apache/seatunnel · warning

Failed to query table schema: {}

Error message

Failed to query table schema: {}

What it means

Logged by DatabendSinkWriter.queryTableSchema() when querying Databend's information/schema for the target table's columns throws any exception. The method returns null on failure, and callers fall back to schema inference. Because this is a warn (not throw), a transient query failure silently degrades the writer to inferred column names.

Source

Thrown at seatunnel-connectors-v2/connector-databend/src/main/java/org/apache/seatunnel/connectors/seatunnel/databend/sink/DatabendSinkWriter.java:584

                while (rs.next()) {
                    String columnName = rs.getString("Field");
                    String columnType = rs.getString("Type");

                    fieldNames.add(columnName);
                    fieldTypes.add(convertDatabendTypeNameToSeaTunnelType(columnType));

                    log.info("Found column: {} {}", columnName, columnType);
                }

                if (!fieldNames.isEmpty()) {
                    return new SeaTunnelRowType(
                            fieldNames.toArray(new String[0]),
                            fieldTypes.toArray(new SeaTunnelDataType<?>[0]));
                }
            }
        } catch (Exception e) {
            log.warn("Failed to query table schema: {}", e.getMessage());
        }
        return null;
    }

    private SeaTunnelDataType<?> convertDatabendTypeNameToSeaTunnelType(String typeName) {
        if (typeName == null) {
            return BasicType.STRING_TYPE;
        }

        typeName = typeName.toUpperCase();

        if (typeName.contains("VARCHAR")
                || typeName.contains("STRING")
                || typeName.contains("TEXT")) {
            return BasicType.STRING_TYPE;
        } else if (typeName.contains("INT") && !typeName.contains("BIGINT")) {
            return BasicType.INT_TYPE;
        } else if (typeName.contains("BIGINT")) {

View on GitHub (pinned to cf67b549a7)

Solutions

1. Verify the configured database/table names are correct and the table exists before starting the job
2. Grant the Databend user permission to read information_schema / describe the table
3. Ensure the JDBC connection URL and credentials are valid; test with a manual DESC table
4. Check the logged exception message for the root SQL error (only e.getMessage() is logged) and fix accordingly

Example fix

// before
} catch (Exception e) {
    log.warn("Failed to query table schema: {}", e.getMessage());
}
// after
} catch (Exception e) {
    log.warn("Failed to query table schema: {}", e.getMessage(), e);
    throw new DatabendConnectorException(DatabendConnectorErrorCode.SCHEMA_NOT_FOUND, e);
}

// pre-check metadata access before running the job
try (Connection c = DriverManager.getConnection(url, user, pass);
     Statement s = c.createStatement()) {
    s.executeQuery("DESC " + database + "." + table);
}

boolean schemaQueryable(String db, String tbl) {
    try (Connection c = DriverManager.getConnection(url, user, pass);
         Statement s = c.createStatement()) {
        s.executeQuery("SELECT 1 FROM information_schema.tables WHERE table_schema='" + db + "' AND table_name='" + tbl + "' AND 1=0");
        return true;
    } catch (SQLException e) { return false; }
}

try {
    SeaTunnelRowType t = queryTableSchema();
} catch (Exception e) {
    // writer already returns null; provide explicit schema instead of relying on inference
}

When it happens

Trigger: The JDBC metadata query (e.g. DESC/information_schema.columns) fails: bad connection, missing SELECT privilege on information_schema, wrong database/table name, or table not yet created (auto-create race).

Common situations: Typo in table/database name; user lacks metadata privileges; auto_create_table enabled so the table doesn't exist yet at first schema lookup; network error to Databend.

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

• SQL_OPERATION_FAILED
• Failed to read schema for table %s
• Error reading default database charsets: ${e.getMessage()}
• Failed to read schema for table ${tableId}
• Failed to read schema for table ${tableId}

AI-assisted analysis of apache/seatunnel@cf67b549a7 (2026-09-10). Data as JSON: /api/errors/41249f89abf0432a. Report an issue: GitHub.