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MapObjects AddRelate的使用信息和建议
在mo中连接外部表来增强程序信息量在一些应用中还是很有用的,大家看看下面的东东
Applies to: MapObjects 2.0 The following things have been found to be important issues when using the AddRelate method in MapObjects 2.0. Although this list is not intended to be exhaustive, nor is it guaranteed to work if adhered to in every case, you are welcome to try these suggestions if you are experiencing problems with AddRelate. Relates to MSAccess 2000 *.MDB tables. MapObjects 2.0 requires DAO 3.5; MapObjects 1.2 requires DAO 3.0. When relating to SQL Server, the relate field must not be of type nVarChar; use type VarChar. When relating to a Paradox field, the related field must have an Index set. A dBASE (.dbf) table file name cannot be more than 8 characters long. A dBASE (.dbf) table field name must be less than or equal to 11 characters. A dBASE (.dbf) table string length must be from 0 to 254 characters. A Visual FoxPro database name can not have a file extension (.dbf). Paradox database name can not have a file extension (.db). Paradox related database must have an Index set on the related field. Paradox 3.x & 4.x related Boolean returns -1 for True and 0 for False. Paradox 5.x related Boolean returns True or False. This is probably due to the fact that Paradox 3 & 4 does not support logical data types. Excel 3.0 & 4.0 does not support multiple sheets in a single .xls file. In dBase III, IV, V, and FoxPro 2.0, 2.5, and 2.6, all field names are stored in UPPERCASE. When relating to Excel 3.0, 4.0, and Text files, Table.Name should have '#' instead of '.' and the file extension (e.g. 'test#xls' and 'test#txt'). Relating to Excel 97 and dBase V will not work unless Microsoft releases respective ISAMs for DAO 3.5. Access databases cannot be read-only or, if using JET, have securities set. Use ODBC if permissions are required on the *.MDB. [此贴子已经被作者于2003-9-30 9:07:52编辑过]
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1楼#
发布于:2003-10-13 08:48
在mo中连接外部表来增强程序信息量能不能给一个具体的例子,加深一下理解,好吗?谢谢
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2楼#
发布于:2003-10-13 11:02
早就有啦,还以为大家看了呢,hoho
http://www.gisempire.com/bbs/dispbbs.asp?BoardID=39&ID=3123&replyID=9654&skin=1 |
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