Accessing Unicode data

PowerBuilder can connect, save, and retrieve data in both ANSI/DBCS
and Unicode databases, but it does not convert data between Unicode
and ANSI/DBCS. When character data or command text is sent
to the database, PowerBuilder sends a Unicode string. The driver must
guarantee that the data is saved as Unicode data correctly. When PowerBuilder retrieves
character data, it assumes the data is Unicode.

A Unicode database is a database whose character set is set
to a Unicode format, such as UTF-8, UTF-16, UCS-2, or UCS-4. All
data must be in Unicode format, and any data saved to the database
must be converted to Unicode data implicitly or explicitly.

A database that uses ANSI (or DBCS) as its character set might
use special datatypes to store Unicode data. These datatypes are NCHAR and NVARCHAR2. Columns
with this datatype can store only Unicode data.
Any data saved into such a column must be converted to Unicode explicitly.
This conversion must be handled by the database server or client.

A constant string is regarded as a char type by Oracle and
its character set is NLS_CHARACTERSET. However, if the
datatype in the database is NCHAR and its character
set is NLS_NCHAR_CHARACTERSET, Oracle performs
a conversion from NLS_CHARACTERSET to NLS_NCHAR_CHARACTERSET.
This can cause loss of data. For example, if NLS_CHARACTERSET
is WE8ISO8859P1 and NLS_NCHAR_CHARACTERSET is
UTF8, when the Unicode data is mapped to WE8ISO8859P1, the Unicode
data is corrupted.

If you want to access Unicode data using NCHAR and NVARCHAR2 columns or
stored procedure parameters, use PowerBuilder variables to store the Unicode
data in a script using embedded SQL to avoid using a constant string, and
force PowerBuilder to bind the variables.

By default, the Oracle database interfaces bind all string
data to internal variables as the Oracle CHAR datatype
to avoid downgrading performance. To ensure that NCHAR and NVARCHAR2 columns
are handled as such on the server, set the NCharBind database parameter
to 1 to have the drivers bind string data as the Oracle NCHAR datatype.

For example, suppose table1 has a column c1 with
the datatype NVARCHAR2. To insert Unicode data
into the table, set DisableBind to 0, set NCharBind to 1, and use
this syntax:

If an Oracle stored procedure has an NCHAR or NVARCHAR2 input
parameter and the input data is a Unicode string, set the BindSPInput
database parameter to 1 to force the Oracle database to bind the
input data. The Oracle database interfaces are able to describe
the procedure to determine its parameters, therefore you do not
need to set the NCharBind database parameter.

For a DataWindow object to access NCHAR and NVARCHAR2 columns
and retrieve data correctly, set both DisableBind and StaticBind
to 0. Setting StaticBind to 0 ensures that PowerBuilder gets an accurate
datatype before retrieving.

TimeStamp datatype

The TimeStamp datatype in Oracle9i and
later is an extension of the Date datatype.
It stores the year, month, and day of the Date value plus hours, minutes,
and seconds:

The fractional_seconds_precision value
is optional and provides the number of digits for indicating seconds.
The range of valid values for use with PowerBuilder is 0-6.