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Problems with using Integer type queries

Mapper.xml:

Select count (m.id) from hr_push_msg_model as m m.text like'% ${page.keyword}% 'and m.text like' ${page.entity.text}%' And m.title like'% {page.entity.title}% 'and m.state = # {page.entity.state} and m.type = # {page.entity.type}

For example:

And m.state = # {page.entity.state} when the state value is 0

Mybatis defaults to the empty string "", so if a similar scenario like state is worth it, don't add xxxxxexamples = "" to the query. Or or xxx==0.

Code example:

1 、

And m.state = # {page.entity.state}

2 、

And m.state = # {page.entity.state} mybatis to determine the output of bug scenarios encountered by Integer

All users with status 0 need to be found out.

That's what I wrote.

1.mapper:

BaseUser selectUserByStatus (@ parm ("status") Integer status)

There's a zero in here.

2.sql:

SELECT * FROM base_user WHERE status=0

3.xml fragment

Status = # {status}

4. As a result, the sql actually executed

SELECT * FROM base_user

A brief summary:

Test= "status! = null and status! =''" this is used to judge String! In other words, the same situation can happen to numeric types such as Double,BigDecimal.

1. If it is of type Integer, if the value of the variable is 0, that is, num = 0, mybatis will think that the value of num is an empty string when performing num! =''"; skip the judgment directly

So if it is Integer type, you only need to judge! = null.

two。 If the String type needs to be judged to be not equal to 0, you need to write name! = '0'.toString (), otherwise an error will be reported.

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