最近做了很多动态的查询,尤其是排序,以及一些状态字段,所以就做了一个总的动态查询,以不变应万变,呵呵
ibatis 里面的sql代码:
<select id="getTopics" resultClass="topic" parameterClass="map">
<![CDATA[
select * from p_Topic
]]>
<dynamic prepend=" WHERE ">
<isPropertyAvailable property="authorId">
<isNotNull property="authorId" prepend=" and ">
authorId=#authorId#
</isNotNull>
</isPropertyAvailable>
<isPropertyAvailable property="marketId">
<isNotNull property="marketId" prepend=" and ">
marketId=#marketId#
</isNotNull>
</isPropertyAvailable>
<isPropertyAvailable property="isDelete">
<isNotNull property="isDelete" prepend=" and ">
isDelete=#isDelete#
</isNotNull>
</isPropertyAvailable>
<isPropertyAvailable property="isBest">
<isNotNull property="isBest" prepend=" and ">
isBest=#isBest#
</isNotNull>
</isPropertyAvailable>
<isPropertyAvailable property="statusStr">
<isNotNull property="statusStr" prepend=" and ">
$statusStr$
</isNotNull>
</isPropertyAvailable>
<isPropertyAvailable property="marketIdList">
<isNotNull property="marketIdList" prepend=" and marketId in ">
<iterate property="marketIdList" conjunction="," close=")" open="(">
#marketIdList[]#
</iterate>
</isNotNull>
</isPropertyAvailable>
</dynamic>
<dynamic prepend=" order by ">
<isPropertyAvailable property="orderStr">
<isNotNull property="orderStr">
$orderStr$
</isNotNull>
</isPropertyAvailable>
</dynamic>
<dynamic>
<isPropertyAvailable property="begin">
<isNotNull property="begin">
limit #begin#
</isNotNull>
</isPropertyAvailable>
<isPropertyAvailable property="max" prepend=" , ">
<isNotNull property="max">
#max#
</isNotNull>
</isPropertyAvailable>
</dynamic>
</select>
<select id="getTopicCount" resultClass="java.lang.Long"
parameterClass="map">
<![CDATA[
select count(id) from p_Topic
]]>
<dynamic prepend=" WHERE ">
<isPropertyAvailable property="authorId">
<isNotNull property="authorId" prepend=" and ">
authorId=#authorId#
</isNotNull>
</isPropertyAvailable>
<isPropertyAvailable property="marketId">
<isNotNull property="marketId" prepend=" and ">
marketId=#marketId#
</isNotNull>
</isPropertyAvailable>
<isPropertyAvailable property="isDelete">
<isNotNull property="isDelete" prepend=" and ">
isDelete=#isDelete#
</isNotNull>
</isPropertyAvailable>
<isPropertyAvailable property="isBest">
<isNotNull property="isBest" prepend=" and ">
isBest=#isBest#
</isNotNull>
</isPropertyAvailable>
<isPropertyAvailable property="statusStr">
<isNotNull property="statusStr" prepend=" and ">
$statusStr$
</isNotNull>
</isPropertyAvailable>
<isPropertyAvailable property="marketIdList">
<isNotNull property="marketIdList" prepend=" and ">
<iterate property="marketIdList" conjunction="," close=")" open=" marketId in (">
#marketIdList[]#
</iterate>
</isNotNull>
</isPropertyAvailable>
</dynamic>
</select>
这里需要注意的是:
①#xxx# 代表xxx是属性值,map里面的key或者是你的pojo对象里面的属性,ibatis会自动在它的外面加上引号,表现在sql语句是这样的 where xxx = 'xxx' ;
而$xxxx$ 则是把xxxx作为字符串拼接到你的sql语句中,比如 order by topicId , 如果你不用$来拼接而用#的话,外面就会被加上引号的哦 比如你的语句这样写 ... order by #xxx# (xxx就是你传进来的字符串topicId),ibatis 就会把他翻译成 order by 'topicId' 这样就报错了 ,用$的结果就是这样 order by topicId
②这里的iterate
<isPropertyAvailable property="marketIdList">
<isNotNull property="marketIdList" prepend=" and marketId in ">
<iterate property="marketIdList" conjunction="," close=")" open="(">
#marketIdList[]#
</iterate>
</isNotNull>
</isPropertyAvailable>
注意 iterate 的property属性
,虽然你上面的isNotNull什么的都有这句,但这里一定要写清楚,否则ibatis会找不到你的list的
数据访问层代码:
public List<Topic> getTopics(Map<String, Object> map) {
return getSqlMapClientTemplate().queryForList("getTopics", map);
}
服务层代码:
public List<Topic> getTopicsByMarketIdList(Long authorId,List<Long> marketIdList,
Integer orderby, Integer status, Pagination pagination) {
Map<String, Object> map = new HashMap<String, Object>();
map.put("authorId", authorId);
map.put("isDelete", false);
map.put("marketIdList", marketIdList);
map.put("orderStr", "这里你组装你的order字符串");
map.put("statusStr","这里你组装你的status字符串");
map.put("begin", pagination.getOffset());
map.put("max", pagination.getPageSize());
//这个getTopicCount()方法和getTopics()大体是一致的,所以我的dao里面省略了它
Long total = topicDao.getTopicCount(map);
if (total == 0) {
return new ArrayList<Topic>();
} else {
pagination.setTotal(total);
List<Topic> res = topicDao.getTopics(map);
return res;
}
}
public class Topic extends BaseObject implements Serializable {
/**
*
*/
private static final long serialVersionUID = -851973667810710701L;
private Long id;
private Long authorId;
private String authorName;
private Long marketId;
private String title;
private String tags;
private String content;
private Date pubdate;
private Integer isBest;
private Integer status;
private Integer isDelete;
private Integer clickCount;
private Integer replyCount;
private Date lastReplyTime;
//getter and setter 省略...
}
Pagination代码:
public class Pagination {
/**
* 要查看的页码
*/
private int page;
/**
* 每页显示数
*/
private int pageSize;
/**
* 一共有多少页
*/
private int totalPage;
/**
* 一共有多少条记录
*/
private long total;
/**
* 当前页的记录数
*/
private int size;
/**
* 只需要topxx，不需要页数信息了
*/
private boolean topOnly;
/**
*从第几条记录开始
*/
private int offset;
public void setOffset(int offset) {
this.offset = offset;
}
public Pagination(int page, int pageSize) {
this.page = page;
this.pageSize = pageSize;
}
public Pagination() {
}
public boolean require() {
return pageSize > 0 ? true : false;
}
public int from() {
return page * pageSize;
}
public int to() {
return from() + size;
}
public int getPage() {
return page;
}
public void setPage(int page) {
this.page = page;
}
public int getPageSize() {
return pageSize;
}
public void setPageSize(int pageSize) {
this.pageSize = pageSize;
}
public int getTotalPage() {
return totalPage;
}
public void setTotalPage(int totalPage) {
this.totalPage = totalPage;
}
public long getTotal() {
return total;
}
public void setTotal(long total) {
this.total = total;
if (pageSize > 0) {
this.totalPage = (int) Math.ceil(total / (double) pageSize);
} else {
this.totalPage = 1;
}
if (page >= totalPage) {
page = totalPage - 1;
}
if (page < 0)
page = 0;
if (pageSize > 0) {
if (page < totalPage - 1)
this.size = pageSize;
else
this.size = (int) (total % pageSize);
} else {
this.size = (int) total;
}
offset=page * pageSize;
}
public int getOffset() {
return offset;
}
public int getSize() {
return size;
}
public void setSize(int size) {
this.size = size;
}
public boolean isTopOnly() {
return topOnly;
}
public void setTopOnly(boolean topOnly) {
this.topOnly = topOnly;
}
}
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