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<H1>Tclodbc v. 2.3 Reference</H1>

<H2>Contents</H2>

<UL>
<LI><A HREF="#Loading">Installing and Loading the Package</A></LI>

<LI><A HREF="#Connection">Creating a Database Connection</A></LI>

<LI><A HREF="#Database">Database Object</A></LI>

<LI><A HREF="#Statement">Statement Object</A></LI>

<LI><A HREF="#Changes">Changes from previous versions</A></LI>
</UL>

<H1>
<HR WIDTH="100%"><A NAME="Loading"></A>Installing and Loading the Package</H1>

<P>The extension is actually a shared function library. The actual form
of such library depends of the used operating system. For example, in windows
systems these libraries have the extension .dll in their name. The tclodbc
library is thus names tclodbc.dll under windows. </P>

<P>The extension is installed as a tcl package. The installation is most
easily done with an included installation script, <I>setup.tcl</I>. </P>

<P>After installation the extension is loaded simply by command:</P>

<P><B><TT>package require tclodbc</TT></B></P>

<P>This command adds the command <I><TT>database </TT></I>to the tcl command
interpreter (or actually loads the package on demand). Command <I><TT>database
</TT></I>is used for creating database connection objects as well as for
configuring the system data sources.</P>

<H2>Quick start for windows users</H2>

<P>Unzip the distribution file to an arbitrary directory. With pkunzip,
switch -d is required to create subdirectories. After that, run the installation
script. </P>

<P><TT>c:\temp&gt;<B>pkunzip -d tclodbc.zip</B></TT></P>

<P><TT>c:\temp&gt;<B>tclsh setup.tcl <BR>
</B>Installation successful.</TT></P>

<H1>
<HR WIDTH="100%"><A NAME="Connection"></A>Creating a Database Connection</H1>

<P><B><TT>database connect <I>id datasource ?userid? ?password?<BR>
</I></TT></B>or <BR>
<B><TT>database connect <I>id connectionstring</I></TT></B></P>

<UL>
<P>Create a database object identified by id. The object is connected to
a ODBC data source. The first form of the command is applied to a datasource
name, with userid and password where neccessary. The second form uses a
ODBC connection string of the form &quot;Attribute1=Value1;Attribute2=Value2&quot;.
The command returns the id, which is used to refer to the database object.</P>

<P>Example: <BR>
<TT>% database connect db employeebase sysadm xxxxxx <BR>
db</TT></P>

<P>Example 2: <BR>
<TT>% database connect db &quot;DRIVER=Microsoft Paradox Driver (*.db);DBQ=C:\\db&quot;
<BR>
db</TT></P>

<P>This is the default command. The keyword &quot;connect&quot; can be
omitted. It should be used when it is possible that given id may be one
of the other command keywords.</P>
</UL>

<P><B><TT>database configure <I>operation driver attributes</I></TT></B></P>

<UL>
<P>Configure ODBC datasources. A datasource may be added to the system,
reconfigured, or removed. First argument defines the operation from the
set: </P>

<UL>
<LI>add_dsn - add datasource for current user </LI>

<LI>config_dsn - config datasource </LI>

<LI>remove_dsn - remove datasource </LI>

<LI>add_sys_dsn - add system datasource, visible for all users </LI>

<LI>config_sys_dsn - configure system datasource </LI>

<LI>remove_sys_dsn - remove system datasource</LI>
</UL>

<P>Driver argument specifies the driver to be used and the attributes argument
a list of driver specific attribute name and value pairs. Usually at least
the data source name (DSN) parameter should be provided, the rest are driver
dependent.</P>

<P>This form of database command does not create a connection to the database,
even if one is added. Connection is created with some of the commands described
above.</P>

<P>Example: <BR>
<TT>% set driver &quot;Microsoft Access Driver (*.mdb)&quot; <BR>
% set attributes [list &quot;DSN=mydsn&quot; &quot;DBQ=c:\mydb.mdb&quot;
&quot;FIL=MS Access&quot;] <BR>
% database -configure add_dsn $driver $attributes <BR>
OK</TT></P>
</UL>

<P><B><TT>database datasources</TT></B></P>

<UL>
<P>Returns a list of currently configured ODBC data sources in pairs {{datasource
name} {driver name}}</P>
</UL>

<P><B><TT>database drivers</TT></B></P>

<UL>
<P>Returns a list of currently configured ODBC drivers in pairs {{driver
name} {list of driver attributes}}</P>
</UL>

<H1>
<HR WIDTH="100%"><A NAME="Database"></A>Database Object Interface</H1>

<P>Database object is a dynamically allocated object, created by the database
command. The object provides the following methods. The methods are called
as commands after the database object identifier.</P>

<P><B><I><TT>&lt;any valid SQL-clause&gt; ?argtypedefs? ?args?</TT></I></B></P>

<UL>
<P>Almost all necessary functionality can be provided through this simple
syntax. The given SQL-clause is executed in the DBMS, and the result, if
any, is returned in a tcl list. </P>

<P>If the command returns a single column result set, the returned string
is a straightforward list or an empty string, if nothing is found. If the
command returns a multiple column result set, a tcl list of lists is returned,
where a sublist represents a single row of the result. If the SQL-clause
does not return a result set (as with update, insert or delete clause), 
the command returns an integer value giving the amount of rows touched.</P>

<P>SQL-arguments may be given after the SQL-clause, while the argument
positions are marked with '?' in the SQL- clause. This mechanism is more
useful with precompiled statements and explained with statement object
interface in detail. A simpler mechanism of argument substitution is the
natural way of using tcl variables for substituting values straight to
the SQL-clause. </P>

<P>Examples: <BR>
<TT>% database db employeebase sysadm xxxxxx <BR>
db <BR>
% set ids [db &quot;select id from employees where salary &lt; 1000&quot;] <BR>
{222 333 444} <BR>
% set id [lindex $ids 0] <BR>
222 <BR>
% db &quot;select firstname, surname from employees, where id = $id&quot;
<BR>
{{Jonathan Clarke}} <BR>
% db &quot;update employees set salary = 2000 where id = $id&quot; <BR>
1</TT></P>
</UL>

<P><B><TT>disconnect </TT></B></P>

<UL>
<P>disconnect disconnects the database object from the data source and
clears it from the interpreter. </P>
</UL>

<UL>
<P>Example: <BR>
<TT>% database db employeebase sysadm xxxxxx <BR>
db <BR>
% db disconnect <BR>
OK</TT></P>
</UL>

<P><B><TT>set <I>option value</I></TT></B></P>

<UL>
<P>Set command is used for setting various connection-specific attributes.
Currently supported options and their valid values are listed in following
table. Check some odbc reference for detailed description of the different
options.</P>

<CENTER><TABLE BORDER=1 CELLPADDING=5 >
<TR>
<TH><B><FONT SIZE=+1>Option</FONT></B></TH>

<TH><B><FONT SIZE=+1>Values</FONT></B></TH>
</TR>

<TR>
<TD><TT>autocommit</TT></TD>

<TD><TT>boolean (0/1, on/off)</TT></TD>
</TR>

<TR>
<TD><TT>concurrency</TT></TD>

<TD><TT>readonly<BR>
lock<BR>
values<BR>
rowver</TT></TD>
</TR>

<TR>
<TD><TT>maxrows</TT></TD>

<TD><TT>numeric value</TT></TD>
</TR>

<TR>
<TD><TT>timeout</TT></TD>

<TD><TT>numeric value</TT></TD>
</TR>

<TR>
<TD><TT>maxlength</TT></TD>

<TD><TT>numeric value</TT></TD>
</TR>

<TR>
<TD><TT>multisets</TT></TD>

<TD><TT>boolean</TT></TD>
</TR>

<TR>
<TD><TT>rowsetsize</TT></TD>

<TD><TT>numeric value</TT></TD>
</TR>

<TR>
<TD><TT>cursortype</TT></TD>

<TD><TT>static<BR>
dynamic<BR>
forwardonly<BR>
keysetdriven</TT></TD>
</TR>

<TR>
<TD><TT>encoding<BR>
(requires tcl 8.1)</TT></TD>

<TD><TT>any valid encoding name</TT></TD>
</TR>

<TR>
<TD><TT>noscan</TT></TD>

<TD><TT>boolean (0/1, on/off)</TT></TD>
</TR>
</TABLE></CENTER>

<P>In tcl 8.1 strings are stored in unicode form, but ODBC API uses only
old-fashioned 8-bit character strings. Therefore it is possible to set
an encoding to a database object. This encoding is used when transforming
strings from and to the database. While encoding is a connection specific
value, it is even possible to have simultaneous connection to databases
with different encodings, and transfer data correctly from one to another.
Encoding defaults to system encoding, which is suitable in most cases.
</P>

<P>For example: An ODBC-connection is by default in an autocommit-mode.
This means that any statement is commited at once, thus leaving no records
locked. If special transaction handling should be used, the connection
may be set in non-autocommit mode. After this the commit and rollback methods
are used for transaction handling.</P>

<P>Examples: <BR>
<TT>% database db artbase sysadm xxxxxx <BR>
db <BR>
% db set autocommit off <BR>
OK <BR>
% db &quot;update article set groupid=5 where artid &gt; 1000&quot; <BR>
12 <BR>
% db rollback <BR>
OK <BR>
% db &quot;update article set groupid=6 where artid &gt; 1000&quot; <BR>
12 <BR>
% db commit <BR>
OK</TT></P>
</UL>

<P><B><TT>get <I>option</I></TT></B></P>

<UL>
<P>Get command is used for querying current value of various connection-specific
attributes. Theck the table above for list of supported options. </P>
</UL>

<P><B><TT>commit </TT></B></P>

<UL>
<P>With connection in autocommit mode, method commit commits the current
transaction. See examples in autocommit section.</P>
</UL>

<P><B><TT>rollback </TT></B></P>

<UL>
<P>With connection in autocommit mode, method rollback cancels the current
transaction. See examples in autocommit section.</P>
</UL>

<P><B><TT>tables <I>?matchpattern?</I></TT></B></P>

<UL>
<P>Method tables lists all tables in the database which name matches argument. 
Note, that match is determined using sql syntax, with % and _ as wildcards.
With no argument, all tables are listed. The result is a list
of kvintuples: {TABLE_QUALIFIER TABLE_OWNER TABLE_NAME TABLE_TYPE REMARKS}
</P>
</UL>

<P><B><TT>columns <I>?tablename?</I></TT></B></P>

<UL>
<P>Method columns lists the columns in the database, or the columns in
the specified table, if one given. The result is a list of: {TABLE_QUALIFIER
TABLE_OWNER TABLE_NAME COLUMN_NAME DATA_TYPE TYPE_NAME PRECISION LENGTH
SCALE RADIX NULLABLE REMARKS}</P>
</UL>

<P><B><TT>indexes <I>tablename</I></TT></B></P>

<UL>
<P>Method indexes lists the indexes of a specified table. The result is
a list of: {TABLE_QUALIFIER TABLE_OWNER TABLE_NAME NON_UNIQUE INDEX_QUALIFIER
INDEX_NAME TYPE SEQ_IN_INDEX COLUMN_NAME COLLATION CARDINALITY PAGES FILTER_CONDITION}</P>
</UL>

<P><B><TT>typeinfo <I>typeid</I></TT></B></P>

<UL>
<P>Method typeinfo returns driver specific information of given sql type.
The information is a tuple of: {TYPE_NAME DATA_TYPE PRECISION LITERAL_PREFIX LITERAL_SUFFIX
CREATE_PARAMS NULLABLE CASE_SENSITIVE SEARCHABLE UNSIGNED_ATTRIBUTE MONEY AUTO_INCREMENT LOCAL_TYPE_NAME
MINIMUM_SCALE MAXIMUM_SCALE}</P>
</UL>

<P><B><TT>statement <I>id &lt;sql clause&gt;|tables|columns|typeinfo ?argtypedefs?
</I></TT></B></P>

<UL>
<P>Method statement creates new statement objects of one of the three types:
sql query, table query or column query, depending of the last argument:
valid sql-clause, or an identifier 'tables' or 'columns'. </P>

<P>Statements are similar to queries executed directly on a database object,
but when created, statement it is merely precompiled for furher use. This
is useful for efficiency reasons, should the same query be executed several
times. Precompiled statements may be used with sql argumens.</P>

<P>A statement is given a textual id similar to database object. Further,
the statement object is called simply by its id, following possible query
arguments. The command returns the id</P>

<P>Tclodbc tries automatically determine proper argument types for each
argument. Some drivers do not support this function, and therefore the
user may explicitly define the correct argument types.</P>

<P>The syntax of an argument type definition is the following:</P>

<P>?type? ?scale? ?precision?</P>

<P>The type cast is interpreted from the left, so that e.g. the scale and
precision may be left out, if not needed. </P>

<P>Currently recognised sql type names are standard types: </P>

<UL>
<LI>CHAR</LI>

<LI>NUMERIC</LI>

<LI>DECIMAL </LI>

<LI>INTEGER </LI>

<LI>SMALLINT</LI>

<LI>FLOAT</LI>

<LI>REAL</LI>

<LI>DOUBLE</LI>

<LI>VARCHAR </LI>
</UL>

<P>and the extended types: </P>

<UL>
<LI>DATE </LI>

<LI>TIME </LI>

<LI>TIMESTAMP</LI>

<LI>LONGVARCHAR</LI>

<LI>BINARY</LI>

<LI>VARBINARY</LI>

<LI>LONGVARBINARY</LI>

<LI>BIGINT</LI>

<LI>TINYINT</LI>

<LI>BIT </LI>
</UL>

<P>Also datatypes standard numerical counterparts may be used instead of
the string names.</P>

<P>Examples: <BR>
<TT>% db statement s &quot;select fullname from article where id=132&quot;
<BR>
s <BR>
% s <BR>
{FullName132} <BR>
% db statement s2 &quot;select fullname from article where id1=?&quot;
INTEGER<BR>
s2 <BR>
% s2 132 <BR>
{FullName132} </TT></P>
</UL>

<P><B><TT>eval <I>proc &lt;sql clause&gt; ?argtypedefs? ?args?</I></TT></B></P>

<UL>
<P>Method eval first executes the given sql clause, and then evaluates
the given tcl procedure for each row in the result set. The argument count
of the procedure must match the column count in the query. Only single
row is read in the memory at a time this saving memory compared to e.g:
foreach i [db &quot;select...&quot;] {...}</P>

<P>This command is particulary useful, when large tables are to be iterated
once. In this case we do not neccessarily need a separate statement object,
but also do not want to read the whole table to memory at one time. </P>

<P>Example: <BR>
<TT>% proc output {name value} {puts $name $value} <BR>
% db eval output &quot;select name, value from table1&quot; <BR>
{{ab 123}{cd 456}}</TT></P>
</UL>

<P><B><TT>read <I>arrayspec &lt;sql clause&gt; ?argtypedefs? ?args?</I></TT></B></P>

<UL>
<P>Method read reads data from the database to a tcl array or arrays. The
first data columnn is used as index for the array, and the rest of the
columns are stored as to the array. The basic case is a query that results
two columns, first of which is a key of a table, and the next a description
of some sort for the key value.</P>

<P>The array may be specified in two ways. The first way is to specify
a list of array names which are used for array names for each data column.
Thus, the count of given names must be equal to the count of returned data
columns (minus the first column containing the key). (Example 1) </P>

<P>The second way is to specify only a single arrayname, which is used
as two-dimensional array. The array index in this case is constructed from
the key column value and column label, separated by comma. (Example 2)</P>

<P>It should be noted, that it is not recommended to read large tables
to arrays for two reasons. First, if the data is subject to changes in
multi-user database, the changes do not reflect to the data already read
in the array. The other thing is memory consumption. Is the table is large,
it also consumes pretty much memory if read in at once. It is recommended
to use either database eval command, or separate statement object to do
the iteration of large amounts of data. On the other hand, this command
provides a very simple syntax for reading relatively stable name-value
parameter pairs to tcl array, from which they are easily referenced. </P>

<P>Example 1: <BR>
<TT>% db read {name description} &quot;select id, name, description from
table2&quot; <BR>
OK <BR>
% puts $name(123) <BR>
Name123<BR>
% puts $description(123) <BR>
Description123</TT></P>

<P>Example 2: <BR>
<TT>% db read table2 &quot;select id, name, description from table2&quot;
<BR>
OK <BR>
% puts $table2(123,name) <BR>
Name123<BR>
% puts $table2(123,description) <BR>
Description123</TT></P>
</UL>

<H1>
<HR WIDTH="100%"><A NAME="Statement"></A>Statement Object Interface </H1>

<P>Statement object is a dynamically allocated object, created by the statement
method of a database object command. The object provides the following
methods. The methods are called as commands after the statement object
identifier.</P>

<P><B><I><TT>run ?args?</TT></I></B></P>

<UL>
<P>Command run executes the statement and returns the whole result set
immediately. The command may be followed with the list of sql arguments,
if the statement expects them.</P>

<P>Empty argument is interpreted as null value. Notice that the arguments
are given as a list of arguments. Therefore an argument given as {} is
a empty list of arguments, while {{}} is a list of one argument, which
is null. Safest way to create argument lists is through the tcl list command.</P>

<P>This is the default command. The keyword &quot;run&quot; can be omitted.
It should be used when it is possible that given argument value may be
one of the other command keywords.</P>

<P>Example:<BR>
<TT>% database db employeebase sysadm xxxxxx <BR>
db <BR>
% db statement readall &quot;select * from employees&quot; <BR>
readall <BR>
% readall <BR>
{{xx yy zz} {aa bb cc} {rr tt yy}} <BR>
% db statement read_salary &quot;select salary from employees where id
= ?&quot; <BR>
read_salary <BR>
% read_salary 222 <BR>
2000 <BR>
% db statement update_salary &quot;update employees set salary = ? where
id = ?&quot; <BR>
update_salary <BR>
% update_salary {3000 222} <BR>
1 </TT></P>
</UL>

<P><B><TT>execute <I>?args?</I></TT></B></P>

<UL>
<P>Method execute executes the given statement, but does not return the
result set. If the statement returns a result set, rows may be read one
by one with method fetch.</P>
</UL>

<P><B><TT>moreresults</TT></B></P>

<UL>
<P>The result of SQL queries is a list of list of rows when the database
has been configure with <TT>multisets</TT> true.</P>
<P>Example:
<PRE>
   db set multisets 1
   db statement ssss "XXXX"
   puts [ssss execute]
   set i 0
   while {1} {
      puts "---- RESULTS $i"
      while {[set row [ssss fetch]] != {}} {
           puts $row
      }
      if {![ssss moreresults]} {
           break
      }
      incr i
   }
</PRE>
</P>
</UL>

<P><B><TT>fetch ?arrayName? ?columnNames?</TT></B></P>

<UL>
<P>Method fetch is used for reading one row from the result set at a time
after executing it by method execute. Sometimes, if the result set is large,
it is not convenient to load it to memory at once, but rather traverse
thru it one record at a time e.g. making neccessary output or update one
by one.</P>

<P>The first form without <I>arrayName </I>returns the row data, or an
empty string when there is nothing more to read. </P>

<P>Example:<BR>
<TT>% db statement emp_data &quot;select * from employees&quot; <BR>
emp_data<BR>
% emp_data execute<BR>
OK<BR>
% while {[set row [emp_data fetch]] != {}} {puts [lindex $row 5]}<BR>
2000<BR>
3000<BR>
4000<BR>
%</TT></P>

<P>The other form reads the data to an array. Statement column labels or,
if given, defined column names are used as array indices. If the column
labels are explicitly defined, their count must match the number of actual
data columns. </P>

<P>This provides a convenient way for storing the data straight to named
array instead of indexing a straight list. Here the command returns a boolean
value indicating successful fetch or do data condition.</P>

<P>Example (same result as above, with substantially more readable code):<BR>
<TT>% db statement emp_data &quot;select * from employees&quot; <BR>
emp_data<BR>
% emp_data execute<BR>
OK<BR>
% while {[read_salary fetch row]} {puts $row(Salary}}<BR>
2000<BR>
3000<BR>
4000<BR>
%</TT></P>
</UL>

<P><B><TT>rowcount </TT></B></P>

<UL>
<P>Method rowcount returns the number of rows affected by last execution
of insert, update or delete statement. Certain drivers support also
getting the count of rows in open result set after select command,
but this is not generally applicable.</P>
</UL>

<P><B><TT>columns <I>?attribute attribute ...?</I> </TT></B></P>

<UL>
<P>Method columns returns a list of statement columns attributes. ODBC
supports various column attributes. The returned attributes are specified
with arguments. The default attribute, in none given, is column label.</P>

<P>Currently supported attributes are: </P>

<UL>
<LI>label - column label </LI>

<LI>name - column name in the original table, if available </LI>

<LI>displaysize - the maximum string length of the column data </LI>

<LI>type - standard numeric sql type </LI>

<LI>typename - db specific type name string </LI>

<LI>precision - the precision of the column, if applicable </LI>

<LI>scale - the scale of the column, if applicable </LI>

<LI>nullable - 1 if the column is nullable </LI>

<LI>updatable - 1 if the column is updatable </LI>

<LI>tablename - source table of the column, if available </LI>

<LI>qualifiername - qualifier name of the table, if available </LI>

<LI>owner - owner name of the table, if available </LI>
</UL>
</UL>

<P><B><TT>set <I>option value</I></TT></B></P>

<UL>
<P>Set command is used for setting statement-specific attributes. Currently
supported options and their valid values are listed in following table.
Check some odbc reference for detailed description of the different options.</P>

<CENTER><TABLE BORDER=1 CELLPADDING=5 >
<TR>
<TH><B><FONT SIZE=+1>Option</FONT></B></TH>

<TD><B><FONT SIZE=+1>Values</FONT></B></TD>
</TR>

<TR>
<TD><TT>concurrency</TT></TD>

<TD><TT>readonly<BR>
lock<BR>
values<BR>
rowver</TT></TD>
</TR>

<TR>
<TD><TT>maxrows</TT></TD>

<TD><TT>numeric value</TT></TD>
</TR>

<TR>
<TD><TT>timeout</TT></TD>

<TD><TT>numeric value</TT></TD>
</TR>

<TR>
<TD><TT>maxlength</TT></TD>

<TD><TT>numeric value</TT></TD>
</TR>

<TR>
<TD><TT>rowsetsize</TT></TD>

<TD><TT>numeric value</TT></TD>
</TR>

<TR>
<TD><TT>cursortype</TT></TD>

<TD><TT>static<BR>
dynamic<BR>
forwardonly<BR>
keysetdriven</TT></TD>
</TR>

<TR>
<TD><TT>noscan</TT></TD>

<TD><TT>boolean (0/1, on/off)</TT></TD>
</TR>
</TABLE></CENTER>
</UL>

<P><B><TT>get <I>option</I></TT></B></P>

<UL>
<P>Get command is used for querying current attribute values. Theck the
table above for list of supported options. </P>
</UL>

<P><B><TT>drop </TT></B></P>

<UL>
<P>Method drop drops the statement from the memory and clears the command
from the interpreter.</P>
</UL>

<P><B><TT>eval <I>proc ?args?</I></TT></B></P>

<UL>
<P>See <I>database eval</I> for description.</P>
</UL>

<P><B><TT>read <I>arrayspec ?args?</I></TT></B></P>

<UL>
<P>See <I>database read </I>for description.</P>
</UL>

<H1>
<HR WIDTH="100%"><A NAME="Changes"></A>Changes from Previous Versions</H1>

<H2>v. 1.5</H2>

<UL>
<P>Autocommit on|off command is replaced with more general set and get
commands, which are used for setting all kinds of database connection object
properties. Old syntax is still supported.</P>

<P>Some drivers returned last non-null values in a column having a null
value. Bug was corrected.</P>
</UL>

<H2>v. 1.6</H2>

<UL>
<P>Argument type definition was moved from statement execution to statement
object creation. Now tclodbc tries to determine the argument types automatically,
if the driver supports it, but if it does not, the user has the option
of giving types explicitly. The old syntax is still supported, too.</P>
</UL>

<H2>v. 1.7</H2>

<UL>
<P>The sources completely rewritten to allow conditional compling for both
tcl 7.6 and 8.0. Under tcl 7.6 tcl-objects are implemented using reference
counted DStrings instead of Tcl_Obj's. The performance in some situations
may not be exactly the same as with tcl 8.0, but it works anyway. The command
interface has no changes since the previous version.</P>
</UL>

<H2>v. 2.0</H2>

<UL>
<P>Added couple of configuration options to database and statement set
and get commands. Added arrayName option to the <I>statement fetch </I>command.
Removed global private interpreter to ensure thread safety, which is nice
with thread safe tcl 8.1 interpreter. </P>

<P>Added <I>read </I>an <I>eval </I>command to both database and statement
objects.</P>

<P>Unicode support is added with tcl 8.1. Now it is possible to specify
encoding to a database connection. UTF-8 is used as string internal representation,
but any strings passed from and to an odbc connection are encoded as specified.
More details in tcl 8.1 documentation.</P>

<P>Distribution version now includes compiled dll's for tcl 7.6, 8.0 and
8.1, all in one zipfile. Installation to a tcl package automated with a
simple installation script.</P>

<P>Corrected bug related to large column handling. Now should be able to 
handle properly even large variable length binary columns. There remains
still problems with some drivers.</P>
</UL>

<H2>v. 2.1</H2>

<UL>
<P>Configuration option noscan for database and statement objects. This is 
particularily useful when storing tcl strings as string literals.
</P>

<P>Added <I>typeinfo </I> command for database object</P>

<P>Added <I>rowcount </I> command for statement object</P>

<P>Some  bugs are fixed, most of them relating to variable length
column handling. </P>

<h3>Removed old syntax:</h3>

<p>Syntax: db autocommit on/off was removed. Correct syntax for the same thing
is:<br>db <i>set</i> autocommit on/off</P>

<p>Also, statement object argument typecast was finally removed from 
statement execution time. Correct syntax is to define statement arguments
at statement object creation time.</P>

</UL>

<H2>v. 2.2</H2>
<UL>

<p>Binary column handling changed. In earlier versions binary data was handled in hexadecimal
form if the driver supported binary-character conversion. Now binary data is handled in native
binary form. Example code of binary data handling is added to samples.
</p>

<p>Bugfix in long column handling: handle also SQL_NO_TOTAL return value from SqlGetData(). 
</p>

<p>Corrected a misspelling in option name <i>maxlength</i>. The earlier misspelled form 
<i>maxlenght</i> is still supported for compatibility reasons.
</p>

</UL>

<H2>v. 2.3</H2>
<UL>

<p>Return value from update/insert/delete statement changed. Earlier returned always "OK" for
successful execution. Now returns the count of rows updated/inserted/deleted. If now rows were
touched, returns 0, which normally means an error.
</p>

<p>Bugfix in setting database options. Some options always raised an error: 
unknown encoding ..."
</p>

<p>Now works also with MS Access MEMO fields. Older version returns some carbage in memo text
data after actul value.
</p>

</UL>

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