I want display a select box if unity_variable equals true or just the unity if not unity_variable equals false

I ve try this :

<div ng-if=question.unity_variable == true>

     <select>

          <option data-ng-repeat=unit in question.unity>{{unit.value}}</option>

     </select>

</div>

<div ng-if=question.unity_variable ==  false || question.unity_variable == ''>

     {{question.unity}}

</div>

And this :

<div ng-show=question.unity_variable == true ng-hide=question.unity_variable ==  false || question.unity_variable == ''>

     <select>

          <option data-ng-repeat=unit in question.unity>{{unit.value}}</option>

     </select>

</div>

<div ng-show=question.unity_variable ==  false || question.unity_variable == ''>

     {{question.unity}}

</div>

so if i didn't put the ng-show that make for each question a select box with unity or display the twice but not respect the condition...
Please help to find my mistake !

EDIT :

My Json look like this for displaying controls to build a form :

{id: 01,

    questions: [

        {name: confidential data, dbcolumn:confidential data, control: input, default_value: , unity: [{value: mmol/l}, {value: autre}], unity_variable: true, isnull: 0, size:180px, data_type:number, max_length: 3},

        {name: confidential data, dbcolumn:confidential data, control: input, default_value: , unity: , isnull: 1, size:180px, data_type:number, max_length: 2},

        {name: confidential data, dbcolumn:confidential data,control: select, default_value: [{name:Femme, value: Femme}, {name:Homme, value: Homme}], unity: , isnull: 0, size:196px, data_type:string}

        ]

}

My html code is :

<table style=display: inline-block; float: left; max-width: 510px;>

    <tr data-ng-repeat=question in group.questions>

        <td>{{question.name}}</td>

        <td>

            <div ng-switch on=question.control style=display: inline-block;>

                 <div ng-switch-when=input>

                     <input type=text style=width: {{ question.size }}; data-isnull={{question.isnull}} name={{question.dbcolumn}} id={{question.dbcolumn}} placeholder={{question.default_value}} maxlength={{question.max_length}} />

                 </div>

                 <div ng-switch-when=textarea>

                      <textarea style=width: {{ question.size }}; data-isnull={{question.isnull}} name={{question.dbcolumn}} id={{question.dbcolumn}} placeholder={{question.default_value}}></textarea>

                 </div>

                 <div ng-switch-when=checkbox>

                      <input type=checkbox data-isnull={{question.isnull}} name={{question.dbcolumn}} id={{question.dbcolumn}} />{{question.default_value}}

                 </div>

                 <div ng-switch-when=select>

                      <select style=width: {{ question.size }}; data-isnull={{question.isnull}} name={{question.dbcolumn}} id={{question.dbcolumn}}>

                          <option data-ng-repeat=choice in question.default_value value={{choice.value}}>{{choice.name}}</option>

                      </select>

                 </div>

                 <div ng-switch-when=p>

                      <p style=width: {{ question.size }}; data-isnull={{question.isnull}} name={{question.dbcolumn}} id={{question.dbcolumn}}><b>{{question.default_value}}</b></p>

                </div>

                <div ng-switch-default>

                      <!-- default action -->

                </div>

            </div>

        </td>

        <td>

            <div ng-if=question.unity_variable == true>

                 <select>

                      <option data-ng-repeat=unit in question.unity>{{unit.value}}</option>

                 </select>

            </div>

            <div ng-if=question.unity_variable ==  false || question.unity_variable == ''> {{question.unity}} </div>    

       </td>

    </tr>

if i try just the simply code :

<div ng-if=1 == 1>true</div>

<div ng-if=1 == 2>false</div>

The result show me true and false so i ve a syntaxe error