Provided by: mysqltcl_3.052-4ubuntu1_amd64 
NAME
mysqltcl - MySQL server access commands for Tcl
SYNOPSIS
package require Tcl 8.4
package require mysqltcl 3.0
::mysql::connect ?option value...?
::mysql::use handle database
::mysql::sel handle sql-statement ?-list|-flatlist?
::mysql::fetch handle
::mysql::exec handle sql-statement
::mysql::query handle sql-select-statement
::mysql::endquery query-handle
::mysql::map handle binding-list script
::mysql::receive handle sql-statment binding-list script
::mysql::seek handle row-index
::mysql::col handle table-name option
::mysql::col handle table-name optionkist
::mysql::col handle ?option...?
::mysql::info handle option
::mysql::baseinfo option
::mysql::ping handle
::mysql::changeuser user password ?database?
::mysql::result handle option
::mysql::state handle ?-numeric?
::mysql::close ?handle?
::mysql::insertid handle
::mysql::escape ?handle? string
::mysql::autocommit handle boolean
::mysql::commit handle
::mysql::rollback handle
::mysql::nextresult handle
::mysql::moreresult handle
::mysql::warningcount handle
::mysql::isnull value
::mysql::newnull
::mysql::setserveroption handle option
::mysql::shutdown handle
::mysql::encoding handle ?encoding?
_________________________________________________________________
DESCRIPTION
MySQLTcl is a collection of Tcl commands and a Tcl global array that provide access to MySQL database
servers.
MySQLTcl is nothing more than a patched version of a patched version of Hakan Soderstrom's patch of Tom
Poindexter's Sybtcl.
Mysqltcl is binary Tcl library (extension) written in C language that use direkt official MySQL C-API.
Almost all Tcl commands correspond to MySQL C-API functions. For detail documentation see official MySQL
C-API manual.
MYSQLTCL COMMANDS
::mysql::connect ?option value...?
Connect to a MySQL server. A handle is returned which should be used in other mysqltcl commands
using this connection. ::mysql::connect raises a Tcl error if the connection fails.
::mysql::connect read first the options from my.cnf file group mysqltcl. See MySQL documentation
chapter "options files". Possible connection options are:
-host hostname
The host on which the server is located. The local host is used by default.
-user user
The user whose name is used for the connection. The current Unix user-name is used by
default.
-password password
The password that must be used for the connection. If it is not present, the connection is
possible only for users with no password on the server.
-db db If this option is present, db is used as current database, with no need for a call to
mysql::use.
-port port
The port number for the TCP/IP connection, if it's different from the default.
-socket socket
The socket or named pipe for the connection.
-encoding encodingname
The option works similar to -encoding option in fconfigure. It support also special
encoding name binary. By option -binary no converting will be done be reading or writing
to/from MySQL. If option is not set the system encoding (see utf-8) is used. Please test
all input and outputs with another program to check that all is the way you expect it. If
option binary is not used the system procedures Tcl_ExternalToUtfDString (writing) and
Tcl_ExternalToUtf (reading) will be used by option binary the function
Tcl_GetByteArrayFromObj and Tcl_NewByteArrayObj are used. If you want to manipulate binary
date use -encoding binary. By handling textes set your special encoding that you want to
use in your database. Consider what another system access the database and what encoding
they expect. It can useful to use -encoding utf-8. That is standard encoding in some linux
distributions and newer systems.
-compress boolean
Use compression protocol. Default is false
-odbc boolean
The client is an ODBC client. This changes mysqld to be more ODBC-friendly. Default is
false
-noschema boolean
Don't allow the db_name.tbl_name.col_name syntax. This is for ODBC. It causes the parser to
generate an error if you use that syntax, which is useful for trapping bugs in some ODBC
programs. This changes mysqld to be more ODBC-friendly. Default is false
-multistatement boolean
Tell the server that the client may send multiple-row-queries (separated by `;'). If this
flag is not set, multiple-row-queries are disabled. Default is false.
-multiresult boolean
Tell the server that the client can handle multiple-result sets from multi-queries or
stored procedures. This is automatically set if CLIENT_MULTI_STATEMENTS is set.
-localfiles boolean
Enable LOAD DATA LOCAL handling. Default is false.
-foundrows boolean
Return the number of found (matched) rows, not the number of affected rows. Default is
false.
-interactive boolean
Allow interactive_timeout seconds (instead of wait_timeout seconds) of inactivity before
closing the connection. The client's session wait_timeout variable will be set to the
value of the session interactive_timeout variable. Default is false.
-ssl boolean
Switch to SSL after handshake. Default is false
-sslkey string
is the pathname to the key file. Used if -ssl is true
-sslcert string
is the pathname to the certificate file. Used if -ssl is true
-sslca string
is the pathname to the certificate authority file. Used if -ssl is true
-sslcapath string
is the pathname to a directory that contains trusted SSL CA certificates in pem format.
Used if -ssl is true
-sslcipher string
is a list of allowable ciphers to use for SSL encryption. Used if -ssl is true
-reconnect boolean
default is false.
::mysql::use handle database
Associate a connected handle with a particular database. handle must be a valid handle previously
obtained from ::mysql::connect. mysql::use raises a Tcl error if the handle is not valid or if
the database name specified could not be used.
Consider you can use mysqltcl without to specify the database, in this case you must use explizit
schema notation to specify the table in sql.
::mysql::sel $handle {select * from uni.student}
with option connection -noschema you can prohibit such syntax.
::mysql::sel handle sql-statement ?-list|-flatlist?
Send sql-statement to the server.
If sql-statement is a SELECT statement and no -list or -flatlist option is specified, the command
returns the number of rows returned as the result of the query. The rows can be obtained by the
::mysql::fetch and/or the ::mysql::map commands. The resulting rows are called the pending
result.
If sql-statement is a SELECT statement and -list or -flatlist is specified, the command returns
the full list of rows returned as the result of the query in one of two possible formats:
-list generates a list of lists, in which each element is a row of the result.
-flatlist
generates the concatenation of all rows in a single list, which is useful for scanning with
a single foreach.
Example:
% ::mysql::sel $db "SELECT ID, NAME FROM FRIENDS" -list
{1 Joe} {2 Phil} {3 John}
% ::mysql::sel $db "SELECT ID, NAME FROM FRIENDS" -flatlist
{1 Joe 2 Phil 3 John}
Note that both list syntaxes are faster than something like
% ::mysql::sel $db "SELECT ID, NAME FROM FRIENDS"
% ::mysql::map $db {id name} {lappend result $id $name}
% set $result
{1 Joe 2 Phil 3 John}
If sql-statement is a valid MySQL statement, but not a SELECT statement, the command returns -1 after
executing the statement, or an empty string if -list or -flatlist is specified. There is no pending
result in this case.
In any case ::mysql::sel implicitly cancels any previous result still pending for the handle.
::mysql::fetch handle
Returns the next row from result set as Tcl list. mysql::fetch raises a Tcl error if there is no
pending result for handle. mysql::fetch was former named mysqlnext.
::mysql::exec handle sql-statement
Send sql-statement, a MySQL non-SELECT statement, to the server. The handle must be in use
(through ::mysql::connect and ::mysql::use).
::mysql::exec implicitly cancels any previous result pending for the handle.
If sql-statement is a valid MySQL SELECT statement, the statement is executed, but the result is
discarded. No Tcl error is generated. This amounts to a (potentially costly) no-op. Use the
::mysql::sel command for SELECT statements.
::mysql::exec returns the number of affected rows (DELETE, UPDATE). In case of multiple statement
::mysql::exec returns a list of number of affected rows.
::mysql::query handle sql-select-statement
Send sql-select-statement to the server.
mysql::query allow one to send multiple nested queries on one handle (without need to build new
handle or caching results). mysql::query return a query handle that can be used as handle in
commands as (mysql::fetch, ::mysql::map, mysql::seek, mysql::col, mysql::result). After result
proceeding all query must be freed with ::mysql::endquery query-hanlde command.
Example:
set query1 [::mysql::query $db {SELECT ID, NAME FROM FRIENDS}\]
while {[set row [::mysql::fetch $query1]]!=""} {
set id [lindex $row 0]
set query2 [::mysql::query $db "SELECT ADDRESS FROM ADDRESS WHERE FRIENDID=$ID"]
::mysql::map $query2 address { puts "address = $address" }
::mysql::endquery $query2
}
::mysql::endquery $query1
In most cases one should use sql-joins and avoid nested queries. SQL-sever can optimize such
queries. But in some applications (GUI-Forms) where the results are used long time the inner
query is not known before.
::mysql::endquery query-handle
free result memory after ::mysql::query command. You must invoke ::mysql::endquery after each
mysqlquery to not cause memory leaks. See mysqlquery command.
Using ::mysql::endquery on db-handle will free also memory (pending result) after ::mysql::sel
command.
::mysql::map handle binding-list script
Iterate a script over the rows of the pending result. ::mysql::map may consume all rows or only
some of the rows of the pending result. Any remaining rows may be obtained by further
::mysql::fetch or ::mysql::map commands.
handle must be a handle with a pending result from a previous ::mysql::sel command. binding-list
must be a list of one or more variable names. script must be a Tcl script. It may be empty, but
usually it contains one or more commands.
::mysql::map processes one row at a time from the pending result. For each row the column values
are bound to the variables in the binding list, then the script is executed. Binding is strictly
positional. The first variable in the binding list is bound to the first column of the row, and
so on. The variables are created in the current context (if they do not already exist). A
variable name beginning with a hyphen is not bound; it serves as a placeholder in the binding
list. If there are more columns than variables the extra columns are ignored.
The ::mysql::map command is similar to an ordinary foreach. A foreach iterates over the elements
of a list, ::mysql::map iterates over the rows of a pending result. In both cases iteration is
affected by break and continue Tcl commands. The binding list variables retain their last values
after the command has completed.
A simple example follows. Assume $db is a handle in use.
::mysql::sel $db {
select lname, fname, area, phone from friends order by lname, fname
}
::mysql::map $db {ln fn - phone} {
if {$phone == {}} continue
puts [format "%16s %-8s %s" $ln $fn $phone]
}
The ::mysql::sel command gets and sorts all rows from table friends. The ::mysql::map command is
used to format and print the result in a way suitable for a phone list. For demonstration
purposes one of the columns (area) is not used. The script begins by skipping over rows which
have no phone number. The second command in the script formats and prints values from the row.
::mysql::map raises a Tcl error if there is no pending result for handle, or if binding-list
contains more variables than there are columns in the pending result.
::mysql::receive handle sql-statment binding-list script
This command works the same way as the command mysqtclmap but it do not need leading ::mysql::sel
command. The main difference is internal using of MySQL client library. This command use
mysql_use_result from C-API that do not store result on client but try to receive the rows
directly from server. There is also no client cache. This command can be faster as using of
::mysql::sel and by very big resultset will not overload client machine. The scipt should process
the result immediately because it can block table (or tables) for another clients. If performance
matter please test all alternatives separately. You must consider two aspects: memory consumption
and performance.
::mysql::seek handle row-index
Moves the current position among the rows in the pending result. This may cause ::mysql::fetch
and ::mysql::map to re-read rows, or to skip over rows.
Row index 0 is the position just before the first row in the pending result; row index 1 is the
position just before the second row, and so on. You may specify a negative row index. Row index
-1 is the position just before the last row; row index -2 is the position just before the second
last row, and so on. An out-of-bounds row index will cause ::mysql::seek to set the new current
position either just before the first row (if the index is too negative), or just after the last
row (if the index exceeds the number of rows). This is not an error condition.
::mysql::seek returns the number of rows that can be read sequentially from the new current
position. ::mysql::seek raises a Tcl error if there is no pending result for handle.
Portability note: The functionality of ::mysql::seek is frequently absent in other Tcl extensions
for SQL. That is because MySQL C-API client library ofers own result set caching functionality
that lacks another SQL-APIs. That increase the performance because all rows are received at once
and the query does not block the server for another clienst , on the other hand you works on the
cached data can use a lot of memory and are up to date only in the moment of query but not fetch.
::mysql::col handle table-name option
::mysql::col handle table-name optionkist
::mysql::col handle ?option...?
Return information about the columns of a table. handle must be in use. table-name must be the
name of a table; it may be a table name or -current if there is a pending result. One or more
options control what information to return. Each option must be one of the following keywords.
name Return the name of a column.
type Return the type of a column; one of the strings decimal, tiny, short, long, float, double,
null, timestamp, long long, int24, date, time, date time, year, new date, enum, set, tiny
blob, medium blob, long blob, blob, var string, or string. Note that a column of type char
will return tiny, while they are represented equally.
length Return the length of a column in bytes.
table Return the name of the table in which this column occurs.
non_null Return the string "1" if the column is non-null; otherwise "0".
prim_key Return the string "1" if the column is part of the primary key;
otherwise "0".
numeric Return the string "1" if the column is numeric; otherwise "0".
decimals Return the string "1" if the column is non-null; otherwise "0".
The three forms of this command generate their result in a particular way.
[1] If a single option is present the result is a simple list of values; one for each column.
[2] If the options are given in the form of an option list the result is a list of lists. Each
sublist corresponds to a column and contains the information specified by the options.
[3] If several options are given, but not in a list, the result is also a list of lists. In
this case each sublist corresponds to an option and contains one value for each column.
The following is a sample interactive session containing all forms of the ::mysql::col command and their
results. The last command uses the -current option. It could alternatively specify the table name
explicitly.
%::mysql::col $db friends name
name lname area phone
% ::mysql::col $db friends {name type length}
{fname char 12} {lname char 20} {area char 5} {phone char 12}
% ::mysql::sel $db {select * from friends}
% ::mysql::col $db -current name type length
{fname lname area phone} {char char char char} {12 20 5 12}]
::mysql::info handle option
Return various database information depending on the option. The option must be one of the
following keywords.
info Return a String with information about last operation. "Records: 3 Duplicates: 0 Warnings:
0" by INSERT or "Rows matched: 40 Changed: 40 Warnings: 0" by UPDATE statements (read the
manual for mysql_info in MySQL C API documentation)
databases
Return a list of all database names known to the server. The handle must be connected.
dbname Return the name of the database with which the handle is associated. The handle must be in
use.
dbname?
Return the name of the database with which the handle is associated; an empty string if the
handle is connected, but not in use.
host Return the name of the host to which the handle is connected. The handle must be
connected.
host Return the name of the host to which the handle is connected; an empty string if the handle
is not valid.
tables Return a list of all table names in the database with which the handle is associated. The
handle must be in use.
serverversion
Returns the version number of the server as a string.
serverversionid
Returns the version number of the server as an integer.
sqlstate
Returns a string containing the SQLSTATE error code for the last error. The error code
consists of five characters. '00000' means ``no error.'' The values are specified by ANSI
SQL and ODBC. Note that not all MySQL errors are yet mapped to SQLSTATE's. The value
'HY000' (general error) is used for unmapped errors.
state Returns a character string containing information similar to that provided by the
mysqladmin status command. This includes uptime in seconds and the number of running
threads, questions, reloads, and open tables.
::mysql::baseinfo option
return information information that do not need handle.
connectparameters
return all supported connecting options
clientversion
return the version of underlying MYSQL C-API library
::mysql::ping handle
Checks whether the connection to the server is working. If it has gone down, an automatic
reconnection is attempted.
This function can be used by clients that remain idle for a long while, to check whether the
server has closed the connection and reconnect if necessary.
Return True if server is alive
::mysql::changeuser user password ?database?
Changes the user and causes the database specified by database to become the default (current)
database on the connection specified by MySQL. In subsequent queries, this database is the default
for table references that do not include an explicit database specifier.
::mysql::changeuser fails unless the connected user can be authenticated or if he doesn't have
permission to use the database. In this case the user and database are not changed
if database parameter may be set were is no default database.
Cause Error if operation is not succesed
::mysql::result handle option
Return information about the pending result. Note that a result is pending until canceled by a
::mysql::exec command, even if no rows remain to be read. Option must be one of the following
keywords.
cols Return the number of columns in the pending result. There must be a pending result.
cols Return the number of columns in the pending result; an empty string if no result is
pending.
current
Return the current position in the pending result; a non-negative integer. This value can
be used as row-index in the ::mysql::seek command. An error is raised if there is no
pending result.
current?
As above, but returns an empty string if there is no pending result.
rows Return the number of rows that can be read sequentially from the current position in the
pending result. There must be a pending result.
rows Return the number of rows that can be read sequentially from the current position in the
pending result; an empty string if no result is pending.
[::mysql::result $db current] + [::mysql::result $db rows] always equals the total number
of rows in the pending result.
::mysql::state handle ?-numeric?
Return the state of a handle as a string or in numeric form. There is no requirement on handle;
it may be any string. The return value is one of the following strings, or the corresponding
numeric value if -numeric is specified. The states form a progression where each state builds on
the previous.
NOT_A_HANDLE (0)
The string supplied for handle is not a mysqltcl handle at all.
UNCONNECTED (1)
The string supplied for handle is one of the possible mysqltcl handles, but it is not valid
to any server.
CONNECTED (2)
The handle is connected to a server, but not associated with a database.
IN_USE (3)
The handle is connected and associated with a database, but there is no pending result.
RESULT_PENDING (4)
The handle is connected, associated with a database, and there is a pending result.
::mysql::close ?handle?
Closes the server connection associated with handle, causing it to go back to the unconnected
state. Closes all connections if handle is omitted. Returns an empty string. ::mysql::close
raises a Tcl error if a handle is specified which is not valid.
::mysql::insertid handle
Returns the auto increment id of the last INSERT statement.
::mysql::escape ?handle? string
Returns the content of string, with all special characters escaped, so that it is suitable for use
in an SQL statement. This is simpler (faster) than using a general regexp or string map. If
handle is specified C-API function mysql_real_escape_string is used. This is the recommended
usage because in this case current character set is respected.
::mysql::autocommit handle boolean
Sets autocommit mode on if mode is 1, off if mode is 0.
::mysql::commit handle
Commits the current transaction.
::mysql::rollback handle
Rollback the current transaction.
::mysql::nextresult handle
If more query results exist, mysql::nextresult() reads the next query results and returns the
status back to application. returns -1 if no result or number of rows in the result set.
::mysql::moreresult handle
Returns true if more results exist from the currently executed query, and the application must
call mysql::result to fetch the results.
::mysql::warningcount handle
Returns the number of warnings generated during execution of the previous SQL statement.
::mysql::isnull value
Null handling is a known problem with Tcl, especially with DB interaction. The mysql "varchar"
type has two valid blank values, NULL and an empty string. This is where the problem arises; Tcl
is not able to differentiate between the two because of the way it handles strings. Mysql has new
internal Tcl type for null that string representation is stored in global array
mysqltcl(nullvalue) and as default empty string. mysql::isnull can be used for safe check for
null value. Warning mysql::isnull works only reliable if there are no type conversation on
returned rows. Consider row is always Tcl list even when there are only one column in the row.
set row [::mysql::next $handle]
if {[mysql::isnull [lindex $row 1]]} {
puts "2. column of $row is null"
}
if {[mysql::isnull $row]} {
puts "this does not work, because of type conversation list to string"
}
::mysql::newnull
create new null object. It can be used to simulate returned row contents.
::mysql::setserveroption handle option
there are only 2 options now: -multi_statment_on and -multi_statment_off
::mysql::shutdown handle
Asks the database server to shut down. The connected user must have SHUTDOWN privileges.
::mysql::encoding handle ?encoding?
Ask or change a encoding of connection. There are special encoding "binary" for binary data
transfers.
STATUS INFORMATION
Mysqltcl creates and maintains a Tcl global array to provide status information. Its name is
mysqlstatus.
Mysqlstatus elements:
code A numeric conflict code set after every mysqltcl command. Zero means no conflict; non-zero means
some kind of conflict. All conflicts also generate a Tcl error.
All MySQL server conflicts set mysqlstatus(code) to the numeric code of the MySQL error.
Any other conflict sets mysqlstatus(code) to -1.
command
The last failing mysqltcl command. Not updated for successful commands.
message
Message string for the last conflict detected. The same string is returned as the result of the
failing mysqltcl command. Not updated for successful commands.
nullvalue
The string to use in query results to represent the SQL null value. The empty string is used
initially. You may set it to another value.
Backward compatibility
Up from version 3.0 all mysql commands are declared in ::mysql namespace. All names for example
mysqlconnect are also available but deprecated. All old commands have the name pattern mysql{name} and
the most of them are now mysql::{name}. The exception is mysqlnext, which was renamed to mysql::fetch.
BUGS & POSSIBLE MISFEATURES
Deleting any of the mysqltcl commands closes all connections.
AUTHORS
• Tobias Ritzau
• Paolo Brutti
• Artur Trzewik (mail@xdobry.de) - active maintainer
MySQLTcl is derived from a patch of msql by Hakan Soderstrom, Soderstrom Programvaruverkstad, S-12242
Enskede, Sweden. msql is derived from Sybtcl by Tom Poindexter. There are many contributors and bug
reporter that are not mentioned. If you have contributed to mysqltcl and wants to be on the list contact
Artur Trzewik.
3.0 mysqltcl(3)