Index0utOfBoundsException occurs when execute merge statement without sharding generated key

[strongduanmu]

Bug Report

Which version of ShardingSphere did you use?

b7294f7

Which project did you use? ShardingSphere-JDBC or ShardingSphere-Proxy?

ShardingSphere-Proxy

Expected behavior

Execute merge statement successfully when I not config sharding generated key.

Actual behavior

Reason analyze (If you can)

The generated in ShardingSphereColumn should indicate whether to use the distributed key, rather than the id generated in the underlying db. This logic is correct in earlier versions (such as 5.0.0).

shardingsphere/shardingsphere-features/shardingsphere-sharding/shardingsphere-sharding-core/src/main/java/org/apache/shardingsphere/sharding/metadata/ShardingTableMetaDataBuilder.java

Line 122 in d3409a2

boolean generated = entry.getKey().equalsIgnoreCase(tableRule.getGenerateKeyColumn().orElse(null));

The logic of the latest version is wrong. It will first determine whether it is a distributed ID. If not, it will use the ID generated in the db.

Steps to reproduce the behavior, such as: SQL to execute, sharding rule configuration, when exception occur etc.

Example codes for reproduce this issue (such as a github link).