apache/seatunnel · error · SeaTunnelException

Table %s field %s duplicate

Error message

Table %s field %s duplicate

What it means

Thrown by TableFactoryContext.checkCatalogTableIllegal when the same field name appears more than once in a CatalogTable's schema. Duplicate column names are ambiguous for row-type resolution and downstream column mapping, so the factory context rejects the table before plugin creation.

Source

Thrown at seatunnel-api/src/main/java/org/apache/seatunnel/api/table/factory/TableFactoryContext.java:53

    private final ClassLoader classLoader;

    public TableFactoryContext(ReadonlyConfig options, ClassLoader classLoader) {
        this.options = options;
        this.classLoader = classLoader;
    }

    protected static void checkCatalogTableIllegal(List<CatalogTable> catalogTables) {
        for (CatalogTable catalogTable : catalogTables) {
            List<String> alreadyChecked = new ArrayList<>();
            for (String fieldName : catalogTable.getTableSchema().getFieldNames()) {
                if (StringUtils.isBlank(fieldName)) {
                    throw new SeaTunnelException(
                            String.format(
                                    "Table %s field name cannot be empty",
                                    catalogTable.getTablePath().getFullName()));
                }
                if (alreadyChecked.contains(fieldName)) {
                    throw new SeaTunnelException(
                            String.format(
                                    "Table %s field %s duplicate",
                                    catalogTable.getTablePath().getFullName(), fieldName));
                }
                alreadyChecked.add(fieldName);
            }
        }
    }
}

View on GitHub (pinned to cf67b549a7)

Solutions

1. Remove or rename the duplicate field in the schema so all names are unique.
2. Use a Transform (e.g. Replace/SQL) to rename one of the colliding upstream columns before the sink.
3. If building CatalogTable in code, de-duplicate field names when constructing TableSchema.
4. Check which connector/catalog produced the duplicated column and fix its column derivation.

Example fix

// before
schema { fields { name = string, name = int, id = long } }
// after
schema { fields { name = string, age = int, id = long } }

Set<String> seen = new HashSet<>(); for (String n : table.getTableSchema().getFieldNames()) { if (!seen.add(n)) throw new IllegalArgumentException("duplicate field: " + n); }

boolean hasDuplicate = Arrays.stream(schema.getFieldNames()).distinct().count() != (schema.getFieldNames() == null ? 0 : schema.getFieldNames().length);

try { factory.createAndPrepareSource(...) } catch (SeaTunnelException e) { if (e.getMessage().contains("duplicate")) { log.error("duplicate schema field: {}", e.getMessage()); } throw e; }

When it happens

Trigger: Calling TableFactoryContext (via createAndPrepareSource/Sink/Transform) with a CatalogTable whose TableSchema.getFieldNames() contains a repeated name — e.g. a schema block declaring 'name' twice, or a catalog merging multiple upstream column definitions under the same key.

Common situations: Copy-paste errors in hand-written schema blocks; CDC pipelines where a renamed column collides with an existing one; connector catalog code that appends columns without de-duplicating; multi-table configs where a shared schema fragment is merged twice.

Understand the failure class

Background: Schema validation failed / invalid input schema: payload rejected because its shape doesn't match the expected schema — this error's family across 28 libraries.

Related errors

• Table %s field name cannot be empty
• Operator %s requires a compareOption (cross-field comparison
• Schema config can not be empty
• Streaming mode requires a Primary Key in the schema of table
• FIELD_NOT_IN_TABLE

AI-assisted analysis of apache/seatunnel@cf67b549a7 (2026-09-10). Data as JSON: /api/errors/68e9a67793748bae. Report an issue: GitHub.