本文介绍了如何使用注释配置的MyBatis指定IN param类型的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
如果我想传递空值,我需要明确告诉MyBatis用于java.util.Date IN参数的db-type。但我找不到这样做的方法。
It seems I need to explicitly tell MyBatis what db-type to use for java.util.Date IN parameters if I want to able to pass null values. But I can't find a way of doing that.
我尝试了以下不同的变种而没有运气:
I tried different variations of following with no luck:
@Select("<script>SELECT ... WHERE ... " +
"<if test='#{dateFrom,jdbcType=TIMESTAMP} != null'>" +
" AND date > #{dateFrom,jdbcType=TIMESTAMP}" +
"</if></script>")
List<MyType> getRecords(@Param("dateFrom") dateFrom)
如何指定参数类型什么时候使用注释?
推荐答案
其他开发者已经就此类问题发表了评论。
Other developers already commented about this kind of problem.
- MyBatis it wont override the JdbcType if i specify the JdbcType in the paramete #139
我引用GitHub评论:
public class StrToIntTypeHandler implements TypeHandler<String> {
@Override
public void setParameter(PreparedStatement ps, int i,
String parameter, JdbcType jdbcType) throws SQLException {
ps.setInt(i, Integer.parseInt(parameter));
}
// other methods are for binding query results.
}
现在,如果您要创建这样的自定义类型处理程序:
So now, if you will create such a custom typehandler:
public class Null2DateTypeHandler implements TypeHandler<Date> {
@Override
public void setParameter(PreparedStatement ps, int i, java.util.Date parameter, JdbcType jdbcType) throws SQLException {
System.err.println(String.format("ps: %s, i: %d, param: %s, type: %s", ps.toString(), i, parameter, jdbcType.toString()));
if (parameter == null) {
ps.setDate(i, null); // ??? I'm not sure. But it works.
} else {
ps.setDate(i, new java.sql.Date(parameter.getTime()));
}
}
}
并且,mapper方:
And, mapper side:
@Select({
"<script>"
, "SELECT * FROM `employees` WHERE `hire_date` "
, " BETWEEN
, " #{dateFrom,typeHandler=*.*.*.Null2DateTypeHandler}"
, " AND"
, " #{dateTo,typeHandler=*.*.*.Null2DateTypeHandler}"
,"</script>"
})
@Results({
@Result(property = "empNo", column = "emp_no"),
@Result(property = "birthDate", column = "birth_date"),
@Result(property = "firstName", column = "first_name"),
@Result(property = "lastName", column = "last_name"),
@Result(property = "gender", column = "gender"),
@Result(property = "hireDate", column = "hire_date")
})
List<Employees> selectBetweenTypeHandler(@Param("dateFrom") Date dateFrom, @Param("dateTo") Date dateTo);
我的记录它看起来工作正常。
My logging, it looks working fine.
DEBUG [main] - ==> Preparing: SELECT * FROM `employees` WHERE `hire_date` BETWEEN ? AND ?
ps: org.apache.ibatis.logging.jdbc.PreparedStatementLogger@369f73a2, i: 1, param: null, type: OTHER
DEBUG [main] - ==> Parameters: null, null
ps: org.apache.ibatis.logging.jdbc.PreparedStatementLogger@369f73a2, i: 2, param: null, type: OTHER
DEBUG [main] - <== Total: 0
这篇关于如何使用注释配置的MyBatis指定IN param类型的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持!