OLE DB
Using ODBC escape Sequences
ODBC defines extensions that are common to most backend DBMSs. To
cover vendor-specific extensions, the syntax defined by ODBC uses the
escape clause provided by the X/Open and SQL Access Group (SAG) SQL draft
specifications. OLE DB supports ODBC escape sequences directly.
For example, some of the extensions defined in ODBC are:
-
Date, Time, and Timestamp Literals
-
Scalar functions (such as data type, numeric, and string
conversion functions) -
Outer joins
-
Procedure Calls
Note
For maximum portability, you should use escape sequences in your
applications.
Syntax
For example, PowerBuilder uses the date, time, and timestamp escape
clauses as the default formats for data manipulation. The syntax for each
of these escape clauses is:
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{ d yyyy-mm-dd } { t hh:mm:ss } { ts yyyy-mm-dd hh:mm:ss:[fff[fff]] } |
Example
Each of the following statements updates employee Henry Jones’s
start time in the Employee table. The first statement uses the escape
clause, and the second statement uses native syntax for a time
column:
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UPDATE Employee SET start_time = {t 08:30:00} WHERE emp_name = "Henry Jones" UPDATE Employee SET start_time = (08:30:00) WHERE emp_name = "Henry Jones" |