java - spring jdbc中如何使用数组

Question

我正在使用 spring jdbc 。我的sql查询涉及“IN”子句，我动态创建“？”基于输入并传递Spring jdbc模板的查询方法的对象数组。

 public  List<Student> getStudentName(String studentId){
  //studentId contains  number of ids sepeated by comma.
 Object [] params= new Object[]{studentId.split(",")}
  Stream<String>  stream= Arrays.stream(studentId.split(","));

 final String stInClauseParameters= stream.map(studentId -> "?").collect((Collectors.joining(",")));


  StringBuilder sql = new StringBuilder();
  sql.append(" select studentName from Student where  student_id IN ("+stInClauseParameters+")")
  return JdbcTemplate.query(sql.toString(),params, new BeanPropertyRowMapper(Student.class))

  }

错误

Prepared Statement: Input parameter not set, index: 1.; nested exception is java.sql.SQLException: JZ0SA: Prepared Statement: Input parameter not set, index: 1

如何在spring jdbc查询方法中使用数组？

Answer 1

更简单的方法是使用可以动态处理 in 子句的 NamedParameterJdbcTemplate。

一个例子是

public class StudentDao extends JdbcDaoSupport {


public List<Student> getStudentName(String studentId) {

    List<String> studentIds = Arrays.asList(studentId.split(","));
    String sql = "SELECT studentName FROM Student WHERE student_id IN (:ids)";

    Map<String, List<String>> params = new HashMap<String, List<String>>();
    params.put("ids", studentIds);

    NamedParameterJdbcTemplate template = new    NamedParameterJdbcTemplate(getDataSource());
    return template.query(sql, params, new BeanPropertyRowMapper(Student.class));
}

}