Пример #1
0
  /**
   * Creates a string in a specfied character set.
   *
   * @param value String constant, must not be null
   * @param charsetName Name of the character set, may be null
   * @param collation Collation, may be null
   * @throws IllegalCharsetNameException If the given charset name is illegal
   * @throws UnsupportedCharsetException If no support for the named charset is available in this
   *     instance of the Java virtual machine
   * @throws RuntimeException If the given value cannot be represented in the given charset
   */
  public NlsString(String value, String charsetName, SqlCollation collation) {
    assert value != null;
    if (null != charsetName) {
      charsetName = charsetName.toUpperCase();
      this.charsetName = charsetName;
      String javaCharsetName = SqlUtil.translateCharacterSetName(charsetName);
      if (javaCharsetName == null) {
        throw new UnsupportedCharsetException(charsetName);
      }
      this.charset = Charset.forName(javaCharsetName);
      CharsetEncoder encoder = charset.newEncoder();

      // dry run to see if encoding hits any problems
      try {
        encoder.encode(CharBuffer.wrap(value));
      } catch (CharacterCodingException ex) {
        throw RESOURCE.charsetEncoding(value, javaCharsetName).ex();
      }
    } else {
      this.charsetName = null;
      this.charset = null;
    }
    this.collation = collation;
    this.value = value;
  }
Пример #2
0
  /**
   * Derives an alias for a node, and invents a mangled identifier if it cannot.
   *
   * <p>Examples:
   *
   * <ul>
   *   <li>Alias: "1 + 2 as foo" yields "foo"
   *   <li>Identifier: "foo.bar.baz" yields "baz"
   *   <li>Anything else yields "expr$<i>ordinal</i>"
   * </ul>
   *
   * @return An alias, if one can be derived; or a synthetic alias "expr$<i>ordinal</i>" if ordinal
   *     >= 0; otherwise null
   */
  public static String getAlias(SqlNode node, int ordinal) {
    switch (node.getKind()) {
      case AS:
        // E.g. "1 + 2 as foo" --> "foo"
        return ((SqlCall) node).getOperands()[1].toString();

      case OVER:
        // E.g. "bids over w" --> "bids"
        return getAlias(((SqlCall) node).getOperands()[0], ordinal);

      case IDENTIFIER:
        // E.g. "foo.bar" --> "bar"
        return Util.last(((SqlIdentifier) node).names);

      default:
        if (ordinal < 0) {
          return null;
        } else {
          return SqlUtil.deriveAliasFromOrdinal(ordinal);
        }
    }
  }