Layui implements sample code for multi-condition query

<form class="layui-form" action="">
		<div class="layui-inline">
			<label class="layui-form-label">Grade</label>
			<div class="layui-input-inline">
				<input type="text" id="grade" name="grade" placeholder="Please select grade"
					autocomplete="off" class="layui-input">
			</div>
		</div>
		<div class="layui-inline">
			<label class="layui-form-label">Professional</label>
			<div class="layui-input-inline">
				<select name="majorid" id="majorid">
					<option value="">Please select</option>
				</select>
			</div>
		</div>
		<div class="layui-inline">
			<div class="layui-input-inline">
				<button class="layui-btn" id="searchBtn" lay-submit
					lay-filter="formDemo" data-type="reload" style="margin-left: 15px">
					<i class="layui-icon layui-icon-search"></i> Search </button>
				<button type="reset" class="layui-btn layui-btn-primary">Reset</button>
			</div>
		</div>
	</form>

//Grade displayed in calendar var laydate = layui.laydate;
	laydate.render({
		elem : '#grade', //Specify element type : 'year'
	});

	//Get the drop-down box professional $.ajax({
		url : '../../MajorFindAllServlet?deptid=5',
		dataType : 'json',
		data : {
			'state' : 0
		}, //Query all institution types with normal status type : 'post',
		success : function(data) {
			$.each(data, function(index, item) {
				$('#majorid').append(
						new Option(item.majorname, item.majorid)); // Add elements to the drop-down menu });
			layui.form.render("select");
		}
	});

layui.use(['table', 'laydate', 'form' ], function() {...}

//Generate table var table = layui.table;
	table.render({
		elem : '#table',
		url : '../../ClassesFindByPageServlet',
		toolbar : '#toolbarDemo',
		title: 'Class table', //Export file name page: {
			layout:['count','prev','page','next', 'skip']
		}, //Open paging id: 'tableAll',
		where : {
			majorid: '',
			grade : ''
		},
		request : {
			'limitName' : 'pageSize' //Change the default field of the number of entries per page to pageSize
		},
		cellMinWidth : 80, //Globally define the minimum width of regular cells, LayUI 2.2.1 added cols : [ [ {
			type : 'checkbox',
			fixed : 'left'
		}, {
			field : 'classid',
			title: 'Class number'
		}, {
			field : 'classname',
			title: 'Class name'
		}, {
			field : 'deptname',
			title : 'Department Name'
		}, {
			field : 'majorname',
			title : 'Professional name'
		}, {
			field : 'grade',
			title: 'Grade',
			sort : true
		}, {
			fixed : 'right',
			title : 'Operation',
			toolbar : '#barDemo'
		} ] ]
	});

//Click the query button to reload the table $('#searchBtn').on('click', function() {
		table.reload('tableAll', {
			method : 'post',
			where : {
				grade : $('#grade').val(),
				majorid : $('#majorid').val()
			},
			page : {
				curr : 1
			}
		});
		return false;
	});