ColumnAliasExtractor (Hibernate Javadocs)

Functional Interface:: This is a functional interface and can therefore be used as the assignment target for a lambda expression or method reference.

@SPI({USE,IMPLEMENT,SUPPLY}) @FunctionalInterface public interface ColumnAliasExtractor

Extracts the unique result-column alias used while auto-discovering native SQL query results.

Use COLUMN_LABEL_EXTRACTOR for JDBC drivers which correctly report the projected alias through ResultSetMetaData.getColumnLabel(int). Use COLUMN_NAME_EXTRACTOR only for drivers which require ResultSetMetaData.getColumnName(int) instead. The supplied position is the one-based JDBC column position and must be forwarded unchanged.

Implementations must propagate SQLException so Hibernate can apply its normal JDBC exception handling.

Since:

8.0

See Also:

Field Summary

Fields

Modifier and Type

Field

Description

static final ColumnAliasExtractor

COLUMN_LABEL_EXTRACTOR

The stock extractor which calls ResultSetMetaData.getColumnLabel(int).

static final ColumnAliasExtractor

COLUMN_NAME_EXTRACTOR

The stock extractor which calls ResultSetMetaData.getColumnName(int).
Method Summary

Modifier and Type

Method

Description

String

extractColumnAlias(ResultSetMetaData metaData, int position)

Extract the alias at the given one-based JDBC column position.

Field Details
- COLUMN_LABEL_EXTRACTOR
  
  static final ColumnAliasExtractor COLUMN_LABEL_EXTRACTOR
  
  The stock extractor which calls ResultSetMetaData.getColumnLabel(int).
- COLUMN_NAME_EXTRACTOR
  
  static final ColumnAliasExtractor COLUMN_NAME_EXTRACTOR
  
  The stock extractor which calls ResultSetMetaData.getColumnName(int).
Method Details
- extractColumnAlias
  
  String extractColumnAlias(ResultSetMetaData metaData, int position) throws SQLException
  
  Extract the alias at the given one-based JDBC column position.
  
  Parameters:
  
  metaData - the result-set metadata
  
  position - the one-based JDBC column position
  
  Returns:
  
  the reported alias
  
  Throws:
  
  SQLException - when the driver cannot access the metadata