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:
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Date, Time, and Timestamp Literals
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Scalar functions (such as data type, numeric, and string conversion functions)
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Outer joins
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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:
{ 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:
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"