elementui官网的表格单元格合并方法是针对静态数据的，判断是写死的。

rowspan是合并的行数：为1表示不变；为0表示去除该单元格，后面的单元格会向上往这格填； colspan同理

而实际情况表格数据往往是动态的。

现如下图，需要将表格前四列的相同数据项合并。

直接上代码：

<el-table :data="budgetList" border :span-method="objectSpanMethod" highlight-current-row height="100%">
    <el-table-column prop="accName" label="会计科目"></el-table-column>
    <el-table-column prop="unemploy" label="失业保险"></el-table-column>
    <el-table-column prop="employ" label="就业专项"></el-table-column>
    <el-table-column prop="deptOrgName" label="科室"></el-table-column>
    <el-table-column prop="projectName" label="项目"></el-table-column>
    <el-table-column prop="budgetaryAmount" label="金额"></el-table-column>
    <el-table-column prop="moneySource" label="资金渠道" :formatter="columnFormat"></el-table-column>
</el-table>

export default {
    data() {
      return {
        budgetList: [],//表格
        spanArr: [],//二维数组，用于存放单元格合并规则
        position: 0,//用于存储相同项的开始index
      }
    }

methods: {
      //表格
      budgetListInit() {
        let para = {};
        this.$http({
            method: "post",
            url: "...",
            data: para
          })
          .then(res => {
            this.budgetList = res.data || [];
            this.rowspan(0,'accName');
            this.rowspan(1,'unemploy');
            this.rowspan(2,'employ');
            this.rowspan(3,'deptOrgName');
          })
          .catch(err => {});
      },
      
      rowspan(idx, prop) {
        this.spanArr[idx] = [];
        this.position = 0; 
        this.budgetList.forEach((item,index) => {
          if( index === 0){
            this.spanArr[idx].push(1);
            this.position = 0;
          }else{
            if(this.budgetList[index][prop] === this.budgetList[index-1][prop] ){
              this.spanArr[idx][this.position] += 1;//有相同项
              this.spanArr[idx].push(0); // 名称相同后往数组里面加一项0
            }else{
              this.spanArr[idx].push(1);//同列的前后两行单元格不相同
              this.position = index;
            }
          }
        })
      },
      //表格单元格合并
      objectSpanMethod({ row, column, rowIndex, columnIndex }) {
        for(let i = 0; i<4; i++) {
          if(columnIndex === i){
            const _row = this.spanArr[i][rowIndex];
            const _col = _row>0 ? 1 : 0;
            // console.log('第'+rowIndex+'行','第'+i+'列','rowspan:'+_row,'colspan:'+_col)
            return {
              rowspan: _row,
              colspan: _col
            }
          }
        }
      },
    }