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  1. Teiid
  2. TEIID-5783

OUTER JOIN yields wrong results when used with GROUP BY, CASE and COUNT DISTINCT

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    • Resolution: Done
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    • 12.3, 12.1.2, 12.2.2
    • 12.0
    • Query Engine
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      1. Add file resource adapter in standalone-teiid.xml:

                      <resource-adapter id="file">
                    <module slot="main" id="org.jboss.teiid.resource-adapter.file"/>
                    <connection-definitions>
                        <connection-definition class-name="org.teiid.resource.adapter.file.FileManagedConnectionFactory" jndi-name="java:/files" enabled="true" pool-name="files">
                            <config-property name="AllowParentPaths">
                                true
                            </config-property>
                            <config-property name="ParentDirectory">
                                C:/testdata
                            </config-property>
                        </connection-definition>
                    </connection-definitions>
                </resource-adapter>

      2. Add MySQL database configuration in standalone-teiid.xml:

                      <datasource jndi-name="java:/test_dwh_my" pool-name="test_dwh_my" enabled="true" use-java-context="true">
                    <connection-url>jdbc:mysql://localhost:3306/dwh?zeroDateTimeBehavior=convertToNull</connection-url>
                    <driver>mysql</driver>
                    <new-connection-sql>set SESSION sql_mode = 'ANSI'</new-connection-sql>
                    <pool>
                        <min-pool-size>2</min-pool-size>
                        <max-pool-size>70</max-pool-size>
                    </pool>
                    <security>
                        <user-name>root</user-name>
                        <password>XXXXXX</password>
                    </security>
                    <validation>
                        <valid-connection-checker class-name="org.jboss.jca.adapters.jdbc.extensions.mysql.MySQLValidConnectionChecker"/>
                        <exception-sorter class-name="org.jboss.jca.adapters.jdbc.extensions.mysql.MySQLExceptionSorter"/>
                    </validation>
                    <timeout>
                        <blocking-timeout-millis>120000</blocking-timeout-millis>
                        <idle-timeout-minutes>5</idle-timeout-minutes>
                    </timeout>
                </datasource>

      3. Add in test-vdb.xml java:/test_dwh_my configured in previous step as datasource:

          <model name="dwh_my">
        <property name="importer.useFullSchemaName" value="false"/>
        <property name="importer.tableTypes" value="TABLE,VIEW"/>
        <property name="importer.importKeys" value="false"/>
        <source name="test_dwh_my" translator-name="mylobs" connection-jndi-name="java:/test_dwh_my"/>
    </model>

    <translator name="mylobs" type="mysql5">
        <property name="CopyLobs" value="true" />
        <property name="SupportsNativeQueries" value="true"/>
    </translator>

      4. Configure in the test-vdb.xml the following virtual view:

          <model visible = "true" type = "VIRTUAL" name = "views">
        <metadata type = "DDL"><![CDATA[
          create view vLeft as
SELECT
"csv_table"."created_at",
"csv_table"."order_id",
"csv_table"."store_id" 
FROM
(call files.getFiles('test1.csv')) f,
	TEXTTABLE(to_chars(f.file,'UTF-8') 
		COLUMNS 
		"created_at" STRING ,
		"order_id" STRING ,
		"store_id" STRING 
		DELIMITER ';' 
		QUOTE '"' 
		HEADER 1 
	)
"csv_table"
        ]]>
        </metadata>
    </model>

      5. Load the data from the other file (test2.csv - attached to this issue) into a MySQL table or a MS SQL table (vRight table name in my case, all fields have varchar types).

      6. Run the statement below (rebuy_check column contains no NULLs, that's correct):

      select 
count( a."order_id") anzahl_orders, 
(case when b."order_id" is not null then 'Direct Rebuy' else 'Standard' end) rebuy_check
FROM views.vLeft a
left JOIN dwh_my.vRight b on b.order_id=a.order_id
group by
(case when b."order_id" is not null then 'Direct Rebuy' else 'Standard' end) ;;

      7. Add a DISTINCT to the COUNT (rebuy_check column now contains NULLs, that's incorrect):

      select 
count(distinct a."order_id") anzahl_orders, 
(case when b."order_id" is not null then 'Direct Rebuy' else 'Standard' end) rebuy_check
FROM views.vLeft a
left JOIN dwh_my.vRight b on b.order_id=a.order_id
group by
(case when b."order_id" is not null then 'Direct Rebuy' else 'Standard' end) ;;

      8. Remove the COUNT entirely (rebuy_check column now contains NULLs, that's incorrect):

      select 
(case when b."order_id" is not null then 'Direct Rebuy' else 'Standard' end) rebuy_check
FROM views.vLeft a
left JOIN dwh_my.vRight b on b.order_id=a.order_id
group by
(case when b."order_id" is not null then 'Direct Rebuy' else 'Standard' end) ;;
      Show
      1. Add file resource adapter in standalone-teiid.xml: <resource-adapter id= "file" > <module slot= "main" id= "org.jboss.teiid.resource-adapter.file" /> <connection-definitions> <connection-definition class-name= "org.teiid.resource.adapter.file.FileManagedConnectionFactory" jndi-name= "java:/files" enabled= "true" pool-name= "files" > <config-property name= "AllowParentPaths" > true </config-property> <config-property name= "ParentDirectory" > C:/testdata </config-property> </connection-definition> </connection-definitions> </resource-adapter> 2. Add MySQL database configuration in standalone-teiid.xml: <datasource jndi-name= "java:/test_dwh_my" pool-name= "test_dwh_my" enabled= "true" use-java-context= "true" > <connection-url> jdbc:mysql://localhost:3306/dwh?zeroDateTimeBehavior=convertToNull </connection-url> <driver> mysql </driver> <new-connection-sql> set SESSION sql_mode = 'ANSI' </new-connection-sql> <pool> <min-pool-size> 2 </min-pool-size> <max-pool-size> 70 </max-pool-size> </pool> <security> <user-name> root </user-name> <password> XXXXXX </password> </security> <validation> <valid-connection-checker class-name= "org.jboss.jca.adapters.jdbc.extensions.mysql.MySQLValidConnectionChecker" /> <exception-sorter class-name= "org.jboss.jca.adapters.jdbc.extensions.mysql.MySQLExceptionSorter" /> </validation> <timeout> <blocking-timeout-millis> 120000 </blocking-timeout-millis> <idle-timeout-minutes> 5 </idle-timeout-minutes> </timeout> </datasource> 3. Add in test-vdb.xml java:/test_dwh_my configured in previous step as datasource: <model name= "dwh_my" > <property name= "importer.useFullSchemaName" value= "false" /> <property name= "importer.tableTypes" value= "TABLE,VIEW" /> <property name= "importer.importKeys" value= "false" /> <source name= "test_dwh_my" translator-name= "mylobs" connection-jndi-name= "java:/test_dwh_my" /> </model> <translator name= "mylobs" type= "mysql5" > <property name= "CopyLobs" value= "true" /> <property name= "SupportsNativeQueries" value= "true" /> </translator> 4. Configure in the test-vdb.xml the following virtual view: <model visible = "true" type = "VIRTUAL" name = "views" > <metadata type = "DDL" > <![CDATA[ create view vLeft as SELECT "csv_table" . "created_at" , "csv_table" . "order_id" , "csv_table" . "store_id" FROM (call files.getFiles( 'test1.csv' )) f, TEXTTABLE(to_chars(f.file, 'UTF-8' ) COLUMNS "created_at" STRING , "order_id" STRING , "store_id" STRING DELIMITER ';' QUOTE '"' HEADER 1 ) "csv_table" ]]> </metadata> </model> 5. Load the data from the other file (test2.csv - attached to this issue) into a MySQL table or a MS SQL table (vRight table name in my case, all fields have varchar types). 6. Run the statement below (rebuy_check column contains no NULLs, that's correct): select count ( a . "order_id" ) anzahl_orders, ( case when b. "order_id" is not null then 'Direct Rebuy' else 'Standard' end ) rebuy_check FROM views.vLeft a left JOIN dwh_my.vRight b on b.order_id= a .order_id group by ( case when b. "order_id" is not null then 'Direct Rebuy' else 'Standard' end ) ;; 7. Add a DISTINCT to the COUNT (rebuy_check column now contains NULLs, that's incorrect): select count ( distinct a . "order_id" ) anzahl_orders, ( case when b. "order_id" is not null then 'Direct Rebuy' else 'Standard' end ) rebuy_check FROM views.vLeft a left JOIN dwh_my.vRight b on b.order_id= a .order_id group by ( case when b. "order_id" is not null then 'Direct Rebuy' else 'Standard' end ) ;; 8. Remove the COUNT entirely (rebuy_check column now contains NULLs, that's incorrect): select ( case when b. "order_id" is not null then 'Direct Rebuy' else 'Standard' end ) rebuy_check FROM views.vLeft a left JOIN dwh_my.vRight b on b.order_id= a .order_id group by ( case when b. "order_id" is not null then 'Direct Rebuy' else 'Standard' end ) ;;

      Some queries that involve an OUTER JOIN between objects from different data sources, a GROUP BY with a CASE statement and a COUNT DISTINCT yield inconsistent results on a SELECT expression which is identical to the GROUP BY expression with CASE.

      • Reproduced in combination of <File> LEFT JOIN <MySQL> and <File> LEFT JOIN <MS SQL> and the same for the other OUTER JOIN variants.
      • screenshot for the different queries are attached
      • sample data for reproduction is attached

      The same problem happens with LEFT OUTER JOIN, RIGHT OUTER JOIN and FULL OUTER JOIN.

        1. test1.csv
          13 kB
        2. test2.csv
          4 kB

              rhn-engineering-shawkins Steven Hawkins
              dalex005 Dmitrii Pogorelov
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                Created:
                Updated:
                Resolved: