我在mapper.xml中执行的SQL语句在navicat中可以执行成功,且返回值是2,可是在idea中执行返回值却是0,求各位大佬解惑
Mapper.xml中的语句:
<select id="selectByName" parameterType="String" resultType="int">
select COUNT(*) from t_user where name = #{name};
</select>
mapper.java中的语句:
public int selectByName(String name);
service中的语句
public int findByName(String name) {
int num = userMapper.selectByName(name);
System.out.println("chachachachachachacha"+num);
return num;
}
controller中的语句
@RequestMapping(value = "/checkName",method = RequestMethod.POST,consumes = "application/json")
@ResponseBody
public Boolean checkName(@RequestBody String name){
System.out.println(name);
int num=userService.findByName(name);
System.out.println("00000000000000000000000000000"+num);
if (num == 0){
return true;
}else{
return false;
}
}
JSP中HTML的语句:
<div class="layui-form-item">
<label for="username" class="layui-form-label">
<span class="x-red">*</span>用户名:
</label>
<div class="layui-input-inline">
<input type="text" id="username" name="name" value="wisdom"
required="" lay-verify="username"
autocomplete="off" class="layui-input">
</div>
<div class="layui-form-mid layui-word-aux">
<span class="x-red" lay-verify="name">*</span>将会成为您唯一的用户名
</div>
</div>
JSP中JS的语句
form.verify({
username:function (value){
var datas=$('#username').val()
var message='';
var url = "${pageContext.request.contextPath}/system/user/checkName"
$.ajax({
url:url,
type:"post",
data:JSON.stringify(datas),//将name传递给controller
dataType:"json",
async:false,//让Ajax执行代码顺序同步
contentType:'application/json;charset=UTF-8',
success:function (data){
if (data==false){
message="用户名已存在,请重新输入!!"
}
}
});
if (message!==''){
return message;
}
结果:
"wisdom"
2021-06-19 15:22:22.868 DEBUG 22452 --- [nio-8888-exec-3] c.wisdom.mapper.UserMapper.selectByName : ==> Preparing: select COUNT(*) from t_user where name = ?;
2021-06-19 15:22:22.869 DEBUG 22452 --- [nio-8888-exec-3] c.wisdom.mapper.UserMapper.selectByName : ==> Parameters: "wisdom"(String)
2021-06-19 15:22:22.870 DEBUG 22452 --- [nio-8888-exec-3] c.wisdom.mapper.UserMapper.selectByName : <== Total: 1
chachachachachachacha0
000000000000000000000000000000