NoSuchElementException when execute DALStatement without USE DB #34224
Description
Bug Report
Which version of ShardingSphere did you use?
5.5.2-SNAPSHOT a6a09ba
Which project did you use? ShardingSphere-JDBC or ShardingSphere-Proxy?
ShardingSphere-Proxy
Expected behavior
Query from unicast database
Actual behavior
Steps to reproduce the behavior, such as: SQL to execute, sharding rule configuration, when exception occur etc.
- Create logical database and register storage unit;
- Quit current session;
- Connect to Proxy and do not execute
USE DB; - Execute SQL
show variables where Variable_name in ('explicit_defaults_for_timestamp', 'sql_mode');- Proxy log
java.util.NoSuchElementException: null
at java.base/java.util.Collections$EmptyIterator.next(Collections.java:4310)
at org.apache.shardingsphere.infra.session.query.QueryContext.getUsedDatabase(QueryContext.java:95)
at org.apache.shardingsphere.proxy.backend.connector.StandardDatabaseConnector.<init>(StandardDatabaseConnector.java:126)
at org.apache.shardingsphere.proxy.backend.connector.DatabaseConnectorFactory.newInstance(DatabaseConnectorFactory.java:52)
at org.apache.shardingsphere.proxy.backend.handler.data.impl.UnicastDatabaseBackendHandler.execute(UnicastDatabaseBackendHandler.java:62)
at org.apache.shardingsphere.proxy.frontend.mysql.command.query.text.query.MySQLComQueryPacketExecutor.execute(MySQLComQueryPacketExecutor.java:93)
at org.apache.shardingsphere.proxy.frontend.command.CommandExecutorTask.doExecuteCommand(CommandExecutorTask.java:126)
at org.apache.shardingsphere.proxy.frontend.command.CommandExecutorTask.executeCommand(CommandExecutorTask.java:121)
at org.apache.shardingsphere.proxy.frontend.command.CommandExecutorTask.run(CommandExecutorTask.java:78)
at com.alibaba.ttl.TtlRunnable.run(TtlRunnable.java:60)
at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1136)
at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:635)
at java.base/java.lang.Thread.run(Thread.java:840)