apache/shardingsphere · error · SQLFeatureNotSupportedException

getClob

Error message

getClob

What it means

getClob(int columnIndex) always throws SQLFeatureNotSupportedException("getClob") in AbstractUnsupportedGeneratedKeysResultSet:202, the parent of ShardingSphere's GeneratedKeysResultSet. Generated keys are held as an in-memory iterator of numeric values, so there is no CLOB to return and the accessor is explicitly unsupported rather than returning null.

Source

Thrown at jdbc/src/main/java/org/apache/shardingsphere/driver/jdbc/unsupported/AbstractUnsupportedGeneratedKeysResultSet.java:202

    
    @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
    public final URL getURL(final int columnIndex) throws SQLException {
        throw new SQLFeatureNotSupportedException("getURL");
    }
    
    @Override
    public final URL getURL(final String columnLabel) throws SQLException {
        throw new SQLFeatureNotSupportedException("getURL");
    }
    
    @Override

View on GitHub (pinned to e952770a21)

Solutions

1. Use keys.getString(1)/keys.getLong(1) instead.
2. Gate CLOB handling to SELECT result sets; never run it on generated-keys output.
3. If character payload is needed, SELECT it afterward using the generated key.
4. In adapters, catch SQLFeatureNotSupportedException and retry with getString(1).

Example fix

// before
Clob c = keys.getClob(1);

// after
String id = keys.getString(1);

int type = keys.getMetaData().getColumnType(1);
if (type != Types.CLOB) { String id = keys.getString(1); }

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

try {
    Clob c = rs.getClob(1);
} catch (SQLFeatureNotSupportedException e) {
    String v = rs.getString(1);
}

When it happens

Trigger: Calling resultSet.getClob(1) on the keys ResultSet from getGeneratedKeys() — often from generic mappers whose metadata inspection of the key column steers them into CLOB handling, or from code that reads all columns as LOBs first.

Common situations: Legacy CLOB-based text handling applied to every result set; data-export pipelines; apps previously on native drivers where getClob on generated keys threw a friendlier error or returned null — after adopting ShardingSphere-JDBC the SQLFeatureNotSupportedException surfaces at the same call site.

Related errors

• getBlob
• getUnicodeStream
• getBinaryStream
• getWarnings
• clearWarnings

AI-assisted analysis of apache/shardingsphere@e952770a21 (2026-08-14). Data as JSON: /api/errors/b0fecb912a77cde8. Report an issue: GitHub.