ibm-information-center/dist/eclipse/plugins/i5OS.ic.db2_5.4.0.1/rbafzmstcon2t.htm

259 lines
16 KiB
HTML
Raw Normal View History

2024-04-02 14:02:31 +00:00
<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" lang="en-US" xml:lang="en-us">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<meta name="dc.language" scheme="rfc1766" content="en-us" />
<!-- All rights reserved. Licensed Materials Property of IBM -->
<!-- US Government Users Restricted Rights -->
<!-- Use, duplication or disclosure restricted by -->
<!-- GSA ADP Schedule Contract with IBM Corp. -->
<meta name="dc.date" scheme="iso8601" content="2005-09-19" />
<meta name="copyright" content="(C) Copyright IBM Corporation 1998, 2006" />
<meta name="security" content="public" />
<meta name="Robots" content="index,follow"/>
<meta http-equiv="PICS-Label" content='(PICS-1.1 "http://www.icra.org/ratingsv02.html" l gen true r (cz 1 lz 1 nz 1 oz 1 vz 1) "http://www.rsac.org/ratingsv01.html" l gen true r (n 0 s 0 v 0 l 0) "http://www.classify.org/safesurf/" l gen true r (SS~~000 1))' />
<meta name="keywords" content="CONNECT (Type 2), SQL statements,
CONNECT (Type 2) statement, in CONNECT (Type 2) statement, server-name, variable,
USER clause, authorization-name, USING clause, password, RESET clause,
SQL (Structured Query Language)" />
<title>CONNECT (Type 2)</title>
<link rel="stylesheet" type="text/css" href="ibmidwb.css" />
<link rel="stylesheet" type="text/css" href="ic.css" />
</head>
<body>
<a id="Top_Of_Page" name="Top_Of_Page"></a><!-- Java sync-link -->
<script language = "Javascript" src = "../rzahg/synch.js" type="text/javascript"></script>
<a name="con2t"></a>
<h2 id="con2t"><a href="rbafzmst02.htm#ToC_830">CONNECT (Type 2)</a></h2><a id="idx1577" name="idx1577"></a><a id="idx1578" name="idx1578"></a>
<a name="aon2t"></a>
<p id="aon2t">The CONNECT (Type 2) statement connects an activation group
within an application process to the identified application server using the rules
for application directed distributed unit of work. This server is then the
current server for the activation group. This type of CONNECT statement is
used if RDBCNNMTH(*DUW) was specified on the CRTSQLxxx command. Differences
between the two types of statements are described in <a href="rbafzmstdiftab2.htm#rcncdif">CONNECT (Type 1) and CONNECT (Type 2) differences</a>. Refer to <a href="rbafzmstch2drda.htm#adduwmg">Application-directed distributed unit of work</a> for more information
about connection states.</p>
<a name="wq1165"></a>
<h3 id="wq1165"><a href="rbafzmst02.htm#ToC_831">Invocation</a></h3>
<p>This statement can only be embedded in an application program or issued
interactively. It is an executable statement that cannot be dynamically prepared.
It must not be specified in Java&trade; or REXX.</p>
<p>CONNECT is not allowed in a trigger, a function, or a procedure if the
procedure is called on a remote application server.</p>
<a name="wq1166"></a>
<h3 id="wq1166"><a href="rbafzmst02.htm#ToC_832">Authorization</a></h3>
<p>The privileges held by the authorization ID of the statement must include
communications-level security. (See the section about security in the <a href="../ddp/rbal1kickoff.htm">Distributed Database Programming</a> book.)</p>
<p>If the application server is DB2 UDB for iSeries, the profile ID of the person issuing the statement
must also be a valid user profile on the application server system, UNLESS:</p>
<ul>
<li>USER is specified. If USER is specified, the USER clause must specify
a valid user profile on the application server system.</li>
<li>TCP/IP is used with a server authorization entry for the application server. If
this is the case, the server authorization entry must specify a valid user
profile on the application server system.</li></ul>
<a name="wq1167"></a>
<h3 id="wq1167"><a href="rbafzmst02.htm#ToC_833">Syntax</a></h3>
<a href="rbafzmstcon2t.htm#synscnct2"><img src="c.gif" alt="Click to skip syntax diagram" /></a>
<pre class="cgraphic"><span><img src="c.gif" alt="Read syntax diagram" longdesc="rbafzmstsyn267.htm"
border="0" /></span><a href="#skipsyn-266"><img src="c.gif" alt="Skip visual syntax diagram"
border="0" /></a>>>-CONNECT--+----------------------------------------+--------->&lt;
+-TO--+-<span class="italic">server-name</span>-+--+---------------+-+
| '-<span><span class="italic">variable</span></span>----' '-<span class="italic">authorization</span>-' |
'-RESET----------------------------------'
authorization:
|--USER--+-<span class="italic">authorization-name</span>-+--USING--+-<span class="italic">password</span>-+------------|
'-<span><span class="italic">variable</span></span>-----------' '-<span><span class="italic">variable</span></span>-'
</pre>
<a name="skipsyn-266" id="skipsyn-266"></a>
<a name="synscnct2"></a>
<h3 id="synscnct2"><a href="rbafzmst02.htm#ToC_834">Description</a></h3>
<dl class="parml">
<dt class="bold">TO <var class="pv">server-name</var><span class="base"> or </span> <var class="pv">variable</var> </dt><a id="idx1579" name="idx1579"></a><a id="idx1580" name="idx1580"></a>
<dd>Identifies the application server by the specified server name or the server
name contained in the variable. If a variable is specified:
<ul>
<li>It must be a character-string variable.</li>
<li>It must not be followed by an indicator variable</li>
<li>The server name must be left-justified within the variable and must conform
to the rules for forming an ordinary identifier</li>
<li>If the length of the server name is less than the length of the variable,
it must be padded on the right with blanks.</li>
<li>The value of the server name must not contain lowercase characters.</li></ul>
<p>When the CONNECT statement is executed, the specified server name
or the server name contained in the variable must identify an application server described
in the local directory.</p>
<p>Let S denote the specified server name or the
server name contained in the variable. S must not identify an existing connection
of the application process.</p>
</dd>
<dt class="bold">USER <var class="pv">authorization-name or variable</var> </dt><a id="idx1581" name="idx1581"></a><a id="idx1582" name="idx1582"></a><a id="idx1583" name="idx1583"></a>
<dd>Identifies the authorization name that will be used to connect to the
application server.
<p>If a <var class="pv">variable</var> is specified, </p>
<ul>
<li>It must be a character string variable.</li>
<li>It must not be followed by an indicator variable. The authorization name
must be left-justified within the variable and must conform to the rules of
forming an authorization name.</li>
<li>If the length of the authorization name is less than the length of the
variable, it must be padded on the right with blanks.</li></ul>
</dd>
<dt class="bold">USING <var class="pv">password or variable</var> </dt><a id="idx1584" name="idx1584"></a><a id="idx1585" name="idx1585"></a><a id="idx1586" name="idx1586"></a>
<dd>Identifies the password that will be used to connect to
the application server.
<p>If password is specified as a literal, it must be
a character string. The maximum length is 128 characters. It must be left
justified. The literal form of the password is not allowed in static SQL or
REXX.</p>
<p>If a <var class="pv">variable</var> is specified, </p>
<ul>
<li>It must be a character-string variable.</li>
<li>It must not be followed by an indicator variable.</li>
<li>The password must be left-justified within the variable.</li>
<li>If the length of the password is less than that of the variable, it must
be padded on the right with blanks.</li></ul>
</dd>
<dt class="bold">RESET </dt><a id="idx1587" name="idx1587"></a>
<dd>CONNECT RESET is equivalent to CONNECT TO <span class="italic">x</span> where <span class="italic">x</span> is the local server name.
</dd>
<dt class="bold">CONNECT <span class="base">with no operand</span></dt>
<dd>This form of the CONNECT statement returns information about the current
server and has no effect on connection states, open cursors, prepared statements,
or locks. The connection information is returned in the connection information
items in the SQL Diagnostics Area (or the SQLCA).
<p>In addition, the DB2_CONNECTION_STATUS
connection information item in the SQL Diagnostics Area (or the SQLERRD(3)
field of the SQLCA) will indicate the status of connection for this unit of
work. It will have one of the following values: </p>
<ul>
<li> 1 - Commitable updates can be performed on the connection for this unit
of work.</li>
<li> 2 - No commitable updates can be performed on the connection for this
unit of work.</li></ul>
</dd>
</dl>
<a name="wq1168"></a>
<h3 id="wq1168"><a href="rbafzmst02.htm#ToC_835">Notes</a></h3>
<p><span class="bold">Successful connection:</span> If the CONNECT statement is
successful: </p>
<ul>
<li>A connection to application server S is created and placed in the current and
held states. The previous connection, if any, is placed in the dormant state.</li>
<li>S is placed in the CURRENT SERVER special register.</li>
<li>Information about the application server is placed in the <var class="pv">connection-information-items</var> in the SQL Diagnostics Area.</li>
<li>Information about application server S is also placed in the SQLERRP and SQLERRD(4)
fields of the SQLCA. If the application server is an IBM&reg; relational database product, the information
in the SQLERRP field has the form <var class="pv">pppvvrrm</var>, where:
<ul>
<li><var class="pv">ppp</var> identifies the product as follows:
<ul class="simple">
<li>ARI for DB2&reg; for VM and VSE</li>
<li>DSN for DB2 UDB for z/OS</li>
<li>QSQ for DB2 UDB for iSeries</li>
<li>SQL for all other DB2 UDB products</li></ul></li>
<li><var class="pv">vv</var> is a two-digit version identifier such as '07'</li>
<li><var class="pv">rr</var> is a two-digit release identifier such as '01'</li>
<li><var class="pv">m</var> is a one-digit modification level such as '0'</li></ul>
<p>For example, if the application server is Version 7 of DB2 UDB for z/OS, the value
of SQLERRP is 'DSN07010'.</p>
<p>The SQLERRD(4) field of the SQLCA
contains values indicating whether application server S allows commitable updates
to be performed. Following is a list of values and their meanings for the
SQLERRD(4) field of the SQLCA on the CONNECT: </p>
<ul>
<li> 1 - commitable updates can be performed. Conversation is unprotected. <sup class="fn"><a href="rbafzmstconj1.htm#fn001">63</a></sup></li>
<li> 2 - No commitable updates can be performed. Conversation is unprotected.</li>
<li> 3 - It is unknown if commitable updates can be performed. Conversation
is protected.</li>
<li> 4 - It is unknown if commitable updates can be performed. Conversation
is unprotected.</li>
<li> 5 - It is unknown if commitable updates can be performed. The connection
is either a local connection or a connection to an application requester driver
program.</li></ul></li>
<li>Additional information about the connection is placed in the SQLERRMC
field of the SQLCA. Refer to <a href="rbafzmstsqlcca.htm#sqlcca">Appendix C. SQLCA (SQL communication area)</a>.</li></ul>
<p><span class="bold">Unsuccessful connection:</span> If the CONNECT statement
is unsuccessful, the connection state of the activation group and the states
of its connections are unchanged.</p>
<p><span class="bold">Implicit connect:</span> Implicit connect will always send
the <var class="pv">authorization-name</var> of the application requester job and will
not send passwords. If the <var class="pv">authorization-name</var> of the application server job
is different or if a password must be sent, an explicit connect statement
must be used.</p>
<p>When TCP/IP is used for connecting to an RDB, an implicit connect is not
bound by the above restrictions. Use of the ADDSVRAUTE and other -SVRAUTE
commands allows one to specify, for a given user under which the implicit
(or explicit) CONNECT is done, the remote authorization-name and password
to be used in connecting to a given RDB.</p>
<p>In order for the password to be stored with the ADDSVRAUTE or CHGSVRAUTE
command, the QRETSVRSEC system value must be set to '1' rather than the default
of '0'. When using these commands for DRDA&reg; connection, it is very important to realize
that the value of the RDB name entered into the SERVER parameter must be in
UPPER CASE. For more information, see Example 2 under Type 2 CONNECT.</p>
<p>For more information about implicit connect, refer to the <a href="../sqlp/rbafykickoff.htm">SQL Programming</a> book. Once a connection to a relational database for a
user profile is established, the password, if specified, may not be validated
again on subsequent connections to the same relational database with the same
user profile. Revalidation of the password depends on if the conversation
is still active. See the <a href="../ddp/rbal1kickoff.htm">Distributed Database Programming</a> book for more details.</p>
<p><span class="bold">SET SESSION AUTHORIZATION:</span> If a SET SESSION
AUTHORIZATION statement has been executed in the thread, a CONNECT to the
local server will fail unless prior to the connect statement, the SYSTEM_USER
value is the same as SESSION_USER.</p>
<p>This incudes an implicit connect due to invoking a program that
specifies ACTGRP(*NEW).</p>
<a name="wq1169"></a>
<h3 id="wq1169"><a href="rbafzmst02.htm#ToC_836">Examples</a></h3>
<p><span class="italic">Example 1:</span> Execute SQL statements at TOROLAB and
SVLLAB. The first CONNECT statement creates the TOROLAB connection and the
second CONNECT statement places it in the dormant state. </p>
<pre class="xmp"> EXEC SQL <span class="bold">CONNECT TO</span> TOROLAB;
(execute statements referencing objects at TOROLAB)
EXEC SQL <span class="bold">CONNECT TO</span> SVLLAB;
(execute statements referencing objects at SVLLAB)</pre>
<p><span class="italic">Example 2:</span> Connect to a remote server specifying
a userid and password, perform work for the user and then connect as another
user to perform further work. </p>
<pre class="xmp"> EXEC SQL <span class="bold">CONNECT TO</span> SVLLAB <span class="bold">USER</span> :AUTHID <span class="bold">USING</span> :PASSWORD;
(execute SQL statements accessing data on the server)
EXEC SQL COMMIT;
(set AUTHID and PASSWORD to new values)
EXEC SQL <span class="bold">CONNECT TO</span> SVLLAB <span class="bold">USER</span> :AUTHID <span class="bold">USING</span> :PASSWORD;
(execute SQL statements accessing data on the server)</pre>
<p><span class="italic">Example 3:</span> User JOE wants to connect to TOROLAB3
and execute SQL statements under the user ID ANONYMOUS which has a password
of SHIBBOLETH. The RDB directory entry for TOROLAB3 specifies *IP for the
connection type.</p>
<p>Before running the application, some setup must be done.</p>
<p>This command will be required to allow server security information to be
retained in i5/OS, if it has not been previously run:</p>
<pre class="xmp"> CHGSYSVAL SYSVAL(QRETSVRSEC) VALUE('1')</pre><p class="indatacontent">This command adds the required server authorization entry:</p>
<pre class="xmp"> ADDSVRAUTE USRPRF(JOE) SERVER(TOROLAB3) USRID(ANONYMOUS) +
PASSWORD(SHIBBOLETH)</pre><p class="indatacontent">This statement, run under JOE's user
profile, will now make the desired connection:</p>
<pre class="xmp"> EXEC SQL <span class="bold">CONNECT TO</span> TOROLAB3;
(execute statements referencing objects at TOROLAB3)</pre>
<p><a id="idx1588" name="idx1588"></a><a id="idx1589" name="idx1589"></a><a id="idx1590" name="idx1590"></a></p>
<hr /><br />
[ <a href="#Top_Of_Page">Top of Page</a> | <a href="rbafzmstconj1.htm">Previous Page</a> | <a href="rbafzmsthcalias.htm">Next Page</a> | <a href="rbafzmst02.htm#wq1">Contents</a> |
<a href="rbafzmstindex.htm#index">Index</a> ]
<a id="Bot_Of_Page" name="Bot_Of_Page"></a>
</body>
</html>