = false;
+ }
+
+ String id = mapping.getProperty("id");
+ if (id != null) {
+ if (isWithNeeded) {
+ stringBuffer.append(" WITH ");
+ } else {
+ stringBuffer.append(" AND ");
+ }
+ stringBuffer.append("ID = '").append(id).append("'");
+ isWithNeeded = false;
+ }
+ if (cassandraKey != null) {
+ List<ClusterKeyField> clusterKeyFields =
cassandraKey.getClusterKeyFields();
+ if (clusterKeyFields != null) {
+ if (isWithNeeded) {
+ stringBuffer.append(" WITH ");
+ } else {
+ stringBuffer.append(" AND ");
+ }
+ stringBuffer.append(" CLUSTERING ORDER BY (");
+ boolean isCommaNeededToApply = false;
+ for (ClusterKeyField keyField : clusterKeyFields) {
+ if (isCommaNeededToApply) {
+ stringBuffer.append(", ");
+ }
+ stringBuffer.append(keyField.getColumnName()).append(" ");
+ if (keyField.getOrder() != null) {
+ stringBuffer.append(keyField.getOrder());
+ }
+ isCommaNeededToApply = true;
+ }
+ stringBuffer.append(")");
+ }
+ }
+ return stringBuffer.toString();
+ }
+
+ /**
+ * This method returns the CQL query to drop table.
+ * refer :
http://docs.datastax.com/en/cql/3.1/cql/cql_reference/drop_table_r.html
+ *
+ * @param mapping Cassandra Mapping {@link CassandraMapping}
+ * @return CQL query
+ */
+ static String getDropTableQuery(CassandraMapping mapping) {
+ return "DROP TABLE IF EXISTS " + mapping.getKeySpace().getName() + "."
+ mapping.getCoreName();
+ }
+
+ /**
+ * This method returns the CQL query to drop key space.
+ * refer :
http://docs.datastax.com/en/cql/3.1/cql/cql_reference/drop_keyspace_r.html
+ *
+ * @param mapping Cassandra Mapping {@link CassandraMapping}
+ * @return CQL query
+ */
+ static String getDropKeySpaceQuery(CassandraMapping mapping) {
+ return "DROP KEYSPACE IF EXISTS " + mapping.getKeySpace().getName();
+ }
+
+ /**
+ * This method returns the CQL query to truncate (removes all the data)
in the table.
+ * refer :
http://docs.datastax.com/en/cql/3.1/cql/cql_reference/truncate_r.html
+ *
+ * @param mapping Cassandra Mapping {@link CassandraMapping}
+ * @return CQL query
+ */
+ static String getTruncateTableQuery(CassandraMapping mapping) {
+ return "TRUNCATE TABLE " + mapping.getKeySpace().getName() + "." +
mapping.getCoreName();
+ }
+
+ /**
+ * This method return the CQL query to insert data in to the table.
+ * refer :
http://docs.datastax.com/en/cql/3.1/cql/cql_reference/insert_r.html
+ *
+ * @param mapping Cassandra Mapping {@link CassandraMapping}
+ * @param fields available fields
+ * @return CQL Query
+ */
+ static String getInsertDataQuery(CassandraMapping mapping, List<String>
fields) {
+ String[] columnNames = getColumnNames(mapping, fields);
+ String[] objects = new String[fields.size()];
+ Arrays.fill(objects, "?");
+ return QueryBuilder.insertInto(mapping.getKeySpace().getName(),
mapping.getCoreName()).values(columnNames, objects).getQueryString();
+ }
+
+ /**
+ * This method return the CQL query to delete a persistent in the table.
+ * refer :
http://docs.datastax.com/en/cql/3.3/cql/cql_reference/cqlDelete.html
+ *
+ * @param mapping Cassandra Mapping {@link CassandraMapping}
+ * @param fields filed list to be deleted
+ * @return CQL Query
+ */
+ static String getDeleteDataQuery(CassandraMapping mapping, List<String>
fields) {
+ String[] columnNames = getColumnNames(mapping, fields);
+ String[] objects = new String[fields.size()];
+ Arrays.fill(objects, "?");
+ Delete delete =
QueryBuilder.delete().from(mapping.getKeySpace().getName(),
mapping.getCoreName());
+ Delete.Where query = null;
+ boolean isWhereNeeded = true;
+ for (String columnName : columnNames) {
+ if (isWhereNeeded) {
+ query = delete.where(QueryBuilder.eq(columnName, "?"));
+ isWhereNeeded = false;
+ } else {
+ query = query.and(QueryBuilder.eq(columnName, "?"));
+ }
+ }
+ return query.getQueryString();
+ }
+
+ /**
+ * This method returns the CQL Select query to retrieve data from the
table.
+ * refer:
http://docs.datastax.com/en/cql/3.3/cql/cql_reference/cqlSelect.html
+ *
+ * @param mapping Cassandra Mapping {@link CassandraMapping}
+ * @param keyFields key fields
+ * @return CQL Query
+ */
+ static String getSelectObjectQuery(CassandraMapping mapping,
List<String> keyFields) {
+ Select select =
QueryBuilder.select().from(mapping.getKeySpace().getName(),
mapping.getCoreName());
+ if (Boolean.parseBoolean(mapping.getProperty("allowFiltering"))) {
+ select.allowFiltering();
+ }
+ String[] columnNames = getColumnNames(mapping, keyFields);
+ Select.Where query = null;
+ boolean isWhereNeeded = true;
+ for (String columnName : columnNames) {
+ if (isWhereNeeded) {
+ query = select.where(QueryBuilder.eq(columnName, "?"));
+ isWhereNeeded = false;
+ } else {
+ query = query.and(QueryBuilder.eq(columnName, "?"));
+ }
+ }
+ return query.getQueryString();
+ }
+
+ /**
+ * This method returns CQL Select query to retrieve data from the table
with given fields.
+ * This method is used for Avro Serialization
+ * refer:
http://docs.datastax.com/en/cql/3.3/cql/cql_reference/cqlSelect.html
+ *
+ * @param mapping Cassandra Mapping {@link CassandraMapping}
+ * @param fields Given fields to retrieve
+ * @param keyFields key fields
+ * @return CQL Query
+ */
+ static String getSelectObjectWithFieldsQuery(CassandraMapping mapping,
String[] fields, List<String> keyFields) {
+ Select select = QueryBuilder.select(getColumnNames(mapping,
Arrays.asList(fields))).from(mapping.getKeySpace().getName(),
mapping.getCoreName());
+ if (Boolean.parseBoolean(mapping.getProperty("allowFiltering"))) {
+ select.allowFiltering();
+ }
+ String[] columnNames = getColumnNames(mapping, keyFields);
+ Select.Where query = null;
+ boolean isWhereNeeded = true;
+ for (String columnName : columnNames) {
+ if (isWhereNeeded) {
+ query = select.where(QueryBuilder.eq(columnName, "?"));
+ isWhereNeeded = false;
+ } else {
+ query = query.and(QueryBuilder.eq(columnName, "?"));
+ }
+ }
+ return query.getQueryString();
+ }
+
+ /**
+ * This method returns CQL Select query to retrieve data from the table
with given fields.
+ * This method is used for Native Serialization
+ * refer:
http://docs.datastax.com/en/cql/3.3/cql/cql_reference/cqlSelect.html
+ *
+ * @param mapping Cassandra Mapping {@link CassandraMapping}
+ * @param fields Given fields to retrieve
+ * @return CQL Query
+ */
+ static String getSelectObjectWithFieldsQuery(CassandraMapping mapping,
String[] fields) {
+ String cqlQuery = null;
+ String[] columnNames = getColumnNames(mapping, Arrays.asList(fields));
+ Select select =
QueryBuilder.select(columnNames).from(mapping.getKeySpace().getName(),
mapping.getCoreName());
+ if (Boolean.parseBoolean(mapping.getProperty("allowFiltering"))) {
+ select.allowFiltering();
+ }
+ CassandraKey cKey = mapping.getCassandraKey();
+ if (cKey != null) {
+ Select.Where query = null;
+ boolean isWhereNeeded = true;
+ for (Field field : cKey.getFieldList()) {
+ if (isWhereNeeded) {
+ query = select.where(QueryBuilder.eq(field.getColumnName(),
"?"));
+ isWhereNeeded = false;
+ } else {
+ query = query.and(QueryBuilder.eq(field.getColumnName(), "?"));
+ }
+ }
+ cqlQuery = query != null ? query.getQueryString() : null;
+ } else {
+ for (Field field : mapping.getFieldList()) {
+ boolean isPrimaryKey =
Boolean.parseBoolean(field.getProperty("primarykey"));
+ if (isPrimaryKey) {
+ cqlQuery = select.where(QueryBuilder.eq(field.getColumnName(),
"?")).getQueryString();
+ break;
+ }
+ }
+ }
+ return cqlQuery;
+ }
+
+
+ /**
+ * This method returns CQL Query for execute method. This CQL contains a
Select Query to retrieve data from the table
+ *
+ * @param mapping Cassandra Mapping {@link CassandraMapping}
+ * @param cassandraQuery Query {@link CassandraQuery}
+ * @param objects object list
+ * @return CQL Query
+ */
+ static String getExecuteQuery(CassandraMapping mapping, Query
cassandraQuery, List<Object> objects) {
+ String[] fields = cassandraQuery.getFields();
+ fields = fields != null ? fields : mapping.getFieldNames();
+ Object startKey = cassandraQuery.getStartKey();
+ Object endKey = cassandraQuery.getEndKey();
+ Object key = cassandraQuery.getKey();
+ String primaryKey = null;
+ long limit = cassandraQuery.getLimit();
+ Select select = QueryBuilder.select(getColumnNames(mapping,
Arrays.asList(fields))).from(mapping.getKeySpace().getName(),
mapping.getCoreName());
+ if (limit > 0) {
+ select = select.limit((int) limit);
+ }
+ if (Boolean.parseBoolean(mapping.getProperty("allowFiltering"))) {
+ select.allowFiltering();
+ }
+ Select.Where query = null;
+ boolean isWhereNeeded = true;
+ if (key != null) {
+ if (mapping.getCassandraKey() != null) {
+ ArrayList<String> cassandraKeys = new ArrayList<>();
--- End diff --
For three cases key != null, startKey != null, endKey != null, I see very
similar code is duplicated across 3 cases. Please see whether we can generalize
and utility method that can be reused all three cases. Similar duplicated logic
can bee seen in methods - getExecuteQuery, getDeleteByQuery, getUpdateByQuery.
> Migrate CassandraThrift to CQL
> -------------------------------
>
> Key: GORA-497
> URL: https://issues.apache.org/jira/browse/GORA-497
> Project: Apache Gora
> Issue Type: Improvement
> Components: gora-cassandra
> Reporter: Madhawa Gunasekara
> Assignee: Madhawa Gunasekara
> Labels: gsoc2017
> Fix For: 0.8
>
>
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