请帮助我使用代码点火器控制器的剑道网格样本

我的看法

$("#grid").kendoGrid({
dataSource: {
    transport: {
        read: {
            url: 'schoolC/crud',
            contentType: 'application/json'
        },
        create: {
            url: 'schoolC/crud',
            type: "PUT",
            datatype: 'json'
        },
        update: {
            url: 'schoolC/crud',
            type: "POST",
            datatype: 'json'
        },
        destroy: {
            url: 'schoolC/crud',
            type: "POST",
            datatype: 'json'
        }                                
    },
    error: function(e) {
            alert(e.responseText);
        },
    schema: {
        data: "data",
        id: "school_id",
        model: {
            fields: {
                school_name: { 
                    type: "string",
                    validation: { required: true }
                }
            }
        }
    },
    pageSize: 10
},
height: 400,
batch: false,
scrollable: true,
sortable: true,
filterable: true,
resizable: true,
toolbar: ['create'],
editable: "popup",
pageable: {                            
    numeric: true,
    refresh: true,
    pageSizes: true
}, 
columns: [
    {
        field: "school_name",
        title: "School Name",                                
        width: 100
    },
    { command: ["edit", "destroy"], title: " ", width: "210px" }                            
]

})；

控制器方法

function crud()
{
    header("Content-type: application/json");
    switch($_SERVER["REQUEST_METHOD"])
    {
        case 'GET':
            echo $this->SchoolM->get_allJsonData(); 
        break;
        case 'PUT':
            echo $this->SchoolM->addSchoolInfo(array('school_name'=> mysql_real_escape_string($_POST["school_name"])));
        break;
        case 'POST':
            echo $this->SchoolM->updateSchoolInfo(array('school_name'=> mysql_real_escape_string($_POST["school_name"])), array('school_id'=> mysql_real_escape_string($_POST["school_id"])));
        break;
        case 'DELETE':
            echo $this->SchoolM->deleteSchool(mysql_real_escape_string($_POST["school_id"]));               
        break;
    }
}

模型方法

function get_allJsonData()
{
    $arr = array();
    $this->db->from('school');
    $this->db->order_by("school_name", "asc");
    $query = $this->db->get();
    foreach($query->result_object() as $rows )
    {
        $arr[] = $rows;
    }
    return "{'"data'":" .json_encode($arr). "}";
}
function addSchoolInfo($school_name)
{
    return json_encode($this->db->insert('school',$school_name));
} 
function updateSchoolInfo($school_date, $condition)
{
    return json_encode($this->db->update('school', $school_date, $condition));
}
function deleteSchool($school_id)
{
    $this->db->where_in('school_id',$school_id);
    return json_encode($this->db->delete('school'));
}   

我正在使用codeigniter它读取，但其余的创建更新和删除都不能正常工作。它还添加了许多空行作为每个创建操作中的行大小。pls帮助我