Chapter 3: Reference Topics for Oracle
Passthrough mode
Passthrough mode allows a DirectConnect
for Oracle client to interact directly with an Oracle database using
native Oracle SQL. When DirectConnect for Oracle is operating as
a standalone gateway, clients are automatically put into passthrough mode.
When used with Adaptive Server Enterprise, DirectConnect for Oracle
performs Transact-SQL parsing.
In passthrough mode, the client program
issues Oracle SQL statements directly to the Oracle database, and
the results are converted into a form that the Open Client interface
understands.
When in passthrough mode, Oracle datatypes
are converted to the following Open Client datatypes:
Table 3-1: Oracle-to-Adaptive
Server datatype conversions for numeric data with create proxy_table
Oracle datatype
|
Open Client datatype
number_mode=0
|
Open Client datatype
number_mode=1
|
Open Client datatype
number_mode=2
|
|---|
number(1,0)
|
tinyint
|
tinyint
|
numeric (1,0)
|
number(2,0)
|
tinyint
|
tinyint
|
numeric (2,0)
|
number(3,0)
|
smallint
|
smallint
|
numeric (3,0)
|
number(4,0)
|
smallint
|
smallint
|
numeric (4,0)
|
number(5,0)
|
int
|
int
|
numeric (5,0)
|
number(p,0) where
6 <= p <= 9
|
int
|
int
|
numeric (p,0)
|
number(p,0) where
10 <= p <= 38
|
numeric (p,0)
|
numeric (p,0)
|
numeric (p,0)
|
number(p,s) where
1 <= p <= 38 and
1 <= s <= 38
|
numeric (p,s)
|
numeric (p,s)
|
numeric (p,s)
|
Table 3-2: Oracle-to-Adaptive
Server datatype conversions for
non-numeric data with create proxy_table
Oracle datatype
|
Adaptive Server datatype
|
|---|
nchar(n)
|
varchar(n)
|
float
|
float
|
char(n)
|
char(n)
|
varchar(n)
|
varchar(n)
|
nvarchar2(n)
|
varchar(n)
|
raw(n)
|
binary(n)
|
clob
|
text
|
nclob
|
text
|
blob
|
image
|
date
|
datetime
|
bfile
|
image
|
long
|
text
|
long raw
|
image
|
timestamp
|
datetime
|
|
Copyright © 2005. Sybase Inc. All rights reserved.
|
|
View this book as PDF 