/**
   * Returns true if a type is a simple cast of another type. It is if the cast type is nullable and
   * the cast is one of the following:
   * <li>x TO x
   * <li>char(n) TO varchar(m)
   * <li>varchar(n) TO varchar(m)
   * <li>x not null TO x nullable
   *
   * @param origType original type passed into the cast operand
   * @param castType type the operand will be casted to
   * @return true if the cast is simple
   */
  private boolean isCastSimple(RelDataType origType, RelDataType castType) {
    SqlTypeName origTypeName = origType.getSqlTypeName();
    SqlTypeName castTypeName = castType.getSqlTypeName();

    if (!(castType.isNullable())) {
      return false;
    }

    Charset origCharset = origType.getCharset();
    Charset castCharset = castType.getCharset();
    if ((origCharset != null) || (castCharset != null)) {
      if ((origCharset == null) || (castCharset == null)) {
        return false;
      }
      if (!origCharset.equals(castCharset)) {
        return false;
      }
    }

    return ((origType == castType)
        || ((origTypeName == SqlTypeName.CHAR) && (castTypeName == SqlTypeName.VARCHAR))
        || ((origTypeName == SqlTypeName.VARCHAR) && (castTypeName == SqlTypeName.VARCHAR))
        || ((origTypeName == castTypeName)
            && (origType.getPrecision() == castType.getPrecision())
            && ((origTypeName != SqlTypeName.DECIMAL)
                || (origType.getScale() == castType.getScale()))
            && (!origType.isNullable() && castType.isNullable())));
  }
Beispiel #2
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 public static void checkCharsetAndCollateConsistentIfCharType(RelDataType type) {
   // (every charset must have a default collation)
   if (SqlTypeUtil.inCharFamily(type)) {
     Charset strCharset = type.getCharset();
     Charset colCharset = type.getCollation().getCharset();
     assert null != strCharset;
     assert null != colCharset;
     if (!strCharset.equals(colCharset)) {
       if (false) {
         // todo: enable this checking when we have a charset to
         //   collation mapping
         throw new Error(
             type.toString()
                 + " was found to have charset '"
                 + strCharset.name()
                 + "' and a mismatched collation charset '"
                 + colCharset.name()
                 + "'");
       }
     }
   }
 }