apache/shardingsphere · error · UnsupportedOperationException

Unsupported Simple Expression

Error message

Unsupported Simple Expression

What it means

Thrown by OracleDMLStatementVisitor.createProjectionForSimpleExpressionSegment when a 'simple' projection is neither SubqueryExpressionSegment nor LiteralExpressionSegment. The UnsupportedOperationException('Unsupported Simple Expression') is a narrow coverage gap: only subqueries and literals are handled as simple expressions in this branch.

Source

Thrown at parser/sql/engine/dialect/oracle/src/main/java/org/apache/shardingsphere/sql/parser/engine/oracle/visitor/statement/type/OracleDMLStatementVisitor.java:1169

    }
    
    private ASTNode createProjectionForSimpleExpressionSegment(final ASTNode projection, final AliasSegment alias, final SelectProjectionExprClauseContext ctx) {
        if (projection instanceof SubqueryExpressionSegment) {
            SubqueryExpressionSegment subqueryExpressionSegment = (SubqueryExpressionSegment) projection;
            String text = ctx.start.getInputStream().getText(new Interval(subqueryExpressionSegment.getStartIndex(), subqueryExpressionSegment.getStopIndex()));
            SubqueryProjectionSegment result = new SubqueryProjectionSegment(((SubqueryExpressionSegment) projection).getSubquery(), text);
            result.setAlias(alias);
            return result;
        }
        if (projection instanceof LiteralExpressionSegment) {
            LiteralExpressionSegment column = (LiteralExpressionSegment) projection;
            ExpressionProjectionSegment result = null == alias
                    ? new ExpressionProjectionSegment(column.getStartIndex(), column.getStopIndex(), column.getText(), column)
                    : new ExpressionProjectionSegment(column.getStartIndex(), ctx.alias().stop.getStopIndex(), column.getText(), column);
            result.setAlias(alias);
            return result;
        }
        throw new UnsupportedOperationException("Unsupported Simple Expression");
    }
    
    private ASTNode createProjectionForExpressionSegment(final ASTNode projection, final AliasSegment alias) {
        // FIXME :For DISTINCT()
        if (projection instanceof ColumnSegment) {
            return createColumnProjectionSegment((ColumnSegment) projection, alias);
        }
        if (projection instanceof BinaryOperationExpression) {
            return createExpressionProjectionSegment((BinaryOperationExpression) projection, alias);
        }
        if (projection instanceof MultisetExpression) {
            return createExpressionProjectionSegment((MultisetExpression) projection, alias);
        }
        if (projection instanceof DatetimeExpression) {
            return createDatetimeProjectionSegment((DatetimeExpression) projection);
        }
        if (projection instanceof IntervalExpressionProjection) {
            return createIntervalExpressionProjection((IntervalExpressionProjection) projection);

View on GitHub (pinned to e952770a21)

Solutions

1. Replace the expression with a literal or move it into a subquery projection form
2. Check whether a newer ShardingSphere version adds the missing simple-expression branch
3. Reproduce with a minimal SELECT and file an upstream issue including the statement

try { parserEngine.parse(sql); } catch (UnsupportedOperationException e) { throw new StatementUnsupportedException(sql, e); }

When it happens

Trigger: A projection routed here (via the SimpleExpressionSegment branch in 613) whose concrete node is not a subquery or literal — e.g. a parameter marker or variable expression classified as 'simple' by an instanceof on a marker interface but lacking a dedicated branch here.

Common situations: Prepared statements with ? markers in unusual projection positions; bind-variable-heavy Oracle SQL; upgrades that reclassify segments under the SimpleExpressionSegment hierarchy.

Related errors

• Unhandled case
• Unsupported Complex Expression
• Unsupported Expression
• Unsupported Returning Expression
• Projections not in simple select, table subquery, join subqu

AI-assisted analysis of apache/shardingsphere@e952770a21 (2026-08-14). Data as JSON: /api/errors/55584afd57f15c7a. Report an issue: GitHub.