【发布时间】：2017-08-07 17:04:56
【问题描述】：
我正在尝试使用以下语法在 Apache Ignite 上创建视图：
emplCache.query(new SqlFieldsQuery(
"CREATE VIEW EmployeeCopy AS (SELECT * FROM Employee);")).getAll();
（假设表 Employee 可用并且其中有数据）。 当这条线被执行时，我得到以下异常：
javax.cache.CacheException: class org.apache.ignite.IgniteCheckedException: null
at org.apache.ignite.internal.processors.query.GridQueryProcessor.querySqlFields(GridQueryProcessor.java:1823)
at org.apache.ignite.internal.processors.cache.IgniteCacheProxy.query(IgniteCacheProxy.java:795)
at org.apache.ignite.internal.processors.cache.IgniteCacheProxy.query(IgniteCacheProxy.java:765)
at com.demo.ignite.test1.EmployeeQuery2.createCopyTable(EmployeeQuery2.java:71)
at com.demo.ignite.test1.EmployeeQuery2.main(EmployeeQuery2.java:55)
Caused by: class org.apache.ignite.IgniteCheckedException: null
at org.apache.ignite.internal.processors.query.GridQueryProcessor.executeQuery(GridQueryProcessor.java:2316)
at org.apache.ignite.internal.processors.query.GridQueryProcessor.querySqlFields(GridQueryProcessor.java:1820)
... 4 more
Caused by: java.lang.NullPointerException
at org.apache.ignite.internal.processors.query.h2.IgniteH2Indexing.queryDistributedSqlFields(IgniteH2Indexing.java:1343)
at org.apache.ignite.internal.processors.query.GridQueryProcessor$5.applyx(GridQueryProcessor.java:1815)
at org.apache.ignite.internal.processors.query.GridQueryProcessor$5.applyx(GridQueryProcessor.java:1813)
at org.apache.ignite.internal.util.lang.IgniteOutClosureX.apply(IgniteOutClosureX.java:36)
at org.apache.ignite.internal.processors.query.GridQueryProcessor.executeQuery(GridQueryProcessor.java:2293)
... 5 more
我在 IgniteH2Indexing.java 类的第 1343 行看到变量“twoStepQry”为空。如果我错过了什么，我无法理解。
我正在使用 apache-ignite-2.1.0。
另外，如果我创建一个 VIEW，它在内部是如何工作的？它是锁定缓存中的那些条目，还是将其复制到其他缓存？
【问题讨论】：
标签： ignite