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For many of these Unicode functions, the ODBC Programmer's Reference provides incorrect or
ambiguous descriptions for some of the function arguments. Specifically, this problem
relates to arguments that are used to specify the length of character string input and
output values."
Regardless of what the documentation says for each ODBC function, the following paragraph
from the Unicode section of "Chapter 17: Programming Considerations" in the ODBC
Programmer's Reference is the ultimate rule to use for length arguments in Unicode
"Unicode functions that always return or take strings or length arguments are passed as
count-of-characters. For functions that return length information for server data, the
display size and precision are described in number of characters. When a length
(transfer size of the data) could refer to string or nonstring data, the length is
described in octet lengths. For example, SQLGetInfoW will still take the length as
count-of-bytes, but SQLExecDirectW will use count-of-characters."
This means that if the argument in question describes the length of another argument that
is always a string (typically represented as a SQLCHAR), then the length reflects the
number of characters in the string. If the length argument describes another argument that
could be a string or some other data type (typically represented as a SQLPOINTER), the
length is in bytes.
Driver Support"
* PostgreSQL seems to correct use UCS-2.
* MS SQL Server on Windows & Linux. Obviously correctly uses UCS-2.
* mysql: Seems to be broken. To handle this, probably need to provide a 'charset' option
that causes us to convert to the given charset and use the ANSI/ASCII calls and data types.
* FreeTDS
Definitely use 0.91 or later.
Have seen reference to a new --wide-unicode flag for 0.92+ (broken in 0.91) which causes
SQL_WCHAR to equal wchar_t instead of UCS-16.
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