Exemplo n.º 1
0
 /**
  * Derives the list of column names suitable for NATURAL JOIN. These are the columns that occur
  * exactly once on each side of the join.
  *
  * @param leftRowType Row type of left input to the join
  * @param rightRowType Row type of right input to the join
  * @return List of columns that occur once on each side
  */
 public static List<String> deriveNaturalJoinColumnList(
     RelDataType leftRowType, RelDataType rightRowType) {
   List<String> naturalColumnNames = new ArrayList<String>();
   final List<String> leftNames = leftRowType.getFieldNames();
   final List<String> rightNames = rightRowType.getFieldNames();
   for (String name : leftNames) {
     if ((Collections.frequency(leftNames, name) == 1)
         && (Collections.frequency(rightNames, name) == 1)) {
       naturalColumnNames.add(name);
     }
   }
   return naturalColumnNames;
 }
Exemplo n.º 2
0
 public static RelDataType createTypeFromProjection(
     RelDataType type,
     List<String> columnNameList,
     RelDataTypeFactory typeFactory,
     boolean caseSensitive) {
   // If the names in columnNameList and type have case-sensitive differences,
   // the resulting type will use those from type. These are presumably more
   // canonical.
   final List<RelDataTypeField> fields = new ArrayList<RelDataTypeField>(columnNameList.size());
   for (String name : columnNameList) {
     RelDataTypeField field = type.getField(name, caseSensitive);
     fields.add(type.getFieldList().get(field.getIndex()));
   }
   return typeFactory.createStructType(fields);
 }
Exemplo n.º 3
0
 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()
                 + "'");
       }
     }
   }
 }
Exemplo n.º 4
0
  /**
   * Looks up a field with a given name, returning null if not found.
   *
   * @param rowType Row type
   * @param columnName Field name
   * @return Field, or null if not found
   */
  public static RelDataTypeField lookupField(
      boolean caseSensitive, final RelDataType rowType, String columnName) {
    RelDataTypeField field = rowType.getField(columnName, caseSensitive);
    if (field != null) {
      return field;
    }

    // If record type is flagged as having "any field you ask for",
    // return a type. (TODO: Better way to mark accommodating types.)
    RelDataTypeField extra = RelDataTypeImpl.extra(rowType);
    if (extra != null) {
      return new RelDataTypeFieldImpl(columnName, -1, extra.getType());
    }
    return null;
  }
Exemplo n.º 5
0
 /**
  * Returns the "extra" field in a row type whose presence signals that fields will come into
  * existence just by asking for them.
  *
  * @param rowType Row type
  * @return The "extra" field, or null
  */
 public static RelDataTypeField extra(RelDataType rowType) {
   // Even in a case-insensitive connection, the name must be precisely
   // "_extra".
   return rowType.getField("_extra", true);
 }
  /**
   * 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())));
  }