Provided by: mysqltcl_3.051-1_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 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 immadiatly 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 aviable 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)