apache/beam · error · ParseException

Unable to parse statement

Error message

Unable to parse statement

What it means

BeamSqlEnv.explain converts a SQL string to a Beam relational plan for EXPLAIN output. Any failure anywhere in planning/parsing/validation (not just syntax) is wrapped as a ParseException with the fixed message 'Unable to parse statement' and the original cause attached.

Source

Thrown at sdks/java/extensions/sql/src/main/java/org/apache/beam/sdk/extensions/sql/impl/BeamSqlEnv.java:152

  }

  /**
   * Registers a custom {@link SqlOperator} into the current session's operator table. This allows
   * registering functions with non-fixed operand types (e.g. VARIADIC), which the schema-function
   * auto-wrapping mechanism cannot express.
   *
   * <p>Only safe to call before the first SQL query is planned in this environment (otherwise the
   * parser/validator operator table may have already been built without it).
   */
  public void registerSqlOperator(SqlOperator operator) {
    connection.getExtraOperatorTable().add(operator);
  }

  public String explain(String sqlString) throws ParseException {
    try {
      return RelOptUtil.toString(planner.convertToBeamRel(sqlString, QueryParameters.ofNone()));
    } catch (Exception e) {
      throw new ParseException("Unable to parse statement", e);
    }
  }

  /** BeamSqlEnv's Builder. */
  public static class BeamSqlEnvBuilder {
    private static final String CALCITE_PLANNER =
        "org.apache.beam.sdk.extensions.sql.impl.CalciteQueryPlanner";
    private String queryPlannerClassName;
    private CatalogManager catalogManager;
    private @Nullable String currentSchemaName = null;
    private Map<String, TableProvider> schemaMap;
    private Set<Map.Entry<String, Function>> functionSet;
    private boolean autoLoadUdfs;
    private @Nullable PipelineOptions pipelineOptions;
    private Collection<RuleSet> ruleSets;

    private BeamSqlEnvBuilder(TableProvider tableProvider) {
      if (tableProvider instanceof MetaStore) {

View on GitHub (pinned to 12126d8942)

Solutions

1. Read the attached cause (e.getCause()) to see the real parse/validate error
2. Validate the SQL runs via parseQuery/executeQuery or the JDBC driver first
3. Register all schemas/tables referenced by the query before explaining
4. Fix SQL syntax per Calcite dialect (double quotes for identifiers, etc.)

Example fix

// before
env.explain("SELEC * FROM t");
// after
env.explain("SELECT * FROM t");

// validate SQL by parsing first
env.parseQuery(sqlString);

try { return env.explain(sql); } catch (ParseException e) { log.error("Plan failed for '{}'", sql, e.getCause()); throw e; }

When it happens

Trigger: Calling BeamSqlEnv.explain(sql) where the SQL has syntax errors, references unknown tables/schemas, or fails any Calcite validation/optimization step.

Common situations: Typos in SQL, missing registered schema/table for the query, functions not found, malformed table provider config — all surface under this single message.

Understand the failure class

Background: "query failed", "%w: SQL error" — wrapped database query errors in Go libraries explained — this error's family across 3 libraries.

• Parsing and encoding errors: unexpected token, malformed input — why parsers reject input and how to find the real culprit.

Related errors

• illegal table properties: ${json}
• Beam JDBC connection has not been initialized
• Unable to parse query %s
• Failed to infer Beam schema
• Unable to create prepared statement for type: ${type}

AI-assisted analysis of apache/beam@12126d8942 (2026-09-13). Data as JSON: /api/errors/b6dceeb4ccb935b5. Report an issue: GitHub.