示例查询：
SELECT country
FROM data
WHERE city LIKE
(SELECT LEFT ('jakartada',7));
JDBC中的示例：
String sql = " SELECT country FROM data WHERE city LIKE (SELECT LEFT ('?',7)) ";
PreparedStatement ps = koneksi.prepareStatement(sql);
ps.setString(1,city );
ResultSet rs = ps.executeQuery();
为什么这不能正常工作？
最佳答案
预准备语句中没有参数,但代码尝试设置参数.尝试在语句中添加参数.
String sql = " SELECT country FROM data WHERE city LIKE (SELECT LEFT (?,city );
ResultSet rs = ps.executeQuery();
或者尝试删除设置参数的语句：
String sql = " SELECT country FROM data WHERE city LIKE (SELECT LEFT ('jakartada',7)) ";
PreparedStatement ps = koneksi.prepareStatement(sql);
ResultSet rs = ps.executeQuery();