databasemetadata.java

SSD9 练习9

	Vector Tuples = new Vector();

	while (RS.next()) {
	    byte[][] RowVal = new byte[1][];
	    RowVal[0] = RS.getBytes(1);
	    Tuples.addElement(RowVal);
	}
		  
	return new ResultSet(Fields, Tuples, _Conn);
    }
  
    /**
     * Get the table types available in this database.  The results
     * are ordered by table type.
     *
     * <P>The table type is:
     *  <OL>
     *    <LI><B>TABLE_TYPE</B> String => table type.  Typical types are "TABLE",
     *                    "VIEW", "SYSTEM TABLE", "GLOBAL TEMPORARY",
     *                    "LOCAL TEMPORARY", "ALIAS", "SYNONYM".
     *  </OL>
     *
     * @return ResultSet each row has a single String column that is a
     * table type
     */

    public java.sql.ResultSet getTableTypes() throws java.sql.SQLException
    {
	Vector Tuples = new Vector();
	Field[] Fields = new Field[1];
	Fields[0] = new Field("", "TABLE_TYPE", Types.VARCHAR, 5);
	byte[][] TType = new byte[1][];
	TType[0] = _Table_As_Bytes;
	Tuples.addElement(TType);

	return new ResultSet(Fields, Tuples, _Conn);
    }
  
    /**
     * Get a description of table columns available in a catalog.
     *
     * <P>Only column descriptions matching the catalog, schema, table
     * and column name criteria are returned.  They are ordered by
     * TABLE_SCHEM, TABLE_NAME and ORDINAL_POSITION.
     *
     * <P>Each 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>COLUMN_NAME</B> String => column name
     *    <LI><B>DATA_TYPE</B> short => SQL type from java.sql.Types
     *    <LI><B>TYPE_NAME</B> String => Data source dependent type name
     *    <LI><B>COLUMN_SIZE</B> int => column size.  For char or date
     *        types this is the maximum number of characters, for numeric or
     *        decimal types this is precision.
     *    <LI><B>BUFFER_LENGTH</B> is not used.
     *    <LI><B>DECIMAL_DIGITS</B> int => the number of fractional digits
     *    <LI><B>NUM_PREC_RADIX</B> int => Radix (typically either 10 or 2)
     *    <LI><B>NULLABLE</B> int => is NULL allowed?
     *      <UL>
     *      <LI> columnNoNulls - might not allow NULL values
     *      <LI> columnNullable - definitely allows NULL values
     *      <LI> columnNullableUnknown - nullability unknown
     *      </UL>
     *    <LI><B>REMARKS</B> String => comment describing column (may be null)
     *    <LI><B>COLUMN_DEF</B> String => default value (may be null)
     *    <LI><B>SQL_DATA_TYPE</B> int => unused
     *    <LI><B>SQL_DATETIME_SUB</B> int => unused
     *    <LI><B>CHAR_OCTET_LENGTH</B> int => for char types the
     *       maximum number of bytes in the column
     *    <LI><B>ORDINAL_POSITION</B> int => index of column in table
     *      (starting at 1)
     *    <LI><B>IS_NULLABLE</B> String => "NO" means column definitely
     *      does not allow NULL values; "YES" means the column might
     *      allow NULL values.  An empty string means nobody knows.
     *  </OL>
     *
     * @param catalog a catalog name; "" retrieves those without a catalog
     * @param schemaPattern a schema name pattern; "" retrieves those
     * without a schema
     * @param tableNamePattern a table name pattern
     * @param columnNamePattern a column name pattern
     * @return ResultSet each row is a column description
     * @see #getSearchStringEscape
     */

    public java.sql.ResultSet getColumns(String Catalog, String SchemaPattern,
					 String TableName, 
					 String ColumnNamePattern)
	throws java.sql.SQLException
    {
	String DB_Sub = "";

	if (ColumnNamePattern == null) {
	    ColumnNamePattern = "%";
	}

	if (Catalog != null) {
	    if (!Catalog.equals("")) {
		DB_Sub = " FROM " + Catalog;
	    }
	}
	else {
	    DB_Sub = " FROM " + _Database;
	}
		
	Vector TableNameList = new Vector();
		
	int tablename_length = 0;
		
	if (TableName == null) {
	    // Select from all tables
	    java.sql.ResultSet Tables = getTables(Catalog, SchemaPattern, "%", new String[0]);
			
	    while (Tables.next()) {
		String TN = Tables.getString("TABLE_NAME");
				
		TableNameList.addElement(TN);
				
		if (TN.length() > tablename_length) {
		    tablename_length = TN.length();
		}
	    }
	    Tables.close();
	}
	else {
	    TableNameList.addElement(TableName);
	    tablename_length = TableName.length();
	}
			
	int catalog_length = 0;
			
	if (Catalog != null) {
	    catalog_length = Catalog.length();
	}
			
	java.util.Enumeration TableNames = TableNameList.elements();
		
	Field[] Fields = new Field[18];
		
	Fields[0]  = new Field("", "TABLE_CAT"        , Types.CHAR, 
			       catalog_length);
	Fields[1]  = new Field("", "TABLE_SCHEM"      , Types.CHAR,     0);
	Fields[2]  = new Field("", "TABLE_NAME"       , Types.CHAR,
			       tablename_length);
	Fields[3]  = new Field("", "COLUMN_NAME"      , Types.CHAR,     32);
	Fields[4]  = new Field("", "DATA_TYPE"        , Types.SMALLINT, 5);
	Fields[5]  = new Field("", "TYPE_NAME"        , Types.CHAR,     16);
	Fields[6]  = new Field("", "COLUMN_SIZE"      , Types.INTEGER,   
			       Integer.toString(Integer.MAX_VALUE).length());
	Fields[7]  = new Field("", "BUFFER_LENGTH"    , Types.INTEGER,  10);
	Fields[8]  = new Field("", "DECIMAL_DIGITS"   , Types.INTEGER,  10);
	Fields[9]  = new Field("", "NUM_PREC_RADIX"   , Types.INTEGER,  10);
	Fields[10] = new Field("", "NULLABLE"         , Types.INTEGER,  10);
	Fields[11] = new Field("", "REMARKS"          , Types.CHAR,     0);
	Fields[12] = new Field("", "COLUMN_DEF"       , Types.CHAR,     0);
	Fields[13] = new Field("", "SQL_DATA_TYPE"    , Types.INTEGER,  10);
	Fields[14] = new Field("", "SQL_DATETIME_SUB",  Types.INTEGER,  10);
	Fields[15] = new Field("", "CHAR_OCTET_LENGTH", Types.INTEGER,      
			       Integer.toString(Integer.MAX_VALUE).length());
	Fields[16] = new Field("", "ORDINAL_POSITION" , Types.INTEGER,  10);
	Fields[17] = new Field("", "IS_NULLABLE"      , Types.CHAR,     3);

	Vector Tuples = new Vector();
		
	while (TableNames.hasMoreElements()) {
				
	    String TableNamePattern = (String)TableNames.nextElement();
			
	    org.gjt.mm.mysql.ResultSet RS = _Conn.execSQL(
							  "show columns from " + 
							  TableNamePattern + DB_Sub + " like '" 
							  + ColumnNamePattern + "'", -1);
	    RS.setConnection(_Conn);

	    java.sql.ResultSetMetaData RSMD = RS.getMetaData();
			
	    int ord_pos = 1;

	    /*
	     * Fix up Catalog and TableName
	     */
			 
	    if (Catalog == null) {
		Catalog = "";
	    }
    
	    if (TableName == null) {
		TableName = "";
	    }
    
	    while (RS.next()) {
		byte[][] RowVal = new byte[18][];

		RowVal[0] = Catalog.getBytes();   // TABLE_CAT
		RowVal[1] = new byte[0];        // TABLE_SCHEM (No schemas in MySQL)
			  
		RowVal[2] = TableName.getBytes(); // TABLE_NAME
		RowVal[3] = RS.getBytes("Field");
			  
		String TypeInfo = RS.getString("Type");
		if (Driver.debug) {
		    System.out.println("Type: " + TypeInfo);
		}
		String MysqlType = "";
			  
		if (TypeInfo.indexOf("(") != -1) {
		    MysqlType = TypeInfo.substring(0, TypeInfo.indexOf("("));
		}
		else {
		    MysqlType = TypeInfo;
		}

		/* 
		 * Convert to XOPEN (thanks JK)
		 */

		RowVal[4] = Integer.toString(MysqlDefs.mysqlToJavaType(MysqlType)).getBytes(); // DATA_TYPE (jdbc)

		RowVal[5] = MysqlType.getBytes(); // TYPE_NAME (native)

		// Figure Out the Size

		if (TypeInfo != null) {
		    if (TypeInfo.indexOf("enum") != -1) {
			String Temp = TypeInfo.substring(TypeInfo.indexOf("("), TypeInfo.indexOf(")"));
					
			java.util.StringTokenizer ST = new java.util.StringTokenizer(Temp, ",");
					
			int max_length = 0;
					
			while (ST.hasMoreTokens()) {
			    max_length = Math.max(max_length, (ST.nextToken().length() - 2));
			}
			RowVal[6] = Integer.toString(max_length).getBytes();
			RowVal[8] = new byte[] {(byte)'0'};
		    }
		    else if (TypeInfo.indexOf(",") != -1) {
			// Numeric with decimals
			String Size = TypeInfo.substring((TypeInfo.indexOf("(") + 1),
							 (TypeInfo.indexOf(",")));
			String Decimals = TypeInfo.substring((TypeInfo.indexOf(",") + 1),
							     (TypeInfo.indexOf(")")));
			RowVal[6] = Size.getBytes();
			RowVal[8] = Decimals.getBytes();
		    }
		    else {
			String Size = "0";

			/* If the size is specified with the DDL, use that */

						
			if (TypeInfo.indexOf("(") != -1) {
			    Size = TypeInfo.substring((TypeInfo.indexOf("(") + 1),
						      (TypeInfo.indexOf(")")));
			}
			/* Otherwise resort to defaults */
			else if (TypeInfo.toLowerCase().equals("tinyint")) {
			    Size = "1";
			}
			else if (TypeInfo.toLowerCase().equals("smallint")) {
			    Size = "6";
			}
			else if (TypeInfo.toLowerCase().equals("mediumint")) {
			    Size = "6";
			}
			else if (TypeInfo.toLowerCase().equals("int")) {
			    Size = "11";
			}
			else if (TypeInfo.toLowerCase().equals("integer")) {
			    Size = "11";
			}
			else if (TypeInfo.toLowerCase().equals("bigint")) {
			    Size = "25";
			}
			else if (TypeInfo.toLowerCase().equals("int24")) {
			    Size = "25";
			}
			else if (TypeInfo.toLowerCase().equals("real")) {
			    Size = "12";
			}
			else if (TypeInfo.toLowerCase().equals("float")) {
			    Size = "12";
			}
			else if (TypeInfo.toLowerCase().equals("decimal")) {
			    Size = "12";
			}
			else if (TypeInfo.toLowerCase().equals("numeric")) {
			    Size = "12";
			}
			else if (TypeInfo.toLowerCase().equals("double")) {
			    Size = "22";
			}
			else if (TypeInfo.toLowerCase().equals("char")) {
			    Size = "1";
			}
			else if (TypeInfo.toLowerCase().equals("varchar")) {
			    Size = "255";
			}
			else if (TypeInfo.toLowerCase().equals("date")) {
			    Size = "10";
			}
			else if (TypeInfo.toLowerCase().equals("time")) {
			    Size = "8";
			}
			else if (TypeInfo.toLowerCase().equals("timestamp")) {
			    Size = "19";
			}
			else if (TypeInfo.toLowerCase().equals("datetime")) {
			    Size = "19";
			}
			else if (TypeInfo.toLowerCase().equals("tinyblob")) {
			    Size = "255";
			}
			else if (TypeInfo.toLowerCase().equals("blob")) {
			    Size = Integer.toString(Math.min(65535, MysqlIO.getMaxBuf()));
			}
			else if (TypeInfo.toLowerCase().equals("mediumblob")) {
			    Size = Integer.toString(Math.min(16277215, MysqlIO.getMaxBuf()));
			}
			else if (TypeInfo.toLowerCase().equals("longblob")) {
			    Size = (Integer.toString(MysqlIO.getMaxBuf()).compareTo("2147483657") < 0 ? Integer.toString(MysqlIO.getMaxBuf()) : "2147483657");
			}
			else if (TypeInfo.toLowerCase().equals("tinytext")) {
			    Size = "255";
			}
			else if (TypeInfo.toLowerCase().equals("text")) {
			    Size = "65535";
			}
			else if (TypeInfo.toLowerCase().equals("mediumtext")) {
			    Size = Integer.toString(Math.min(16277215, MysqlIO.getMaxBuf()));
			}
			else if (TypeInfo.toLowerCase().equals("enum")) {
			    Size = "255";
			}
			else if (TypeInfo.toLowerCase().equals("set")) {
			    Size = "255";
			}

			RowVal[6] = Size.getBytes();
			RowVal[8] = new byte[] {(byte)'0'};
		    }
		}
		else {                    
		    RowVal[8] = new byte[] {(byte)'0'};
		    RowVal[6] = new byte[] {(byte)'0'};
		}

		RowVal[7] = Integer.toString(MysqlIO.MAXBUF).getBytes(); // BUFFER_LENGTH
		RowVal[9] = new byte[] {(byte)'1',(byte)'0'}; // NUM_PREC_RADIX (is this right for char?)

		String Nullable = RS.getString("Null");

		// Nullable?

		if (Nullable != null) {
		    if (Nullable.equals("YES")) {
			RowVal[10] = Integer.toString(columnNullable).getBytes();
			RowVal[17] = new String("YES").getBytes(); // IS_NULLABLE
		    }
		    else {
			RowVal[10] = Integer.toString(columnNoNulls).getBytes();
			RowVal[17] = new String("NO").getBytes();
		    }
		}
		else {
		    RowVal[10] = Integer.toString(columnNoNulls).getBytes();
		    RowVal[17] = new String("NO").getBytes();
		}

		RowVal[11] = new byte[0]; // REMARK
			  
		// COLUMN_DEF
		byte[] Default = RS.getBytes("Default");

		if (Default != null) {
		    RowVal[12] = Default;
		}
		else {
		    RowVal[12] = new byte[0];
		}

		RowVal[13] = new byte[] {(byte)'0'};  // SQL_DATA_TYPE
		RowVal[14] = new byte[] {(byte)'0'};       // SQL_DATE_TIME_SUB
		RowVal[15] = RowVal[6];       // CHAR_OCTET_LENGTH
		RowVal[16] = Integer.toString(ord_pos++).getBytes();  // ORDINAL_POSITION
			 
		Tuples.addElement(RowVal);
	    }
	    RS.close();
	}
    
	ResultSet Results = new ResultSet(Fields, Tuples, _Conn);
	return Results;
    }

    /**
     * Get a description of the access rights for a table's columns.
     *
     * <P>Only privileges matching the column name criteria are
     * returned.  They are ordered by COLUMN_NAME and PRIVILEGE.
     *
     * <P>Each privilige 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>COLUMN_NAME</B> String => column name
     *    <LI><B>GRANTOR</B> => grantor of access (may be null)
     *    <LI><B>GRANTEE</B> String => grantee of access
     *    <LI><B>PRIVILEGE</B> String => name of access (SELECT,
     *      INSERT, UPDATE, REFRENCES, ...)
     *    <LI><B>IS_GRANTABLE</B> String => "YES" if grantee is permitted
     *      to grant to others; "NO" if not; null if unknown
     *  </OL>
     *
     * @param catalog a catalog name; "" retrieves those without a catalog
     * @param schema a schema name; "" retrieves those without a schema
     * @param table a table name
     * @param columnNamePattern a column name pattern
     * @return ResultSet each row is a column privilege description
     * @see #getSearchStringEscape
     */

    public java.sql.ResultSet getColumnPrivileges(String catalog, String schema,
						  String table, String columnNamePattern) throws java.sql.SQLException 
    {
	Field[] Fields = new Field[8];
    
	Fields[0]  = new Field("", "TABLE_CAT",    Types.CHAR,     1);
	Fields[1]  = new Field("", "TABLE_SCHEM",  Types.CHAR,     1);
	Fields[2]  = new Field("", "TABLE_NAME",   Types.CHAR,     1);
	Fields[3]  = new Field("", "COLUMN_NAME",  Types.CHAR,     1);
	Fields[4]  = new Field("", "GRANTOR",      Types.CHAR,     1);
	Fields[5]  = new Field("", "GRANTEE",      Types.CHAR,     1);
	Fields[6]  = new Field("", "PRIVILEGE",    Types.CHAR,     1); 
	Fields[7]  = new Field("", "IS_GRANTABLE", Types.CHAR,     1);
    
	return new ResultSet(Fields, new Vector(), _Conn);
    }

    /**
     * Get a description of the access rights for each table available
     * in a catalog.
     *
     * <P>Only privileges matching the schema and table name
     * criteria are returned.  They are ordered by TABLE_SCHEM,
     * TABLE_NAME, and PRIVILEGE.
     *
     * <P>Each privilige 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>COLUMN_NAME</B> String => column name
     *    <LI><B>GRANTOR</B> => grantor of access (may be null)
     *    <LI><B>GRANTEE</B> String => grantee of access
     *    <LI><B>PRIVILEGE</B> String => name of access (SELECT,
     *      INSERT, UPDATE, REFRENCES, ...)
     *    <LI><B>IS_GRANTABLE</B> String => "YES" if grantee is permitted
     *      to grant to others; "NO" if not; null if unknown
     *  </OL>
     *
     * @param catalog a catalog name; "" retrieves those without a catalog
     * @param schemaPattern a schema name pattern; "" retrieves those
     * without a schema
     * @param tableNamePattern a table name pattern
     * @return ResultSet each row is a table privilege description
     * @see #getSearchStringEscape
     */

    public java.sql.ResultSet getTablePrivileges(S