apache/shardingsphere · error · SQLFeatureNotSupportedException

getBlob

Error message

getBlob

What it means

getBlob(int columnIndex) unconditionally throws SQLFeatureNotSupportedException("getBlob") in AbstractUnsupportedGeneratedKeysResultSet:192. ShardingSphere's GeneratedKeysResultSet (the object you get from getGeneratedKeys()) exposes one synthesized numeric key column; LOB accessors are unimplemented because there is no large-object backing store behind the keys.

Source

Thrown at jdbc/src/main/java/org/apache/shardingsphere/driver/jdbc/unsupported/AbstractUnsupportedGeneratedKeysResultSet.java:192

    
    @Override
    public final int getFetchDirection() throws SQLException {
        throw new SQLFeatureNotSupportedException("getFetchDirection");
    }
    
    @Override
    public final void setFetchSize(final int rows) throws SQLException {
        throw new SQLFeatureNotSupportedException("setFetchSize");
    }
    
    @Override
    public final int getFetchSize() throws SQLException {
        throw new SQLFeatureNotSupportedException("getFetchSize");
    }
    
    @Override
    public final Blob getBlob(final int columnIndex) throws SQLException {
        throw new SQLFeatureNotSupportedException("getBlob");
    }
    
    @Override
    public final Blob getBlob(final String columnLabel) throws SQLException {
        throw new SQLFeatureNotSupportedException("getBlob");
    }
    
    @Override
    public final Clob getClob(final int columnIndex) throws SQLException {
        throw new SQLFeatureNotSupportedException("getClob");
    }
    
    @Override
    public final Clob getClob(final String columnLabel) throws SQLException {
        throw new SQLFeatureNotSupportedException("getClob");
    }
    
    @Override

View on GitHub (pinned to e952770a21)

Solutions

1. Use getLong(1)/getObject(1) to read the generated key.
2. Ensure LOB type handlers only run against SELECT result sets, not generated-keys result sets.
3. If you truly need a BLOB, fetch it with a subsequent SELECT on the returned key.
4. In unmodifiable third-party code, catch SQLFeatureNotSupportedException and retry with getObject(1).

Example fix

// before
Blob b = keys.getBlob(1);

// after
long id = keys.getLong(1);

int type = keys.getMetaData().getColumnType(1);
if (type == Types.BIGINT || type == Types.INTEGER) { long id = keys.getLong(1); }

private static boolean isGeneratedKeysRs(ResultSet rs) {
    return rs.getClass().getName().endsWith("GeneratedKeysResultSet");
}

try {
    Blob b = rs.getBlob(1);
} catch (SQLFeatureNotSupportedException e) {
    Object key = rs.getObject(1);
}

When it happens

Trigger: Calling resultSet.getBlob(1) on the keys ResultSet — typically a generic mapper that selects getBlob when metadata or heuristics suggest binary data, or copy tools that try LOB accessors first for any column.

Common situations: ORM type handlers (old Hibernate BlobType) applied uniformly to all result sets; ResultSet->ResultSet copying utilities; code that assumed MySQL Connector/J behavior (which would throw or return null differently) after moving to ShardingSphere-JDBC for sharding.

Related errors

• getClob
• getUnicodeStream
• getBinaryStream
• getWarnings
• clearWarnings

AI-assisted analysis of apache/shardingsphere@e952770a21 (2026-08-14). Data as JSON: /api/errors/d4253fae3c019cc7. Report an issue: GitHub.