vue+jdbc實現在前端頁面直接執行完整SQL語句

最近客戶提一個需求，需要在系統功能中增加一個頁面，可以直接執行sql語句。

實現這個功能有三個難點：

1.查詢語句中查詢的table不確定，前端展示的時候表頭也就不是固定的

2.通過jdbc執行sql語句，在執行查詢語句的時候需要返回兩個數據，一個是查詢結果，一個是查詢結果里的所有字段的集合（前端展示時的表頭）

3.查詢結果需要分頁展示，考慮了一下，決定使用在sql里實現分頁的功能

具體代碼如下：

<template>
    <div class="app-container" style="text-align: -webkit-center;">
      <el-card style="width: 98%; height: 593px">
        <el-row :gutter="20">
          <el-form :inline="true" style="text-align:-webkit-left;">
            <el-form-item label="SQL:  ">
              <el-input v-model="sqls" placeholder="請輸入sql" clearable size="small"></el-input>
            </el-form-item>
            <el-form-item>
              <el-button type="primary" @click="getSql1()" size="mini" >執行</el-button>
            </el-form-item>
            <el-form-item label="返回信息:">
              <el-input v-model="msgs" size="small"></el-input>
            </el-form-item>
          </el-form>
        </el-row>

        <el-table
          :data="tableData1"
          border
          loading
          height="320"
          highlight-current-row>

          <el-table-column  v-for="item in tableData"
                            :label="item"
                            :property="item"
                            :key = "item"
                            width="160">
          </el-table-column>
        </el-table>

        <el-pagination style="float: right"
          @size-change="sizeChangeHandle"
          @current-change="currentChangeHandle"
          :current-page="pageIndex"
          :page-sizes="[10, 20, 50, 100]"
          :page-size="pageSize"
          :total="totalPage"
          layout="total, sizes, prev, pager, next, jumper">
        </el-pagination>
      </el-card>
    </div>
</template>

<script>
  import { getSqlRes} from '@/api/platform/crds/companycreditinfo/webSql'
  import {matchRating} from "../../../api/platform/crds/debt/runRating";
  import {remote} from '@/api/admin/dict.js'
    export default {
        name: "index",
      data(){
          return{
            pageIndex: 1,
            pageSize: 10,
            totalPage: 0,
            sqls:undefined,
            tableData:[],
            tableData1:[],
            msgs:"",
            loading: true,
          }
      },
      components :{
      },
      created() {
      },
      methods:{
        sizeChangeHandle(val) {
          this.pageSize = val
          this.pageIndex = 1
          this.getSql()
        },
        currentChangeHandle(val) {
          this.pageIndex = val
          this.getSql()
        },
        getSql() {
          getSqlRes({sql:this.sqls,current: this.pageIndex,
            size: this.pageSize}).then(response => {
            if (response && response.data.code === 0) {
              this.msgs = response.data.data.msg
              this.tableData = response.data.data.table
              this.tableData1 = response.data.data.data
              this.totalPage = response.data.data.totalPage

            } else {
              this.msgs = response.data.data.msg
              this.tableData=[]
              this.tableData1 = []
              this.totalPage = 0
            }
          })
        },
        getSql1() {
          getSqlRes({sql:this.sqls,current: 1,
            size: 10}).then(response => {
            if (response && response.data.code === 0) {
              this.msgs = response.data.data.msg
              this.tableData = response.data.data.table
              this.tableData1 = response.data.data.data
              this.totalPage = response.data.data.totalPage
              this.pageIndex = 1
              this.pageSize = 10

            } else {
              this.msgs = response.data.data.msg
              this.tableData=[]
              this.tableData1 = []
              this.pageSize = 0
            }
          })
        },
      }
    }
</script>

后台代碼：

public class SqlUtil {

    public static R run(Map<String,String> map) {

        String msg = "error";
        String sql = map.get("sql").trim();
        String current = map.get("current");
        int cur = Integer.parseInt(current);
        String size = map.get("size");
        int si= Integer.parseInt(size);
        int start = si * (cur - 1) + 1;
        int end = si * cur;
        String sHead = "";
        HashMap<String, Object> mapData = new HashMap<String, Object>();
        if(sql != null && sql.length() >=6 ) {
            sHead = sql.substring(0, 6);
        } else {
            mapData.put("msg","請輸入正確的sql語句");
            mapData.put("totalPage",0);
            mapData.put("table","");
            mapData.put("data","");
            return new R<>(mapData);
        }

        Connection conn = null;
        PreparedStatement pstmt = null;
        ResultSet rs = null;

        try {
            Class.forName("oracle.jdbc.driver.OracleDriver");
            String url = map.get("url");
            String user = map.get("username");
            String password = map.get("password");
            conn = DriverManager.getConnection(url, user, password);
            if ("select".equalsIgnoreCase(sHead)) {
                String sqlCount = "select count(*) count from(" + sql +")";
                pstmt = conn.prepareStatement(sqlCount);
                rs = pstmt.executeQuery();
                int totalPage = 0;
                if(rs.next())
                {
                    totalPage=rs.getInt("count");
                }
                sql = "select * from ( select s.*,rownum rn from (" + sql + ")s where rownum <= " + end + ") where rn >= "+start;
                pstmt = conn.prepareStatement(sql);
                rs = pstmt.executeQuery();
                ResultSetMetaData md = rs.getMetaData();
                int columnCount = md.getColumnCount();
                List<Object> lists = new ArrayList<Object>();
                List<Object> list1 = new ArrayList<Object>();
                for(int j = 1; j <= columnCount; j++) {
                    list1.add(md.getColumnName(j));
                }
                while(rs.next()) {
                    HashMap<String, Object> rowData = new HashMap<String, Object>();
                    for (int i = 1; i <= columnCount; i++) {
                        rowData.put(md.getColumnName(i), rs.getObject(i));
                    }

                    lists.add(rowData);
                }
                mapData.put("totalPage",totalPage);
                mapData.put("table",list1);
                mapData.put("data",lists);
                mapData.put("msg",sHead+"執行成功");
                return new R<>(mapData);
            }else {
                pstmt = conn.prepareStatement(sql);
                pstmt.executeUpdate();
                mapData.put("msg",sHead+"執行成功");
                mapData.put("table","");
                mapData.put("data","");
                return new R<>(mapData);
            }
        }catch (ClassNotFoundException e) {
                msg = e.getMessage();
                //System.out.println(msg);
        } catch(Exception  e) {
                msg = e.getMessage();
        }
        finally{
            try{
                if(rs != null){
                    rs.close();
                }
                if(pstmt != null){
                    pstmt.close();
                }
                if(conn != null){
                    conn.close();
                }
            } catch (SQLException e) {
                    msg = e.getMessage();
            }
        }
        mapData.put("table","");
        mapData.put("data","");
        mapData.put("msg",msg);
        return new R<>(mapData);
    }
}