![]() Unfortunately, Access 95 onwards do not permit Null values in Yes/No fields. ![]() In code, use the constants True and False, equivalent to -1 and 0 respectively. A Logical field can be displayed as Yes/No, True/False, or On/Off. When constructing queries, keep in mind that if a Date/Time field contains a fraction part, it will not match a criteria which is just a date: Now() is not equivalent to Date(), though Int(Now()) is equivalent to Date(). While Now() + 1/24 is theoretically one hour from now, use the DateAdd() function to avoid rounding errors if you plan to use the result in comparisons. Access stores Dates as 8-byte floating point numbers, where the integer part refers to the day, and the fraction part refers to the time. If less than 100 new records will normally be added between synchronizations of the replica databases, this type will probably not be needed.ĭate/Time. Also called a GUID (Globally Unique IDentifier). The ReplicationID is designed to enable off-line replica databases at different sites to assign primary key values without the likelihood of duplicates begin assigned. (Access 95 onwards.) Use this field type only for a foreign key field that looks up a ReplicationID AutoNumber. ![]() For a simple database, use a sequential Long AutoNumber. To look up an AutoNumber in a one-to-many relationship, the foreign key must be the same type (Long or ReplicationID). It can be either a Long integer type, or a ReplicationID (see below), and can be sequential or random. (Access 95 onwards.) The AutoNumber replaces the Counter as an automatically assigned number. To look up a Counter in a one-to-many relationship, use a Long for the field type in the related table.ĪutoNumber. (Access 1 and 2 only.) A Long integer type, automatically assigned by Access. 15 digits of whole dollars, plus four decimal places (hundredths of a cent).Ĭounter. A 64-bit fixed point number, designed to give the accuracy needed for financial data. Access XP introduces the Decimal (96-bit fixed point, scaled), but there is no corresponding data type in VBA (so use Variant).Ĭurrency. This category includes Byte (unsigned 8-bit), Integer (signed 16-bit), Long (signed 32-bit), Single (signed 32-bit), and Double (signed 64-bit). You can and should define a width, but Access doesn't use fixed width storage so is not as wasteful of disk space. Essentially the same as the Character type in xBase. Provided by Allen Browne, Types in Accessįield types in Access are somewhat different to those in xBase. Microsoft Access tips: Data Types in Access Microsoft Access Tips for xBase developers
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