10.31每日总结

SELECT * from sys_user limit 0,2;  --第一页
-- (2 -1) * 2 = 2
SELECT * from sys_user limit 2,2;  --第二页
-- （3-1）* 2 = 4
SELECT * from sys_user limit 4,2;  --第三页
-- 结论： limit第一个参数 = (pageNum - 1) * pageSize

// 分页查询
    //  接口路径：/user/page?pageNum=1&pageSize=10
    // @RequestParam接受
//    limit第一个参数 = (pageNum - 1) * pageSize
    // pageSize
    @GetMapping("/page")
    public Map<String, Object> findPage(@RequestParam Integer pageNum,
                                        @RequestParam Integer pageSize,
                                        @RequestParam String username) {
        pageNum = (pageNum - 1) * pageSize;
        username = "%" + username + "%";
        List<User> data = userMapper.selectPage(pageNum, pageSize, username);
        Integer total = userMapper.selectTotal(username);
        Map<String, Object> res = new HashMap<>();
        res.put("data", data);
        res.put("total", total);
        return res;
    }

<el-pagination
              @size-change="handleSizeChange"
              @current-change="handleCurrentChange"
              :current-page="pageNum"
              :page-sizes="[2, 5, 10, 20]"
              :page-size="pageSize"
              layout="total, sizes, prev, pager, next, jumper"
              :total="total">
          </el-pagination>

    load() {
      fetch("http://localhost:9090/user/page?pageNum="+this.pageNum+"&pageSize=" + this.pageSize + "&username=" + this.username)
          .then(res => res.json()).then(res => {
        console.log(res)
        this.tableData = res.data
        this.total = res.total
      })
    },
    handleSizeChange(pageSize) {
      console.log(pageSize)
      this.pageSize = pageSize
      this.load()
    },
    handleCurrentChange(pageNum) {
      console.log(pageNum)
      this.pageNum = pageNum
      this.load()
    }