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Posted to issues@spark.apache.org by "Paul Wu (JIRA)" <ji...@apache.org> on 2016/09/20 22:13:20 UTC
[jira] [Commented] (SPARK-17614) sparkSession.read() .jdbc(***) use
the sql syntax "where 1=0" that Cassandra does not support
[ https://issues.apache.org/jira/browse/SPARK-17614?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15507950#comment-15507950 ]
Paul Wu commented on SPARK-17614:
---------------------------------
Work around: Rebuild the Cassandra JDBC wrapper by modifying CassandraPreparedStatement.java at (https://github.com/adejanovski/cassandra-jdbc-wrapper/blob/master/src/main/java/com/github/adejanovski/cassandra/jdbc/CassandraPreparedStatement.java, pulled 09/20/2016) . Add the following 2 lines before line 87:
this.cql = cql.replace("WHERE 1=0", "limit 1");
cql = this.cql;
> sparkSession.read() .jdbc(***) use the sql syntax "where 1=0" that Cassandra does not support
> ---------------------------------------------------------------------------------------------
>
> Key: SPARK-17614
> URL: https://issues.apache.org/jira/browse/SPARK-17614
> Project: Spark
> Issue Type: Bug
> Components: SQL
> Affects Versions: 2.0.0
> Environment: Any Spark Runtime
> Reporter: Paul Wu
> Labels: cassandra-jdbc, sql
>
> I have the code like the following with Cassandra JDBC (https://github.com/adejanovski/cassandra-jdbc-wrapper):
> final String dbTable= "sql_demo";
> Dataset<Row> jdbcDF
> = sparkSession.read()
> .jdbc(CASSANDRA_CONNECTION_URL, dbTable, connectionProperties);
> List<Row> rows = jdbcDF.collectAsList();
> It threw the error:
> Exception in thread "main" java.sql.SQLTransientException: com.datastax.driver.core.exceptions.SyntaxError: line 1:29 no viable alternative at input '1' (SELECT * FROM sql_demo WHERE [1]...)
> at com.github.adejanovski.cassandra.jdbc.CassandraPreparedStatement.<init>(CassandraPreparedStatement.java:108)
> at com.github.adejanovski.cassandra.jdbc.CassandraConnection.prepareStatement(CassandraConnection.java:371)
> at com.github.adejanovski.cassandra.jdbc.CassandraConnection.prepareStatement(CassandraConnection.java:348)
> at com.github.adejanovski.cassandra.jdbc.CassandraConnection.prepareStatement(CassandraConnection.java:48)
> The reason is that the Spark jdbc code uses the sql syntax "where 1=0" somewhere (to get the schema?), but Cassandra does not support this syntax. Not sure how this issue can be resolved...this is because CQL is not standard sql.
> The following log shows more information:
> 16/09/20 13:16:35 INFO CassandraConnection 138: Datacenter: %s; Host: %s; Rack: %s
> 16/09/20 13:16:35 TRACE CassandraPreparedStatement 98: CQL: SELECT * FROM sql_demo WHERE 1=0
> 16/09/20 13:16:35 TRACE RequestHandler 71: [19400322] com.datastax.driver.core.Statement$1@41ccb3b9
> 16/09/20 13:16:35 TRACE RequestHandler 272: [19400322-1] Starting
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