在NamedParameterJDBCTemplate中绑定ORDER BY的参数

Question

我试图在Spring MVC应用程序中使用NamedParameterJdbTemplate.问题是当我包含下面列出的ORDER BY子句之一时,绑定参数似乎不起作用(不进行排序).但是,sql中的列名称的硬编码顺序有效.

ORDER BY column1 
ORDER BY column1 
ORDER BY column1 asc
ORDER BY column1 desc

例如,下面列出的查询不起作用.

    private static final String SEARCH_ALL_BY_SORT_ORDER=
        " select FIRST_NM, MIDDLE_NM, LAST_NM, CUSTOMER_IDENTIFIER,  EMAIL_ADDRESS,  ACCOUNT_ID" +
        " from VIEW " +
        " where CUSTOMER_IDENTIFIER= :customerIdentifier " +
        " and ( REGEXP_LIKE(FIRST_NM, :firstName, 'i') " +
        "       or REGEXP_LIKE(LAST_NM, :lastName, 'i')  " +
        "       or REGEXP_LIKE(EMAIL_ADDRESS, :emailAddress, 'i')  )" +
        " order by :sortColumns";

按列的硬编码顺序的相同查询有效:

    private static final String SEARCH_ALL_BY_SORT_ORDER=
        " select FIRST_NM, MIDDLE_NM, LAST_NM, CUSTOMER_IDENTIFIER,  EMAIL_ADDRESS,  ACCOUNT_ID" +
        " from VIEW " +
        " where CUSTOMER_IDENTIFIER= :customerIdentifier " +
        " and ( REGEXP_LIKE(FIRST_NM, :firstName, 'i') " +
        "       or REGEXP_LIKE(LAST_NM, :lastName, 'i')  " +
        "       or REGEXP_LIKE(EMAIL_ADDRESS, :emailAddress, 'i')  )" +
        " order by LAST_NM";

这是相关的jdbctemplate代码

Map <String, Object> params = new HashMap <String, Object>();
        params.put("customerIdentifier", customerIdentifier);
        params.put("firstName",  searchCriteria );
        params.put("lastName", searchCriteria );
        params.put("emailAddress",searchCriteria);
           // sortBy is COLUMN name
           // sortOrder is either 'asc' or 'desc'
        params.put("sortColumns", sortBy + " " + sortOrder);
           // Using just the column name does not work either
           //params.put("sortColumns", sortBy);

        namedParameterJdbcTemplate.query(SEARCH_ALL_BY_SORT_ORDER, params, new MemberMapper());

Answer 1

只能将值绑定为参数.不是查询本身的一部分.

最后,生成预准备语句,并将参数绑定到预准备语句.准备好的语句的原则是准备查询的执行计划(order by子句是其中的一部分),并且在具有不同参数之后执行一次或多次查询.

如果查询未完成,则无法准备和重用执行计划.因此,对于此部分查询,您需要使用字符串连接动态生成查询,而不是参数.