Question

SQL 如何让where条件等于一个变量

sql="SELECT b.title FROM phpcms_special_content AS a
LEFT JOIN phpcms_content AS b ON a.contentid = b.contentid
LEFT JOIN phpcms_special AS c ON a.specialid = c.specialid
WHERE b.catid="'.{$CATEGORY[$r[catid]][catid]}.'}
这个where条件应该怎样写 这样写不对

Answer 1

不太理解你的等于一个变量是什么概念，
sql="SELECT b.title FROM phpcms_special_content AS a
LEFT JOIN phpcms_content AS b ON a.contentid = b.contentid
LEFT JOIN phpcms_special AS c ON a.specialid = c.specialid
WHERE b.catid=?"
PreparedStatement pst = con.prepareStatement(sql);
pst.setString(1,变量);
pst.executeQuery();

Answer 2

就是这样写，
拼语句的时候，把变量加进来就可以了。
b.catid=‘" + ？？ + "'"