最近从JPA切换到Mybatis,使用无XML配置,@Select注解直接写到interface上,发现IN条件的编写相当麻烦。
一般得写成这样:
java
@Select({"<script>",
"SELECT *",
"FROM blog",
"WHERE id IN",
"<foreach item='item' index='index' collection='list'",
"open='(' separator=',' close=')'>",
"#{item}",
"</foreach>",
"</script>"})
List<Blog> selectBlogs(@Param("list") int[] ids);
写的看起来很别扭,原来JPA+Hibernate写HQL就不用额外处理。想着找一下解决方案,一搜确实也有人有同样的痛点。
原来我写的是这样的:
java
@Select(
"select distinct(USER_ID) from SYS_LOGIN_LOG " +
"where USER_ID IN (#{userIds}) " +
"and TENANT_ID = #{tenantId} " +
"and CREATE_TIME between #{startTime} and #{endTime}")
List<Long> selectInTimeRange(
@Param("userIds") long[] userIds, @Param("tenantId") long tenantId,
@Param("startTime") Date startTime, @Param("endTime") Date endTime
);
发现解析失败,google了一下,通过增加一个语法处理器就解决了。
在Mapper基类添加这样的处理器
java
public interface CcBaseMapper<T> extends BaseMapper<T> {
/**
* 解决mybatis in条件写得难看的问题
*/
class InConditionDriver extends XMLLanguageDriver
implements LanguageDriver {
private final Pattern inPattern = Pattern.compile("\\(#\\{(\\w+)\\}\\)");
public SqlSource createSqlSource(Configuration configuration, String script, Class<?> parameterType) {
Matcher matcher = inPattern.matcher(script);
if (matcher.find()) {
script = matcher.replaceAll("(<foreach collection=\"$1\" item=\"__item\" separator=\",\" >#{__item}</foreach>)");
}
script = "<script>" + script + "</script>";
return super.createSqlSource(configuration, script, parameterType);
}
}
然后添加这个处理器即可:
java
@Lang(InConditionDriver.class)
@Select(
"select distinct(USER_ID) from SYS_LOGIN_LOG " +
"where USER_ID IN (#{userIds}) " +
"and TENANT_ID = #{tenantId} " +
"and CREATE_TIME between #{startTime} and #{endTime}")
List<Long> selectInTimeRange(
@Param("userIds") long[] userIds, @Param("tenantId") long tenantId,
@Param("startTime") Date startTime, @Param("endTime") Date endTime
);
这样就不报错了。搞掂