databasemetadata.java

Java写的TDS协议(JDBC/ODBC)实现

     */
    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 sysnameLength; // per "Programming ODBC for SQLServer" Appendix A
        // 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 sysnameLength; // per "Programming ODBC for SQLServer" Appendix A
        // per "Programming ODBC for SQLServer" Appendix A
    }

    /**
     *  What's the maximum length of a single row?
     *
     *@return                   max row size in bytes
     *@exception  SQLException  if a database-access error occurs.
     */
    public int getMaxRowSize() 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 1962;
    }

    /**
     *  What's the maximum length allowed for a schema name?
     *
     *@return                   max name length in bytes
     *@exception  SQLException  if a database-access error occurs.
     */
    public int getMaxSchemaNameLength() throws SQLException
    {
        return sysnameLength;
    }

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

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

    /**
     *  How many active statements can we have open at one time to this
     *  database?
     *
     *@return                   the maximum
     *@exception  SQLException  if a database-access error occurs.
     */
    public int getMaxStatements() throws SQLException
    {
        return 0;
    }

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

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

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

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

    /**
     *  What's the maximum length of a user name?
     *
     *@return                   max name length in bytes
     *@exception  SQLException  if a database-access error occurs.
     */
    public int getMaxUserNameLength() throws SQLException
    {
        // XXX need to find out if this is still true for SYBASE
        return sysnameLength;
    }

    /**
     *  Get a comma separated list of math functions.
     *
     *@return                   the list
     *@exception  SQLException  if a database-access error occurs.
     */
    public String getNumericFunctions() throws SQLException
    {
        // @todo Implement (a)%(b) for MOD(a,b)
        // XXX need to find out if this is still true for SYBASE
        return "ABS,ACOS,ASIN,ATAN,ATAN2,CEILING,COS,COT,DEGREES,EXP,FLOOR,LOG,LOG10,PI,POWER,RADIANS,RAND,ROUND,SIGN,SIN,SQRT,TAN";
    }

    /**
     *  Get a description of a table's primary key columns. They are ordered by
     *  COLUMN_NAME. <P>
     *
     *  Each primary key 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>KEY_SEQ</B> short =>sequence number within primary key
     *    <LI> <B>PK_NAME</B> String =>primary key name (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
     *@return                   ResultSet - each row is a primary key column
     *      description
     *@exception  SQLException  if a database-access error occurs.
     */
    public java.sql.ResultSet getPrimaryKeys(
        String catalog,
        String schema,
        String table)
        throws SQLException
    {
        String query = "exec sp_pkeys ?, ?, ?";
        if( catalog != null )
            query = "exec "+catalog+"..sp_pkeys ?, ?, ?";

        CallableStatement s = connection.prepareCall(query);
        s.setString(1, table);
        s.setString(2, schema);
        s.setString(3, catalog);

        TdsResultSet rs = (TdsResultSet)s.executeQuery();
        Columns col = rs.getContext().getColumnInfo();

        col.setName(1, "TABLE_CAT");
        col.setLabel(1, "TABLE_CAT");
        col.setName(2, "TABLE_SCHEM");
        col.setLabel(2, "TABLE_SCHEM");

        return rs;
    }

    /**
     *  Get a description of a catalog's stored procedure parameters and result
     *  columns. <P>
     *
     *  Only descriptions matching the schema, procedure and parameter name
     *  criteria are returned. They are ordered by PROCEDURE_SCHEM and
     *  PROCEDURE_NAME. Within this, the return value, if any, is first. Next
     *  are the parameter descriptions in call order. The column descriptions
     *  follow in column number order. <P>
     *
     *  Each row in the ResultSet is a parameter description or column
     *  description with the following fields:
     *  <OL>
     *    <LI> <B>PROCEDURE_CAT</B> String =>procedure catalog (may be null)
     *
     *    <LI> <B>PROCEDURE_SCHEM</B> String =>procedure schema (may be null)
     *
     *    <LI> <B>PROCEDURE_NAME</B> String =>procedure name
     *    <LI> <B>COLUMN_NAME</B> String =>column/parameter name
     *    <LI> <B>COLUMN_TYPE</B> Short =>kind of column/parameter:
     *    <UL>
     *      <LI> procedureColumnUnknown - nobody knows
     *      <LI> procedureColumnIn - IN parameter
     *      <LI> procedureColumnInOut - INOUT parameter
     *      <LI> procedureColumnOut - OUT parameter
     *      <LI> procedureColumnReturn - procedure return value
     *      <LI> procedureColumnResult - result column in ResultSet
     *    </UL>
     *
     *    <LI> <B>DATA_TYPE</B> short =>SQL type from java.sql.Types
     *    <LI> <B>TYPE_NAME</B> String =>SQL type name
     *    <LI> <B>PRECISION</B> int =>precision
     *    <LI> <B>LENGTH</B> int =>length in bytes of data
     *    <LI> <B>SCALE</B> short =>scale
     *    <LI> <B>RADIX</B> short =>radix
     *    <LI> <B>NULLABLE</B> short =>can it contain NULL?
     *    <UL>
     *      <LI> procedureNoNulls - does not allow NULL values
     *      <LI> procedureNullable - allows NULL values
     *      <LI> procedureNullableUnknown - nullability unknown
     *    </UL>
     *
     *    <LI> <B>REMARKS</B> String =>comment describing parameter/column
     *  </OL>
     *  <P>
     *
     *  <B>Note:</B> Some databases may not return the column descriptions for a
     *  procedure. Additional columns beyond REMARKS can be defined by the
     *  database.
     *
     *@param  catalog               a catalog name; "" retrieves those without a
     *      catalog; null means drop catalog name from the selection criteria
     *@param  schemaPattern         a schema name pattern; "" retrieves those
     *      without a schema
     *@param  procedureNamePattern  a procedure name pattern
     *@param  columnNamePattern     a column name pattern
     *@return                       ResultSet - each row is a stored procedure
     *      parameter or column description
     *@exception  SQLException      if a database-access error occurs.
     *@see                          #getSearchStringEscape
     */
    public java.sql.ResultSet getProcedureColumns(
            String catalog,
            String schemaPattern,
            String procedureNamePattern,
            String columnNamePattern )
             throws SQLException
    {
        String query = "exec sp_sproc_columns ?, ?, ?, ?, 3";
        if( catalog != null )
            query = "exec "+catalog+"..sp_sproc_columns ?, ?, ?, ?, 3";

        CallableStatement s = connection.prepareCall(query);
        s.setString(1, procedureNamePattern);
        s.setString(2, schemaPattern);
        s.setString(3, catalog);
        s.setString(4, columnNamePattern);

        TdsResultSet rs = (TdsResultSet)s.executeQuery();
        Columns col = rs.getContext().getColumnInfo();

        col.setName(1, "PROCEDURE_CAT");
        col.setLabel(1, "PROCEDURE_CAT");
        col.setName(2, "PROCEDURE_SCHEM");
        col.setLabel(2, "PROCEDURE_SCHEM");

        return rs;
    }

    /**
     *  Get a description of stored procedures available in a catalog. <P>
     *
     *  Only procedure descriptions matching the schema and procedure name
     *  criteria are returned. They are ordered by PROCEDURE_SCHEM, and
     *  PROCEDURE_NAME. <P>
     *
     *  Each procedure description has the the following columns:
     *  <OL>
     *    <LI> <B>PROCEDURE_CAT</B> String =>procedure catalog (may be null)
     *
     *    <LI> <B>PROCEDURE_SCHEM</B> String =>procedure schema (may be null)