presto-base-jdbc/src/main/java/io/prestosql/plugin/jdbc/BaseJdbcClient.java/BaseJdbcClient/getColumnSql
class BaseJdbcClient:    private String getColumnSql(ConnectorSession session, ColumnMetadata column, String columnName)
    {
        StringBuilder sb = new StringBuilder()
                .append(quoted(columnName))
                .append(" ")
                .append(toWriteMapping(session, column.getType()).getDataType());
        if (!column.isNullable()) {
            sb.append(" NOT NULL");
        }
        return sb.toString();
    }