el-table,列表合并,根据名称列名称相同的品名讲其它列值相同的进行合并,并且不能垮品名合并

如图

用到el-table合并行的方法合并

tableSpanMethod({ row, column, rowIndex, columnIndex }) {
  if (column.property === "materielName") {
    //合并商品名
    const _row = this.spanArr[rowIndex];
    const _col = _row > 0 ? 1 : 0;
    return {
      rowspan: _row,
      colspan: _col,
    };
  }
  // 其它列根据商品名进行合并
  if (column.property === "pieceUnit" || column.property === "pieceNum") {
    const _row = this.spanNewArr[rowIndex] ? this.spanNewArr[rowIndex] : 0;
    return {
      rowspan: _row,
      colspan: _row > 0 ? 1 : 0,
    };
  }
},

   // 获取合并行
    getSpanArr(data) {
      this.spanArr = []; //第2列合并
      let pos = 0; //index

      for (let i = 0; i < data.length; i++) {
        1;
        if (i === 0) {
          // 如果是第一条记录（即索引是0的时候），向数组中加入１
          this.spanArr.push(1); //第二列合并
        } else {
          //第二列合并
          if (data[i].materielName === data[i - 1].materielName) {
            // 如果orgUnitId相等就累加，并且push 0
            this.spanArr[pos] += 1;
            this.spanArr.push(0);
          } else {
            // 不相等push 1
            this.spanArr.push(1);
            pos = i;
          }
        }
      }

      this.spanNewArr = {};
      let tip = 0;
      this.spanArr.forEach((item, index) => {
        for (let i = 0; i < item; i++) {
          const row = data[i + index];
          const lastrow = data[i + index - 1];
          if (i == 0) {
            this.spanNewArr[i + index] = 1;
            tip = i + index;
          } else {
            if (
              row.pieceUnit == lastrow.pieceUnit ||
              row.pieceNum == lastrow.pieceNum
            ) {
              this.spanNewArr[tip] = this.spanNewArr[tip]
                ? this.spanNewArr[tip]
                : 1;
              this.spanNewArr[tip] += 1;
            } else {
              this.spanNewArr[i + index] = 1;
              tip = i + index;
            }
          }
        }
      });

      console.log(this.spanNewArr);
    },

然后在初始值的时候调取方法

   this.getSpanArr(this.tableData);

方法二:一个全新的demo,更简单一些

<template>
  <div>
    <el-table
      :data="tableData"
      :span-method="objectSpanMethod"
      border
      style="width: 100%"
    >
      <el-table-column prop="grade" label="年级"></el-table-column>
      <el-table-column prop="materielName" label="商品名称"></el-table-column>
      <el-table-column prop="score" label="成绩"></el-table-column>
      <el-table-column prop="pieceUnit" label="计件单位"></el-table-column>
    </el-table>
  </div>
</template>

<script>
export default {
  name: "App",
  data() {
    return {
      tableData: [
        {
          grade: "三年二班",
          materielName: "消防水带",
          pieceUnit: "把",
          score: 80,
        },

        {
          grade: "三年二班",
          materielName: "消防水带",
          pieceUnit: "把",
          score: 80,
        },

        {
          grade: "三年一班",
          materielName: "小雷",
          pieceUnit: "把",
          score: 80,
        },

        {
          grade: "三年一班",
          materielName: "小雷",
          pieceUnit: "个",
          score: 80,
        },

        {
          grade: "三年三班",
          materielName: "小雷",
          pieceUnit: "个",
          score: 60,
        },

        {
          grade: "三年三班",
          materielName: "林俊杰",
          pieceUnit: "个",
          score: 60,
        },
        {
          grade: "三年三班",
          materielName: "林俊杰",
          pieceUnit: "个",
          score: 60,
        },
        {
          grade: "三年三班",
          materielName: "林俊杰",
          pieceUnit: "把",
          score: 60,
        },
      ],
      mergeInfo: {
        fieldMap: {},
        fieldList: ["materielName", "score", "pieceUnit"], // 需要合并的列字段
      },
    };
  },
  watch: {
    tableData: {
      immediate: true,
      deep: true,
      handler: function (newVal) {
        this.formatMergeInfo(newVal || []);
      },
    },
  },
  methods: {
    formatMergeInfo(sourceData) {
      // 需要合并的列字段列表
      const mergeFieldList = this.mergeInfo.fieldList;

      const result = mergeFieldList.reduce((prev, prop) => {
        let pos = 0;
        const rowList = [];

        // 记录第一个字段，后面的合并不能超过第一个
        const firstField = mergeFieldList[0];

        sourceData.forEach((item, index) => {
          // 数据为第一行，直接加入新行 1 表示新行
          if (index === 0) {
            rowList.push(1);
          } else {
            // 判断当前行是否与上一行其值相等
            if (item[prop] === sourceData[index - 1][prop]) {
              // 是否第一个，第一次循环时，这里没有值
              if (prev[firstField]) {
                // 再看同样的位置上，第一个字段是否与前一个一样，也一样就是同一组，不一样就是下一组
                if (sourceData[index - 1][firstField] === item[firstField]) {
                  // 相等就加一，即合并这一行
                  rowList[pos] += 1;
                  // 并在这一行占个位置
                  rowList.push(0);
                } else {
                  // 下一组;
                  pos = index;
                  rowList.push(1);
                }
              } else {
                rowList[pos] += 1;
                // 占个位置
                rowList.push(0);
              }
            } else {
              // 不等就开始新的一行，并记录这个位置，用于它后面的行合并到它这里
              pos = index;
              rowList.push(1);
            }
          }
        });
        prev[prop] = rowList;
        return prev;
      }, {});
      console.log(result, "---r");
      this.mergeInfo.fieldMap = result;
    },
    // 默认接受四个值 { 当前行的值, 当前列的值, 行的下标, 列的下标 }
    objectSpanMethod({ column, rowIndex }) {
      const mergeFieldList = this.mergeInfo.fieldList;
      const mergeFieldMap = this.mergeInfo.fieldMap;
      // 判断列的属性v
      if (mergeFieldList.indexOf(column.property) !== -1) {
        // 判断其值是不是为0
        if (mergeFieldMap[column.property][rowIndex]) {
          return [mergeFieldMap[column.property][rowIndex], 1];
        } else {
          // 如果为0则为需要合并的行
          return [0, 0];
        }
      }
    },
  },
};
</script>

<style>
#app {
  font-family: Avenir, Helvetica, Arial, sans-serif;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-align: center;
  color: #2c3e50;
  margin-top: 60px;
}
</style>