cpl_odbc.cpp

用于读取TAB、MIF、SHP文件的类

        m_panColValueLengths = NULL;
    }

}

/************************************************************************/
/*                             GetColumns()                             */
/************************************************************************/

/**
 * Fetch column definitions for a table.
 *
 * The SQLColumn() method is used to fetch the definitions for the columns
 * of a table (or other queriable object such as a view).  The column
 * definitions are digested and used to populate the CPLODBCStatement
 * column definitions essentially as if a "SELECT * FROM tablename" had
 * been done; however, no resultset will be available.
 *
 * @param pszTable the name of the table to query information on.  This
 * should not be empty.
 *
 * @param pszCatalog the catalog to find the table in, use NULL (the
 * default) if no catalog is available. 
 *
 * @param pszSchema the schema to find the table in, use NULL (the
 * default) if no schema is available. 
 *
 * @return TRUE on success or FALSE on failure. 
 */

int CPLODBCStatement::GetColumns( const char *pszTable, 
                                  const char *pszCatalog,
                                  const char *pszSchema )

{
#ifdef notdef
    if( pszCatalog == NULL )
        pszCatalog = "";
    if( pszSchema == NULL )
        pszSchema = "";
#endif
/* -------------------------------------------------------------------- */
/*      Fetch columns resultset for this table.                         */
/* -------------------------------------------------------------------- */
    if( Failed( SQLColumns( m_hStmt, 
                            (SQLCHAR *) pszCatalog, SQL_NTS,
                            (SQLCHAR *) pszSchema, SQL_NTS,
                            (SQLCHAR *) pszTable, SQL_NTS,
                            (SQLCHAR *) NULL /* "" */, SQL_NTS ) ) )
        return FALSE;

/* -------------------------------------------------------------------- */
/*      Allocate per column information.                                */
/* -------------------------------------------------------------------- */
#ifdef notdef
    // SQLRowCount() is too unreliable (with unixodbc on AIX for instance)
    // so we now avoid it.
    SQLINTEGER nResultCount=0;

    if( Failed(SQLRowCount( m_hStmt, &nResultCount ) ) )
        nResultCount = 0;

    if( nResultCount < 1 )
        m_nColCount = 500; // Hopefully lots.
    else
        m_nColCount = nResultCount;
#endif

    m_nColCount = 500;
    
    m_papszColNames = (char **) CPLCalloc(sizeof(char *),(m_nColCount+1));
    m_papszColValues = (char **) CPLCalloc(sizeof(char *),(m_nColCount+1));

    m_panColType = (short *) CPLCalloc(sizeof(short),m_nColCount);
    m_papszColTypeNames = (char **) CPLCalloc(sizeof(char *),(m_nColCount+1));
    m_panColSize = (_SQLULEN *) CPLCalloc(sizeof(_SQLULEN),m_nColCount);
    m_panColPrecision = (short *) CPLCalloc(sizeof(short),m_nColCount);
    m_panColNullable = (short *) CPLCalloc(sizeof(short),m_nColCount);

/* -------------------------------------------------------------------- */
/*      Establish columns to use for key information.                   */
/* -------------------------------------------------------------------- */
    SQLUSMALLINT iCol;

    for( iCol = 0; iCol < m_nColCount; iCol++ )
    {
        char szWrkData[8193];
        _SQLLEN cbDataLen;

        if( Failed( SQLFetch( m_hStmt ) ) )
        {
            m_nColCount = iCol;
            break;
        }

        szWrkData[0] = '\0';

        SQLGetData( m_hStmt, SQLColumns_COLUMN_NAME, SQL_C_CHAR,
                    szWrkData, sizeof(szWrkData)-1, &cbDataLen );
        m_papszColNames[iCol] = CPLStrdup(szWrkData);

        SQLGetData( m_hStmt, SQLColumns_DATA_TYPE, SQL_C_CHAR,
                    szWrkData, sizeof(szWrkData)-1, &cbDataLen );
        m_panColType[iCol] = (short) atoi(szWrkData);

        SQLGetData( m_hStmt, SQLColumns_TYPE_NAME, SQL_C_CHAR,
                    szWrkData, sizeof(szWrkData)-1, &cbDataLen );
        m_papszColTypeNames[iCol] = CPLStrdup(szWrkData);

        SQLGetData( m_hStmt, SQLColumns_COLUMN_SIZE, SQL_C_CHAR,
                    szWrkData, sizeof(szWrkData)-1, &cbDataLen );
        m_panColSize[iCol] = atoi(szWrkData);

        SQLGetData( m_hStmt, SQLColumns_DECIMAL_DIGITS, SQL_C_CHAR,
                    szWrkData, sizeof(szWrkData)-1, &cbDataLen );
        m_panColPrecision[iCol] = (short) atoi(szWrkData);

        SQLGetData( m_hStmt, SQLColumns_NULLABLE, SQL_C_CHAR,
                    szWrkData, sizeof(szWrkData)-1, &cbDataLen );
        m_panColNullable[iCol] = atoi(szWrkData) == SQL_NULLABLE;
    }

    return TRUE;
}

/************************************************************************/
/*                           GetPrimaryKeys()                           */
/************************************************************************/

/**
 * Fetch primary keys for a table.
 *
 * The SQLPrimaryKeys() function is used to fetch a list of fields
 * forming the primary key.  The result is returned as a result set matching
 * the SQLPrimaryKeys() function result set.  The 4th column in the result
 * set is the column name of the key, and if the result set contains only
 * one record then that single field will be the complete primary key.
 *
 * @param pszTable the name of the table to query information on.  This
 * should not be empty.
 *
 * @param pszCatalog the catalog to find the table in, use NULL (the
 * default) if no catalog is available. 
 *
 * @param pszSchema the schema to find the table in, use NULL (the
 * default) if no schema is available. 
 *
 * @return TRUE on success or FALSE on failure. 
 */

int CPLODBCStatement::GetPrimaryKeys( const char *pszTable, 
                                      const char *pszCatalog,
                                      const char *pszSchema )

{
    if( pszCatalog == NULL )
        pszCatalog = "";
    if( pszSchema == NULL )
        pszSchema = "";

/* -------------------------------------------------------------------- */
/*      Fetch columns resultset for this table.                         */
/* -------------------------------------------------------------------- */
    if( Failed( SQLPrimaryKeys( m_hStmt, 
                                (SQLCHAR *) pszCatalog, SQL_NTS,
                                (SQLCHAR *) pszSchema, SQL_NTS,
                                (SQLCHAR *) pszTable, SQL_NTS ) ) )
        return FALSE;
    else
        return CollectResultsInfo();
}

/************************************************************************/
/*                             GetTables()                              */
/************************************************************************/

/**
 * Fetch tables in database.
 *
 * The SQLTables() function is used to fetch a list tables in the
 * database.    The result is returned as a result set matching
 * the SQLTables() function result set.  The 3rd column in the result
 * set is the table name.  Only tables of type "TABLE" are returned. 
 *
 * @param pszCatalog the catalog to find the table in, use NULL (the
 * default) if no catalog is available. 
 *
 * @param pszSchema the schema to find the table in, use NULL (the
 * default) if no schema is available. 
 *
 * @return TRUE on success or FALSE on failure. 
 */

int CPLODBCStatement::GetTables( const char *pszCatalog,
                                 const char *pszSchema )

{
    CPLDebug( "ODBC", "CatalogNameL: %s\nSchema name: %s\n",
                pszCatalog, pszSchema );

/* -------------------------------------------------------------------- */
/*      Fetch columns resultset for this table.                         */
/* -------------------------------------------------------------------- */
    if( Failed( SQLTables( m_hStmt, 
                           (SQLCHAR *) pszCatalog, SQL_NTS,
                           (SQLCHAR *) pszSchema, SQL_NTS,
                           (SQLCHAR *) NULL, SQL_NTS,
                           (SQLCHAR *) "'TABLE','VIEW'", SQL_NTS ) ) )
        return FALSE;
    else
        return CollectResultsInfo();
}

/************************************************************************/
/*                             DumpResult()                             */
/************************************************************************/

/**
 * Dump resultset to file.
 *
 * The contents of the current resultset are dumped in a simply formatted
 * form to the provided file.  If requested, the schema definition will
 * be written first. 
 *
 * @param fp the file to write to.  stdout or stderr are acceptable. 
 *
 * @param bShowSchema TRUE to force writing schema information for the rowset
 * before the rowset data itself.  Default is FALSE.
 */

void CPLODBCStatement::DumpResult( FILE *fp, int bShowSchema )

{
    int iCol;

/* -------------------------------------------------------------------- */
/*      Display schema                                                  */
/* -------------------------------------------------------------------- */
    if( bShowSchema )
    {
        fprintf( fp, "Column Definitions:\n" );
        for( iCol = 0; iCol < GetColCount(); iCol++ )
        {
            fprintf( fp, " %2d: %-24s ", iCol, GetColName(iCol) );
            if( GetColPrecision(iCol) > 0 
                && GetColPrecision(iCol) != GetColSize(iCol) )
                fprintf( fp, " Size:%3d.%d", 
                         GetColSize(iCol), GetColPrecision(iCol) );
            else
                fprintf( fp, " Size:%5d", GetColSize(iCol) );

            CPLString osType = GetTypeName( GetColType(iCol) );
            fprintf( fp, " Type:%s", osType.c_str() );
            if( GetColNullable(iCol) )
                fprintf( fp, " NULLABLE" );
            fprintf( fp, "\n" );
        }
        fprintf( fp, "\n" );
    }

/* -------------------------------------------------------------------- */
/*      Display results                                                 */
/* -------------------------------------------------------------------- */
    int iRecord = 0;
    while( Fetch() )
    {
        fprintf( fp, "Record %d\n", iRecord++ );
        
        for( iCol = 0; iCol < GetColCount(); iCol++ )
        {
            fprintf( fp, "  %s: %s\n", GetColName(iCol), GetColData(iCol) );
        }
    }
}

/************************************************************************/
/*                            GetTypeName()                             */
/************************************************************************/

/**
 * Get name for SQL column type.
 *
 * Returns a string name for the indicated type code (as returned
 * from CPLODBCStatement::GetColType()).
 *
 * @param nTypeCode the SQL_ code, such as SQL_CHAR.
 *
 * @return internal string, "UNKNOWN" if code not recognised. 
 */

CPLString CPLODBCStatement::GetTypeName( int nTypeCode )

{
    switch( nTypeCode )
    {
      case SQL_CHAR:
        return "CHAR";
        
      case SQL_NUMERIC:
        return "NUMERIC";
        
      case SQL_DECIMAL:
        return "DECIMAL";
        
      case SQL_INTEGER:
        return "INTEGER";
        
      case SQL_SMALLINT:
        return "SMALLINT";

        
      case SQL_FLOAT:
        return "FLOAT";
        
      case SQL_REAL:
        return "REAL";

      case SQL_DOUBLE:
        return "DOUBLE";
        
      case SQL_DATETIME:
        return "DATETIME";

      case SQL_VARCHAR:
        return "VARCHAR";

      case SQL_TYPE_DATE:
        return "DATE";

      case SQL_TYPE_TIME:
        return "TIME";
        
      case SQL_TYPE_TIMESTAMP:
        return "TIMESTAMP";

      default:
        CPLString osResult;
        osResult.Printf( "UNKNOWN:%d", nTypeCode );
        return osResult;
    }
}

/************************************************************************/
/*                            GetTypeMapping()                          */
/************************************************************************/

/**
 * Get appropriate C data type for SQL column type.
 *
 * Returns a C data type code, corresponding to the indicated SQL data
 * type code (as returned from CPLODBCStatement::GetColType()).
 *
 * @param nTypeCode the SQL_ code, such as SQL_CHAR.
 *
 * @return data type code. The valid code is always returned. If SQL
 * code is not recognised, SQL_C_BINARY will be returned.
 */

SQLSMALLINT CPLODBCStatement::GetTypeMapping( SQLSMALLINT nTypeCode )

{
    switch( nTypeCode )
    {
        case SQL_CHAR:
        case SQL_VARCHAR:
        case SQL_LONGVARCHAR:
        case SQL_WCHAR:
        case SQL_WVARCHAR:
        case SQL_WLONGVARCHAR:
            return SQL_C_CHAR;

        case SQL_DECIMAL:
        case SQL_NUMERIC:
            return SQL_C_NUMERIC;

        case SQL_SMALLINT:
            return SQL_C_SSHORT;

        case SQL_INTEGER:
            return SQL_C_SLONG;

        case SQL_REAL:
            return SQL_C_FLOAT;

        case SQL_FLOAT:
        case SQL_DOUBLE:
            return SQL_C_DOUBLE;

        case SQL_BIT:
        case SQL_TINYINT:
        case SQL_BIGINT:
        case SQL_TYPE_DATE:
        case SQL_TYPE_TIME:
        case SQL_TYPE_TIMESTAMP:
/*        case SQL_TYPE_UTCDATETIME:
        case SQL_TYPE_UTCTIME:*/
        case SQL_INTERVAL_MONTH:
        case SQL_INTERVAL_YEAR:
        case SQL_INTERVAL_YEAR_TO_MONTH:
        case SQL_INTERVAL_DAY:
        case SQL_INTERVAL_HOUR:
        case SQL_INTERVAL_MINUTE:
        case SQL_INTERVAL_SECOND:
        case SQL_INTERVAL_DAY_TO_HOUR:
        case SQL_INTERVAL_DAY_TO_MINUTE:
        case SQL_INTERVAL_DAY_TO_SECOND:
        case SQL_INTERVAL_HOUR_TO_MINUTE:
        case SQL_INTERVAL_HOUR_TO_SECOND:
        case SQL_INTERVAL_MINUTE_TO_SECOND:
        case SQL_GUID:
            return SQL_C_CHAR;

        case SQL_BINARY:
        case SQL_VARBINARY:
        case SQL_LONGVARBINARY:
            return SQL_C_BINARY;

        default:
            return SQL_C_CHAR;
    }
}

#endif /* #ifndef WIN32CE */