rdebug_set_variable.html

<h3>NAME</h3>
rdebug_set_variable(): Modify value of local or user defined variable.

<h3>TYPE</h3>
Procedure

<h3>DESCRIPTION</h3>
<p>
	This procedure is part of the <a href="rdebug_api.html">rdebug API</a>.
</p>
<p>
	<i>rdebug_set_variable()</i> allows the <i>debugger</i> to modify values of
	<i>worker's</i> visible local routine variables and user defined variables.
</p>

<p>
	Variables which are eligible for modifications are those presented by
	<a href="rdebug_watch_variables.html">rdebug_watch_variables()</a>. These are
	the local variables in scope at the <i>worker's</i> currently executing routine,
	and the user defined variables used anywhere by that routine. 
</p>
<p>
	Calling <i>rdebug_set_variable()</i> should take place while the <i>worker</i>
	is being suspended on a <a href="rdebug_set_breakpoint.html">breakpoint</a> or
	by a step (<a href="rdebug_step_into.html">into</a>/<a 
		href="rdebug_step_out.html">out</a>/<a 
		href="rdebug_step_over.html">over</a>). 
	During that time it is possible to call this routine multiple times for same
	variables or for different variables.
	Changes take effect immediately as the <i>worker</i> resumes execution.
</p>
<p>
	The new value is passed as <strong>BLOB</strong> and is later translated to the 
	appropriate data type via MySQL's internal assignment mechanism.
</p>
<p>
	Execution of this routine only makes sense on an active debugging session, i.e.
	after calling <a href="rdebug_start.html">rdebug_start()</a>.
</p>

<h3>SYNOPSIS</h3>
<p>
<blockquote><pre>rdebug_set_variable(
    in rdebug_variable_name varchar(128),
    in rdebug_variable_value blob
  )
  MODIFIES SQL DATA</pre></blockquote>
</p>
<p>
  Input: 
  <ul>
    <li><strong>rdebug_variable_name</strong>: name of local variable or user defined variable
    	to change. User defined variables are preceded  by <strong>"@"</strong>.
    
	</li>
    <li><strong>rdebug_variable_value</strong>: new value for variable.</li>
  </ul>
</p>


<h3>EXAMPLES</h3>
	<p>
		Watch current variables, modify a variable, and watch the change:
	<blockquote><pre>mysql&gt; call rdebug_watch_variables();
+----------------+--------------------------+-------------------+---------------+----------------+
| routine_schema | routine_name             | variable_name     | variable_type | variable_value |
+----------------+--------------------------+-------------------+---------------+----------------+
| test           | analyze_continent_cities | @avg_count_cities | user_defined  | 18.282608695   |
| test           | analyze_continent_cities | @count_countries  | user_defined  | 46             |
| test           | analyze_continent_cities | current_continent | param         | Europe         |
+----------------+--------------------------+-------------------+---------------+----------------+

mysql&gt; rdebug_set_variable('current_continent', 'Atlantis');

mysql&gt; rdebug_watch_variables();
+----------------+--------------------------+-------------------+---------------+----------------+
| routine_schema | routine_name             | variable_name     | variable_type | variable_value |
+----------------+--------------------------+-------------------+---------------+----------------+
| test           | analyze_continent_cities | @avg_count_cities | user_defined  | 18.282608695   |
| test           | analyze_continent_cities | @count_countries  | user_defined  | 46             |
| test           | analyze_continent_cities | current_continent | param         | Atlantis       |
+----------------+--------------------------+-------------------+---------------+----------------+
</pre></blockquote>
The above only shows the <i>debugger's</i> view of the variables. At this point, the <i>worker</i>
is still unaware of the changes since it is still suspended. Once the <i>worker</i> resumes
execution, it updates the value of <strong>current_continent</strong> to <strong>'Atlantis'</strong>.
</p>

<h3>ENVIRONMENT</h3>
MySQL 5.1 or newer

<h3>SEE ALSO</h3>
<a href="rdebug_get_variable.html">rdebug_get_variable()</a>,
<a href="rdebug_watch_variables.html">rdebug_watch_variables()</a>

<h3>AUTHOR</h3>
Shlomi Noach