In Delphi 7, how do I escape a percent sign (%) in the Format function?

问题

I want to do something like this:

SQL.Text := Format('select foo from bar where baz like ''%s%''',[SearchTerm]);

But Format doesn't like that last '%', of course. So how can I escape it? \%? %%?

Or do I have to do this:

SQL.Text := Format('select foo from bar where baz like ''%s''',[SearchTerm+'%']);

?

回答1:

Use another % in the format string:

SQL.Text := Format('select foo from bar where baz like ''%s%%''',[SearchTerm]);

回答2:

%% , IIRC.

回答3:

Obligatory: http://xkcd.com/327/ :-)

Depending on context, your approach might be vulnerable to SQL injection. If the search term comes from user input it would probably be better to use a parameterized query or at least try to sanitize the input.

回答4:

Add 2 percent sign to have 1 single %
Example :

 Format('select foo from bar where baz like ''%%%s%%'',[SearchString])

Gives you

select foo from bar where baz like '%SearchString%'

来源：https://stackoverflow.com/questions/267487/in-delphi-7-how-do-i-escape-a-percent-sign-in-the-format-function