OpenEdge Data Management: DataServer for Microsoft SQL Server

Table 2–12 depicts mapping between the ABL BLOB data type and its MS SQL Server
equivalent during a schema pull.
Table 2–12: BLOB data type in schema pull
User-defined data types
Data types
MS SQL Server allows you to define your own data types that map to native MS SQL Server
data types. When the DataServer reads the schema information for a user-defined data type, it
reads the MS SQL Server base data type and maps it to the equivalent OpenEdge data type.
Suppose, for example, that you create a data type named phone_number and map it to the char
data type. In the schema holder, the DataServer represents your phone_number data type as a
CHARACTER data type. If you make any changes to a user-defined data type, you must update the
schema holder to reflect those changes.
Arrays
MS SQL Server Data Type OpenEdge Data Type
MSS 2005 MSS 2008 Prior to 10.2B 10.2B and later
VARBINARY(MAX) VARBINARY(MAX) CHAR CHAR, BLOB
IMAGE IMAGE CHAR CHAR, BLOB
The OpenEdge database allows you to define fields as arrays, also called field extents. The
DataServer interprets specially named data source columns of the same data type as an
OpenEdge field with the same number of array elements. You name the data source columns
column_name##1, column_name##2, and so forth, to correspond to an OpenEdge array named
colunm_name. The DataServer creates a single field definition in the schema holder for the field
extents. See the “Migrating an OpenEdge database to MS SQL Server” section on page 7–20
for instructions on adding these columns automatically with the OpenEdge DB to MS SQL
Server utility.
Unknown value (?)
VARBINARY(MAX)
VARBINARY(MAX)
FILESTREAM
The DataServer supports null values. Procedures that use a null value behave exactly as they do
when accessing an Unknown value (?) in an OpenEdge database, except for one
difference—you cannot compare a field to the Unknown value (?) if the field is not allowed to
hold the Unknown value (?) (i.e., is not null-capable). For example, if the custnum field is not
null-capable, the following statement fails at run time:
FIND customer WHERE customer.custnum NE ?
Non-applicable
BLOB
A column that is not null-capable is marked “mandatory” in the schema holder.
2–31