Example usage for java.sql DatabaseMetaData getVersionColumns

Introduction

In this page you can find the example usage for java.sql DatabaseMetaData getVersionColumns.

Prototype

ResultSet getVersionColumns(String catalog, String schema, String table) throws SQLException;

Source Link

Document

Retrieves a description of a table's columns that are automatically updated when any value in a row is updated.

Usage

From source file:org.apache.ddlutils.task.DumpMetadataTask.java

/**
 * Dumps the versioned (auto-updating) columns of the indicated table.
 * /*from   w ww.  j  a  va2 s.c o  m*/
 * @param xmlWriter   The xml writer to write to
 * @param metaData    The database metadata
 * @param catalogName The catalog name
 * @param schemaName  The schema name
 * @param tableName   The table name
 */
private void dumpVersionColumns(PrettyPrintingXmlWriter xmlWriter, final DatabaseMetaData metaData,
        final String catalogName, final String schemaName, final String tableName) throws SQLException {
    performResultSetXmlOperation(xmlWriter, null, new ResultSetXmlOperation() {
        public ResultSet getResultSet() throws SQLException {
            return metaData.getVersionColumns(catalogName, schemaName, tableName);
        }

        public void handleRow(PrettyPrintingXmlWriter xmlWriter, ResultSet result) throws SQLException {
            Set columns = getColumnsInResultSet(result);
            String columnName = result.getString("COLUMN_NAME");

            if ((columnName != null) && (columnName.length() > 0)) {
                xmlWriter.writeElementStart(null, "versionedColumn");
                xmlWriter.writeAttribute(null, "column", columnName);

                addIntAttribute(xmlWriter, "typeCode", result, columns, "DATA_TYPE");
                addStringAttribute(xmlWriter, "type", result, columns, "TYPE_NAME");
                addIntAttribute(xmlWriter, "size", result, columns, "BUFFER_LENGTH");
                addIntAttribute(xmlWriter, "precision", result, columns, "COLUMN_SIZE");
                addShortAttribute(xmlWriter, "scale", result, columns, "DECIMAL_DIGITS");
                if (columns.contains("PSEUDO_COLUMN")) {
                    try {
                        switch (result.getShort("PSEUDO_COLUMN")) {
                        case DatabaseMetaData.versionColumnPseudo:
                            xmlWriter.writeAttribute(null, "columnType", "pseudo column");
                            break;
                        case DatabaseMetaData.versionColumnNotPseudo:
                            xmlWriter.writeAttribute(null, "columnType", "real column");
                            break;
                        default:
                            xmlWriter.writeAttribute(null, "columnType", "unknown");
                            break;
                        }
                    } catch (SQLException ex) {
                        log("Could not read the PSEUDO_COLUMN value for versioned colum '" + columnName
                                + "' of table '" + tableName + "' from the result set: " + ex.getStackTrace(),
                                Project.MSG_ERR);
                    }
                }
                xmlWriter.writeElementEnd();
            }
        }

        public void handleError(SQLException ex) {
            log("Could not read the versioned columns for table '" + tableName + "' from the result set: "
                    + ex.getStackTrace(), Project.MSG_ERR);
        }
    });
}

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