定长数据的宏适用于adDate,adBoolean等,数字的宏适用于adTinyInt, adInteger和adDouble等,变长数据的宏适用于adChar, adVarChar和adVarBinary等
这句话中定长数据和变长数据如何理解,能否举个例子。
adDate,adBoolean,adTinyInt, adInteger和adDouble,adChar, adVarChar和adVarBinary这些都是些什么类型?
这句话中定长数据和变长数据如何理解,能否举个例子。
adDate,adBoolean,adTinyInt, adInteger和adDouble,adChar, adVarChar和adVarBinary这些都是些什么类型?
adVarWChar 202 Null-terminated Unicode character string of less than 256 characters
adLongVarWChar 203 Null-terminated Unicode character string
adVarBinary 204 Binary value of less than 256 bytes
adLongVarBinary 205 Binary value less than or equal to 65469 (4096*16 - 3) bytes
adInteger 3 4-byte signed integer
adSmallInt 2 2-byte signed integer
adDouble 5 Double-precision floating point value
adDate 7 Date value
adUnsignedSmallInt 18 2-byte unsigned integer
adUnsignedInt 19 4-byte unsigned integer
adBoolean 11 Boolean True or False value
adDouble 5 Double-precision floating point number 摘自MSDN。