HighStone uses only a core set of Data Types when creating Fields/Columns in Data Tables. The prime list of Data Types is defined below. Other Data Types are not adopted by HighStone - though if such items are defined in data tables then HighStone may still be able to read such items.
Note: Access users will see that the standard Field Type Name listed here is that used by the SQL Definitions, and not necessarily the name put on front forms by the Access Application.
|
Data Type |
Description |
SQL Server |
Access |
|
Integer |
Integer numeric. 32 bit Integer |
INT |
INTEGER |
|
Identity Integer |
Integer Identifier field on a table |
INT IDENTITY |
COUNTER |
|
Double |
Double precision floating point numeric. |
FLOAT |
DOUBLE |
|
Date / Time |
Calendar Date - always with a Time Element. |
SMALLDATETIME |
DATE |
|
String (Fixed) |
Fixed Length Text Value. Has a maximum limit of 255 characters, but is typically much less. |
VARCHAR(n) |
VARCHAR(n) |
|
Text (undefined length) |
For text of excessive or unknown length. |
TEXT |
LONGTEXT |
|
Boolean |
True / False values |
BIT |
YESNO |
|
GUID |
32 Bit Unique Identifier |
UNIQUEINTEGER |
GUID |
|
BLOB |
Binary Large Object - Generally not held in the database |
IMAGE |
LONGBINARY |
A note to state that in Access the 'ALLOW NULL' against a value in a table field is the Default option, whilst in SQL Server the default is the reverse of this.
Further, Boolean data fields in SQL Server (BIT) are subject to the 'ALLOW NULL' setting - whilst in Access the setting does not apply (values are always entered if not specified).
The result of this is that the ALLOW NULL status should be set explicitly for all data types, including Boolean, when creating Columns in Tables.