PreparedStatement 模糊匹配 結果卻：Parameter index out of range (1 > number of parameters, which is 0)

數據庫查詢中，咱們是這樣進行模糊匹配的：

select * from user where 1=1  and username like '%林%' limit 0,20

理所固然的，在java代碼中你會這麼寫：

select * from user where 1=1  and username like '%?%' limit 0,20

ps.setString(1, userCondition.getUsername());

若是真這麼寫，你就等着撲街吧：Parameter index out of range (1 > number of parameters, which is 0)

這時候怎麼破？

select * from user where 1=1  and username like ? limit 0,20

ps.setString(1, "%"+userCondition.getUsername()+"%");