java - JDBCTemplate 传递带/多个参数

Question

事情是这样的...我无法通过以下代码传递以下语句“this”永远不会被打印，因此结果集为 0，但查询似乎是正确的。

查询:

select * from opportunities where title = 1 and (zipcode = 11738 or zipcode = 11720 or zipcode = 11727 or zipcode = 11741 or zipcode = 11742 or zipcode = 11755 or zipcode = 11763 or zipcode = 11776 or zipcode = 11779 or zipcode = 11784 or zipcode = 11953)

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上面的查询确实返回结果。***

代码(只是切换了标题和邮政编码位置，运行代码时仍然会返回0结果)

public Opportunity[] getOpportunitiesBy(String title, String zipcode, double miles) {
    title = ""+Constants.TITLES_MAP.get(title.toLowerCase());
    String[] nearbyZipcodes = getZipcodesWithinRadius(zipcode, miles);
    StringBuilder builder = new StringBuilder();
    builder.append("(zipcode = "+zipcode+" or zipcode = "); 
    for(String otherZips : nearbyZipcodes) {
        builder.append(otherZips+" or zipcode = ");
    }
    String formattedZips = Utilities.replaceLast(builder.toString(), " or zipcode = ", ")");
    System.out.println(title+","+formattedZips);
    List<Opportunity> opportunities = this.jdbcTemplate.query("select * from opportunities where ? and title = ?",
            new Object[] { formattedZips, title}, new RowMapper<Opportunity>() {
                public Opportunity mapRow(ResultSet rs, int rowNum) throws SQLException {
                    Opportunity temp = new Opportunity();
                    System.out.println("this");
                    String[] candidateIds = rs.getString("candidateIds").split(",");
                    temp.setCandidateIds(Utilities.StringToIntArray(candidateIds));
                    temp.setCompany(rs.getString("company"));
                    temp.setId(rs.getLong("id"));
                    temp.setHtml(rs.getString("post_data"));
                    temp.setZipcode(rs.getString("zipcode"));
                    temp.setTitle(rs.getInt("title"));
                    try {
                        temp.setLogoImg(new URI(rs.getString("logo_img")));
                    } catch (Exception e) {
                    }
                    return temp;
                }
            });
    return opportunities.toArray(new Opportunity[opportunities.size()]);
}

初始 println(title+","+formattedZips) 的输出

1,(zipcode = 11738 or zipcode = 11720 or zipcode = 11727 or zipcode = 11741 or zipcode = 11742 or zipcode = 11755 or zipcode = 11763 or zipcode = 11776 or zipcode = 11779 or zipcode = 11784 or zipcode = 11953)

Answer 1

您的设置有两处错误。

首先，您不应该使用串联来创建(部分)查询，其次，这不是参数化查询的工作方式。参数在放入之前会被转义，所以我怀疑查询是否是您所期望的。

SQL 有 in 子句，而不是执行 zipcode 或 zipcode 或 zipcode)，而是在查询中使用单个 in 子句。然而，当你想传递一个数组时，你又遇到了问题。要解决此问题，请使用 NamedParameterJdbcTemplate而不是普通的 JdbcTemplate。然后重写查询以使用命名参数和 in 子句。

public Opportunity[] getOpportunitiesBy(String title, String zipcode, double miles) {
   String sql = "select * from opportunities where title = :title and zipcode in (:zips)";
   title = ""+Constants.TITLES_MAP.get(title.toLowerCase());
   String[] nearbyZipcodes = getZipcodesWithinRadius(zipcode, miles);

   Map<String, Object> params = new HashMap<>();
   params.put("title", nearbyZipcodes);
   params.put("zips", near)

   return this.jdbcTemplate.query(sql, params, new RowMapper<Opportunity>() {
       public Opportunity mapRow(ResultSet rs, int rowNum) throws SQLException {
           Opportunity temp = new Opportunity();
           System.out.println("this");
           String[] candidateIds = rs.getString("candidateIds").split(",");
           temp.setCandidateIds(Utilities.StringToIntArray(candidateIds));
           temp.setCompany(rs.getString("company"));
           temp.setId(rs.getLong("id"));
           temp.setHtml(rs.getString("post_data"));
           temp.setZipcode(rs.getString("zipcode"));
           temp.setTitle(rs.getInt("title"));
           try {
               temp.setLogoImg(new URI(rs.getString("logo_img")));
           } catch (Exception e) {
           }
           return temp;
       });

}

类似的东西应该可以解决问题，但是如果您的 getZipCodesWithinRadius 也使用查询，您甚至可以将其用作 in 子句中的子选择并简单地传递给定的查询，这可能会更容易zipcode 和 miles，这样您就可以通过一个查询一次性获得结果(而不是 2 个查询以及随之而来的所有 jdbc 内容)。