无法使用D3图表更新图表

Question

I have created one drop down(Account_type) in that drop down the value coming from database. ie:value1,value 2,value3... on the basis of selecting value i want to update my chart .But in my current scenario it will be creating a another chart instead of updating same..Again Again it will creating separate chart

My code here

var svg = d3.select("#"+this.htmlObject).append("svg")
    .attr("width", width + margin.left + margin.right)
    .attr("height", height + margin.top + margin.bottom)
  .append("g")
    .attr("transform", "translate(" + margin.left + "," + margin.top + ")");data.forEach(function(d) {
    d.frequency = +d.frequency;
  });

  x.domain(data.map(function(d) { return d.letter; }));
 y.domain([0, d3.max(data, function(d) { return d.frequency; })]);

  svg.append("g")
      .attr("class", "x axis")
      .attr("transform", "translate(0," + height + ")")
      .call(xAxis);

  svg.append("g")
      .attr("class", "y axis")
      .call(yAxis)
    .append("text")
      .attr("transform", "rotate(-90)")
      .attr("y", -75)
      .attr("dy", ".71em")
      .attr("dx","-18em")
      .style("text-anchor", "end")
      .text("Frequency");

  svg.selectAll(".bar")
      .data(data)
    .enter().append("rect")
      .attr("class", "bar")
      .attr("x", function(d) { return x(d.letter); })
      .attr("width", x.rangeBand())
      .attr("y", function(d) { return y(d.frequency); })
      .attr("height", function(d) { return height - y(d.frequency); });

Could you please tell me How i can achieved this.

Answer 1

删除以前的svg元素，并为其他值创建新的svg元素。