Using parameterized commands helps guard against SQL injection attacks, in which an attacker "injects" a command into a SQL statement that compromises security on the server.
These can be parameterized (p1, p2) and you can define the parameter variables later on, before using it in a plot command.
这些函数可以用参数(p 1, p2)表示，您可以稍后在plot命令中使用它们之前再定义参数变量。
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Every command class created from the command pattern would write information to the log. This can include the name of the command class or any parameterized information in the pattern.