apache/shardingsphere · error · SQLFeatureNotSupportedException

getMetaData

Error message

getMetaData

What it means

SQLFeatureNotSupportedException('getMetaData') thrown by AbstractUnsupportedOperationPreparedStatement.getMetaData(). ShardingSphere resolves the actual target database only at execution time (routing depends on bind values and sharding rules), so it cannot produce a ResultSetMetaData for a PreparedStatement before execution; the method is final and always throws. ShardingSpherePreparedStatement computes column metadata only after executing (columnLabelAndIndexMap).

Source

Thrown at jdbc/src/main/java/org/apache/shardingsphere/driver/jdbc/unsupported/AbstractUnsupportedOperationPreparedStatement.java:44

import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.RowId;
import java.sql.SQLException;
import java.sql.SQLFeatureNotSupportedException;

/**
 * Unsupported {@code PreparedStatement} methods.
 */
public abstract class AbstractUnsupportedOperationPreparedStatement extends AbstractStatementAdapter implements PreparedStatement {
    
    @Override
    public final void addBatch(final String sql) throws SQLException {
        throw new SQLFeatureNotSupportedException("addBatch sql in PreparedStatement");
    }
    
    @Override
    public final ResultSetMetaData getMetaData() throws SQLException {
        throw new SQLFeatureNotSupportedException("getMetaData");
    }
    
    @Override
    public final void setNString(final int parameterIndex, final String x) throws SQLException {
        throw new SQLFeatureNotSupportedException("setNString");
    }
    
    @Override
    public final void setNClob(final int parameterIndex, final NClob x) throws SQLException {
        throw new SQLFeatureNotSupportedException("setNClob");
    }
    
    @Override
    public final void setNClob(final int parameterIndex, final Reader x) throws SQLException {
        throw new SQLFeatureNotSupportedException("setNClob");
    }
    
    @Override

View on GitHub (pinned to e952770a21)

Solutions

1. Execute the query first and call rs.getMetaData() on the returned ResultSet — ShardingSphere delegates that to the routed backend.
2. For exporters, switch to a lazy header model that reads metadata from row 1 / ResultSet after execution.
3. Catch SQLFeatureNotSupportedException and defer metadata retrieval to post-execution.

Example fix

// before
ResultSetMetaData md = ps.getMetaData();
int cols = md.getColumnCount();
ResultSet rs = ps.executeQuery();

// after
ResultSet rs = ps.executeQuery();
int cols = rs.getMetaData().getColumnCount();

// ShardingSphere resolves columns only after execution: read metadata from the ResultSet
// if (!driverName.contains("shardingsphere")) use ps.getMetaData(), else execute first

ResultSetMetaData md;
try { md = ps.getMetaData(); }
catch (final SQLFeatureNotSupportedException e) { md = null; } // re-read from rs.getMetaData() after execute

When it happens

Trigger: ps.getMetaData() before ps.executeQuery()/executeUpdate() on a ShardingSphere PreparedStatement. Common in frameworks that pre-render column headers from PreparedStatement metadata (report tools, table models) and in pagination code that counts result columns first.

Common situations: Swing/SWT table models or Excel/CSV exporters built on PreparedStatement.getMetaData; JasperReports subreports; migration from drivers with server-side prepare (PostgreSQL, Oracle) where getMetaData worked pre-execution.

Related errors

• setNString
• setNClob
• setNCharacterStream
• setRowId
• setRef

AI-assisted analysis of apache/shardingsphere@e952770a21 (2026-08-14). Data as JSON: /api/errors/12175bbcd93a1192. Report an issue: GitHub.