pgsql -- resultType="java.lang.Integer"和resultType="int"

工具：mybatis+pgsql

详见pgsql官方文档

案例 – resultType=“java.lang.Integer”

dao层

Integer selectMaxAge(String sex); 

sql

<select id = "selectMaxAge"  resultType = "java.lang.Integer">
	select  max(age)
	  from  user
     where  sex = #{sex}
</select>

案例 – resultType=“int”

dao层

int count(String sex); 

sql

<select id = "count"  "resultType="int"">
	select  count(1)
	  from  user
     where  sex = #{sex}
</select>