databasemetadata.java

数据仓库工具

                                             String table) throws SQLException
   {
      NotImplemented(); return null;
   }


   /**
    * Get all the "extra" characters that can be used in unquoted
    * identifier names (those beyond a-z, A-Z, 0-9 and _).
    *
    * @return the string containing the extra characters
    * @exception SQLException if a database-access error occurs.
    */
   public String getExtraNameCharacters() throws SQLException
   {
      return "#$";
   }


   /**
    * What's the string used to quote SQL identifiers?
    * This returns a space " " if identifier quoting isn't supported.
    *
    * A JDBC-Compliant driver always uses a double quote character.
    *
    * @return the quoting string
    * @exception SQLException if a database-access error occurs.
    */
   public String getIdentifierQuoteString() throws SQLException
   {
      return "\"";
   }


   /**
    * Get a description of the primary key columns that are
    * referenced by a table's foreign key columns (the primary keys
    * imported by a table).  They are ordered by PKTABLE_CAT,
    * PKTABLE_SCHEM, PKTABLE_NAME, and KEY_SEQ.
    *
    * <P>Each primary key column description has the following columns:
    *  <OL>
    *   <LI><B>PKTABLE_CAT</B> String => primary key table catalog
    *      being imported (may be null)
    *   <LI><B>PKTABLE_SCHEM</B> String => primary key table schema
    *      being imported (may be null)
    *   <LI><B>PKTABLE_NAME</B> String => primary key table name
    *      being imported
    *   <LI><B>PKCOLUMN_NAME</B> String => primary key column name
    *      being imported
    *   <LI><B>FKTABLE_CAT</B> String => foreign key table catalog (may be null)
    *   <LI><B>FKTABLE_SCHEM</B> String => foreign key table schema (may be null)
    *   <LI><B>FKTABLE_NAME</B> String => foreign key table name
    *   <LI><B>FKCOLUMN_NAME</B> String => foreign key column name
    *   <LI><B>KEY_SEQ</B> short => sequence number within foreign key
    *   <LI><B>UPDATE_RULE</B> short => What happens to
    *       foreign key when primary is updated:
    *      <UL>
    *      <LI> importedNoAction - do not allow update of primary
    *               key if it has been imported
    *      <LI> importedKeyCascade - change imported key to agree
    *               with primary key update
    *      <LI> importedKeySetNull - change imported key to NULL if
    *               its primary key has been updated
    *      <LI> importedKeySetDefault - change imported key to default values
    *               if its primary key has been updated
    *      <LI> importedKeyRestrict - same as importedKeyNoAction
    *                                 (for ODBC 2.x compatibility)
    *      </UL>
    *   <LI><B>DELETE_RULE</B> short => What happens to
    *      the foreign key when primary is deleted.
    *      <UL>
    *      <LI> importedKeyNoAction - do not allow delete of primary
    *               key if it has been imported
    *      <LI> importedKeyCascade - delete rows that import a deleted key
    *      <LI> importedKeySetNull - change imported key to NULL if
    *               its primary key has been deleted
    *      <LI> importedKeyRestrict - same as importedKeyNoAction
    *                                 (for ODBC 2.x compatibility)
    *      <LI> importedKeySetDefault - change imported key to default if
    *               its primary key has been deleted
    *      </UL>
    *   <LI><B>FK_NAME</B> String => foreign key name (may be null)
    *   <LI><B>PK_NAME</B> String => primary key name (may be null)
    *   <LI><B>DEFERRABILITY</B> short => can the evaluation of foreign key
    *      constraints be deferred until commit
    *      <UL>
    *      <LI> importedKeyInitiallyDeferred - see SQL92 for definition
    *      <LI> importedKeyInitiallyImmediate - see SQL92 for definition
    *      <LI> importedKeyNotDeferrable - see SQL92 for definition
    *      </UL>
    *  </OL>
    *
    * @param catalog a catalog name; "" retrieves those without a
    * catalog; null means drop catalog name from the selection criteria
    * @param schema a schema name pattern; "" retrieves those
    * without a schema
    * @param table a table name
    * @return ResultSet - each row is a primary key column description
    * @exception SQLException if a database-access error occurs.
    * @see #getExportedKeys
    */
   public java.sql.ResultSet getImportedKeys(String catalog, String schema,
                                             String table) throws SQLException
   {
      NotImplemented(); return null;
   }


   /**
    * Get a description of a table's indices and statistics. They are
    * ordered by NON_UNIQUE, TYPE, INDEX_NAME, and ORDINAL_POSITION.
    *
    * <P>Each index column description has the following columns:
    *  <OL>
    *   <LI><B>TABLE_CAT</B> String => table catalog (may be null)
    *   <LI><B>TABLE_SCHEM</B> String => table schema (may be null)
    *   <LI><B>TABLE_NAME</B> String => table name
    *   <LI><B>NON_UNIQUE</B> boolean => Can index values be non-unique?
    *      false when TYPE is tableIndexStatistic
    *   <LI><B>INDEX_QUALIFIER</B> String => index catalog (may be null);
    *      null when TYPE is tableIndexStatistic
    *   <LI><B>INDEX_NAME</B> String => index name; null when TYPE is
    *      tableIndexStatistic
    *   <LI><B>TYPE</B> short => index type:
    *      <UL>
    *      <LI> tableIndexStatistic - this identifies table statistics that are
    *           returned in conjuction with a table's index descriptions
    *      <LI> tableIndexClustered - this is a clustered index
    *      <LI> tableIndexHashed - this is a hashed index
    *      <LI> tableIndexOther - this is some other style of index
    *      </UL>
    *   <LI><B>ORDINAL_POSITION</B> short => column sequence number
    *      within index; zero when TYPE is tableIndexStatistic
    *   <LI><B>COLUMN_NAME</B> String => column name; null when TYPE is
    *      tableIndexStatistic
    *   <LI><B>ASC_OR_DESC</B> String => column sort sequence, "A" => ascending,
    *      "D" => descending, may be null if sort sequence is not supported;
    *      null when TYPE is tableIndexStatistic
    *   <LI><B>CARDINALITY</B> int => When TYPE is tableIndexStatistic, then
    *      this is the number of rows in the table; otherwise, it is the
    *      number of unique values in the index.
    *   <LI><B>PAGES</B> int => When TYPE is  tableIndexStatisic then
    *      this is the number of pages used for the table, otherwise it
    *      is the number of pages used for the current index.
    *   <LI><B>FILTER_CONDITION</B> String => Filter condition, if any.
    *      (may be null)
    *  </OL>
    *
    * @param catalog a catalog name; "" retrieves those without a
    * catalog; null means drop catalog name from the selection criteria
    * @param schema a schema name pattern; "" retrieves those without a schema
    * @param table a table name
    * @param unique when true, return only indices for unique values;
    *     when false, return indices regardless of whether unique or not
    * @param approximate when true, result is allowed to reflect approximate
    *     or out of data values; when false, results are requested to be
    *     accurate
    * @return ResultSet - each row is an index column description
    * @exception SQLException if a database-access error occurs.
    */
   public java.sql.ResultSet getIndexInfo(String catalog, String schema, String table,
                                          boolean unique, boolean approximate)
      throws SQLException
   {
      NotImplemented(); return null;
   }


   //----------------------------------------------------------------------
   // The following group of methods exposes various limitations
   // based on the target database with the current driver.
   // Unless otherwise specified, a result of zero means there is no
   // limit, or the limit is not known.

   /**
    * How many hex characters can you have in an inline binary literal?
    *
    * @return max literal length
    * @exception SQLException if a database-access error occurs.
    */
   public int getMaxBinaryLiteralLength() throws SQLException
   {
      // XXX Need to check for Sybase and SQLServer 7.0

      return 131072; // per "Programming ODBC for SQLServer" Appendix A
   }


   /**
    * What's the maximum length of a catalog name?
    *
    * @return max name length in bytes
    * @exception SQLException if a database-access error occurs.
    */
   public int getMaxCatalogNameLength() throws SQLException
   {
      NotImplemented(); return 0;
   }


   /**
    * What's the max length for a character literal?
    *
    * @return max literal length
    * @exception SQLException if a database-access error occurs.
    */
   public int getMaxCharLiteralLength() throws SQLException
   {
      // XXX Need to check for Sybase

      return 131072; // per "Programming ODBC for SQLServer" Appendix A
   }


   /**
    * What's the limit on column name length?
    *
    * @return max literal length
    * @exception SQLException if a database-access error occurs.
    */
   public int getMaxColumnNameLength() throws SQLException
   {
      // XXX Need to check for Sybase

      return 30; // per "Programming ODBC for SQLServer" Appendix A
   }


   /**
    * What's the maximum number of columns in a "GROUP BY" clause?
    *
    * @return max number of columns
    * @exception SQLException if a database-access error occurs.
    */
   public int getMaxColumnsInGroupBy() throws SQLException
   {
      // XXX Need to check for Sybase

      return 16; // per "Programming ODBC for SQLServer" Appendix A
   }


   /**
    * What's the maximum number of columns allowed in an index?
    *
    * @return max columns
    * @exception SQLException if a database-access error occurs.
    */
   public int getMaxColumnsInIndex() throws SQLException
   {
      // XXX need to find out if this is still true for SYBASE

      // per SQL Server Books Online "Administrator's Companion",
      // Part 1, Chapter 1.
      return 16;
   }


   /**
    * What's the maximum number of columns in an "ORDER BY" clause?
    *
    * @return max columns
    * @exception SQLException if a database-access error occurs.
    */
   public int getMaxColumnsInOrderBy() throws SQLException
   {
      // XXX Need to check for Sybase

      return 16; // per "Programming ODBC for SQLServer" Appendix A
   }


   /**
    * What's the maximum number of columns in a "SELECT" list?
    *
    * @return max columns
    * @exception SQLException if a database-access error occurs.
    */
   public int getMaxColumnsInSelect() throws SQLException
   {
      // XXX Need to check for Sybase

      return 4000; // per "Programming ODBC for SQLServer" Appendix A
   }


   /**
    * What's the maximum number of columns in a table?
    *
    * @return max columns
    * @exception SQLException if a database-access error occurs.
    */
   public int getMaxColumnsInTable() throws SQLException
   {
      // XXX How do we find this out for Sybase?
      return 250; // per "Programming ODBC for SQLServer" Appendix A
   }


   /**
    * How many active connections can we have at a time to this database?
    *
    * @return max connections
    * @exception SQLException if a database-access error occurs.
    */
   public int getMaxConnections() throws SQLException
   {
      // XXX need to find out if this is still true for SYBASE

      // per SQL Server Books Online "Administrator's Companion",
      // Part 1, Chapter 1.
      return 32767;
   }


   /**
    * What's the maximum cursor name length?
    *
    * @return max cursor name length in bytes
    * @exception SQLException if a database-access error occurs.
    */
   public int getMaxCursorNameLength() throws SQLException
   {
      // XXX Need to check for Sybase

      return 30; // per "Programming ODBC for SQLServer" Appendix A
   }


   /**
    * What's the maximum length of an index (in bytes)?
    *
    * @return max index length in bytes
    * @exception SQLException if a database-access error occurs.
    */
   public int getMaxIndexLength() throws SQLException
   {
      // XXX Need to check for Sybase

      return 900; // per "Programming ODBC for SQLServer" Appendix A
   }


   /**
    * What's the maximum length of a procedure name?
    *
    * @return max name length in bytes
    * @exception SQLException if a database-access error occurs.
    */
   public int getMaxProcedureNameLength() throws SQLException
   {
      // XXX Need to check for Sybase

      return 36; // per "Programming ODBC for SQLServer" Appendix A
   }


   /**
    * What's the maximum length of a single row?
    *