[GitHub] [shardingsphere] lmhmhl commented on issue #8883: Create unit test for `CalciteJDBCExecutor` to test SQL federation feature

[GitBox]

lmhmhl commented on issue #8883:
URL: https://github.com/apache/shardingsphere/issues/8883#issuecomment-758753986


   Hi @tristaZero,
   Thanks for your sincere advice, I tried again followed by your  
instructions. Firstly, I prepare a `ShardingSphereDataSource`  with 
CALCITE_DB_NAMES which is a single database instance,  then configure the yaml 
file named `config-calcite.yaml` and add tables rules as follow, this is a 
single table without sharding rules. Next, I Inserts a piece of data into the 
database，then prepare a SQL["SELECT id, cipher_pwd, plain_pwd FROM t_encrypt 
WHERE id = ?";] to retrieve the data inserted just now. After that, when I 
execute the test, some unexpected error happen again. In `executeQuery()`, a 
method of `ShardingSpherePreparedStatement`, `queryResults` is returned by 
`executeQuery0()` which execute query by Calcite, and return value is not null 
showing that Calcite do query successfully, the weird thing is that when 
creating `ShardingSphereResultSet`, it needs to invoke 
`statement.getResultSet()` and the return value is null, thus 
`resultSets.get(0).getMetaData()` in `ShardingSphereResu
 ltSet` method would cast NullPointerException. 
   The `queryResults` and `mergedResult ` are both not null in executeQuery(), 
but `this::getResultSet` returns null, I don't know what went wrong about my 
method, can u give me some hints, THX.
   
   
   ```
   rules:
     - !SHARDING
       tables:
         t_encrypt:
           actualDataNodes: jdbc_0.t_encrypt
   ```
   ```
    public ResultSet executeQuery() throws SQLException {
           ResultSet result;
           try {
               clearPrevious();
               executionContext = createExecutionContext();
               List<QueryResult> queryResults = executeQuery0();
               MergedResult mergedResult = mergeQuery(queryResults);
               result = new 
ShardingSphereResultSet(statements.stream().map(this::getResultSet).collect(Collectors.toList()),
 mergedResult, this, executionContext);
           } finally {
               clearBatch();
           }
           currentResultSet = result;
           return result;
       }
   ```
   ```
   public ShardingSphereResultSet(final List<ResultSet> resultSets, final 
MergedResult mergeResultSet, final Statement statement, final ExecutionContext 
executionContext) throws SQLException {
           super(resultSets, statement, executionContext);
           this.mergeResultSet = mergeResultSet;
           columnLabelAndIndexMap = 
createColumnLabelAndIndexMap(resultSets.get(0).getMetaData());
       }
   ```
   <img width="1342" alt="Screen Shot 2021-01-12 at 8 38 47 PM" 
src="https://user-images.githubusercontent.com/24718258/104338435-77681380-5531-11eb-80bd-db3b558930c1.png";>
   <img width="886" alt="Screen Shot 2021-01-12 at 8 38 13 PM" 
src="https://user-images.githubusercontent.com/24718258/104338469-8222a880-5531-11eb-8141-d6eacf22afd5.png";>
   <img width="1289" alt="Screen Shot 2021-01-12 at 8 37 28 PM" 
src="https://user-images.githubusercontent.com/24718258/104338500-8cdd3d80-5531-11eb-8720-29850a70c1bb.png";>
   
   The ExecutionContext is as follows:
   <img width="1264" alt="Screen Shot 2021-01-12 at 10 04 30 PM" 
src="https://user-images.githubusercontent.com/24718258/104338816-dfb6f500-5531-11eb-8024-18998946067b.png";>
   


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