如何从页面输入SQL查询条件得到后台结果返回前台页面
一、页面：因为查询的表不固定，所以表格需要自助生成（这是利用了“jqGrid”）
注意：难点一、因为从数据库查询的表不同，所有前台页面遍历时的表头格式不固定
难点二、数据库连接源
若是不利用“jqGrid”也可以参考方法2.
方法1.
<body>
<div>
<nobr>
<div>
<form method="POST" action="/management/transactionFlow/informationQuery1">
<div class="row">
<div class="col-md-10">
<textarea name="sql" STYLE="width: 1000px;height: 100px" id="sql"
onfocus="ClearDefault(this)" placeholder="输入查询语句"
onblur="AddDefault(this)">${sql}textarea>
div>
div>
<div class="row">
<div class="col-md-2">
<button type='submit' class="btn btn-primary btn-block" id="sure">确定
button>
div>
<div class="col-md-2">
<button id="back" type="reset" class="btn btn-primary btn-block">重置
button>
div>
<div class="col-md-2">
<p id="message" style="height: 28px" align="center">p>
div>
div>
form>
div>
nobr>
<hr style="background-color: #0c0c0c;height: 1px;width: 2000px;">
<%--引入jqGerid--%>
<div>
<table id="jqGrid">table>
<div id="jqGridPager">div>
div>
<content tag="customJavascript">
<script type="text/ecmascript" src="/plugins/jqGrid-master/js/i18n/grid.locale-cn.js">script>
<script type="text/ecmascript" src="/plugins/jqGrid-master/js/jquery.jqGrid.js">script>
<script src="/plugins/datepicker/bootstrap-datepicker.js">script>
<script src="/plugins/datepicker/locales/bootstrap-datepicker.zh-CN.js">script>
<script type="text/javascript">
//加载的主表（对表格进行遍历
$(document).ready(function () {
// var applicationId = $('#applicationId option:selected').val();
$("#jqGrid").jqGrid({
url:"/management/transactionFlow/informationQuery",
mtype: "POST",
datatype: "json",
postData: {
'sql': function () {
return $('#sql').val().trim();}
},
styleUI: 'Bootstrap',
colModel: [
<c:forEach items="${list3}" var="user" varStatus="status">
{label: '${user}', name: '${user}', autowidth: true, sortable: false},
c:forEach>
],
viewrecords: true,
height: 400,
shrinkToFit: false,
rowNum: 10,
autowidth: true,
pager: "#jqGridPager",
page: 1
}).trigger("reloadGrid");
return false;
var len = $("#jqGrid").getGridParam("width");
// $("#jqGrid").setGridParam().hideCol("id");
$("#jqGrid").setGridWidth(len);
});
//点击重置按钮
$("#back").click(function () {
$("#sql").empty();
});
script>
content>
div>
body>方法2.动态生成表格，但是分页还需自己在写一下
参考网址：https://q.cnblogs.com/q/73869/
var table = "";
table += "" + "" + " ";
for (var i = 0; i < date.length; i++) {
table += "" + date[i] + " ";
}
table += "";
table += "" + department[j] + " ";
for (var n = 0; n < date.length; n++) {
table += "" + SeriesStr[0].data[n] + " ";
}
}
table += " ";
table += "
";
$("#Exceltable").html(table);
效果：
二、controller
1）查询表头
@RequestMapping(value = "transactionFlow/informationQuery1", method = RequestMethod.POST)
public String informationQuery1(@ModelAttribute("form") @RequestParam (value = "sql") String sql, Model model) {
List<String> list3 = new LinkedList<>();
String query1 = customerLedgersService.query(sql);
Map map = new HashMap();
if (query1 != null) {
String[] key = query1.split(";");
for (int i = 0, len = key.length; i < len; i++) {
list3.add(key[i]);
}
model.addAttribute("sql", sql);
model.addAttribute("list3", list3);
return "/complement/informationQuery";
} else {
model.addAttribute("sql", sql);
return "/complement/informationQuery";
}
}2）查询分页信息
@RequestMapping(value = "transactionFlow/informationQuery", method = RequestMethod.POST)
@ResponseBody
public GridData informationQuery(@RequestParam(value = "sql", required = false) String sql,
@RequestParam(value = "page", required = false) Integer page,
@RequestParam(value = "rows", required = false) Integer rows
) {
List list7 = new LinkedList<>();
String queryValue = null;
String records1 = customerLedgersService.query1(sql);
int records = Integer.parseInt(records1);
GridData result = new GridData();
String listTotal = customerLedgersService.query2(sql, page, rows);
String query2 = null;
List<String> list6 = new ArrayList<>();
List<String> list5 = new ArrayList();
if (listTotal != null) {
String[] keyq3 = listTotal.split("%");
for (int i = 0, len = keyq3.length; i < len; i++) {
list6.add(keyq3[i]);
}
for (int m = 0; m < list6.size(); m++) {
queryValue = list6.get(m);
String[] value = queryValue.split(";");
List<String> list = Arrays.asList(value);
ListIterator<String> li = list.listIterator();
while (li.hasNext()) {
Object obj = li.next();
if (obj.equals("0E-8")) {
li.set("0.00000000");
}
if (obj.equals("null")) {
li.set("");
}
}
list7.add(list);
}
}
long totaPage = records % rows == 0 ? records / rows : records / rows + 1;
result.setPage(page);
result.setRecords(records);
result.setTotal((int) totaPage);
if (list7 != null) {
result.getRows().addAll(list7);
}
return result;
}
三、dao层（利用了JDBC原理）
需要考虑的是数据库连接问题
@Repository
public class QueryDaoImpl implements QueryDao {
private static Logger logger = LoggerFactory.getLogger(QueryDaoImpl.class);
@Override
public String selectSql(String sql) {
DataSource ds = null;
Connection conn = null;
PreparedStatement pstmt = null;
ResultSet rs = null;
StringBuffer sb = new StringBuffer();
int index = 1;
//1 获得连接
try {
if(sql == null){
return null;
}
InitialContext initialContext = new InitialContext();
ds = (DataSource) initialContext.lookup("jdbc/account-structure");
if (ds != null) {
conn = ds.getConnection();
}
if(!sql.contains(";")){
sql=sql+";";
}
if(!sql.contains("limit") && !sql.contains("LIMIT")){
if(sql.contains(";")){
sql = sql.replaceAll(";", "");
}
sql = sql + " limit 0, 1;";
}
pstmt = conn.prepareStatement(sql);
rs = pstmt.executeQuery();
ListString, Object>> values = new ArrayList<>();
ResultSetMetaData rsmd = rs.getMetaData();
LinkedHashMap<String, Object> map = null;
while (rs.next()) {
//把一条记录放入Map中
map = new LinkedHashMap<String, Object>();
for (int i = 0; i < rsmd.getColumnCount(); i++) {
String columnLabel = rsmd.getColumnLabel(i + 1);
Object value = rs.getObject(i + 1);
map.put(columnLabel, value);
}
values.add(map);
}
if (values.size() > 0) {
for (Map<String, Object> m : values) {
Set<String> set = m.keySet();
for (String s : set) {
sb.append(s + ";");
}
}
}
return sb.toString();
} catch (Exception e) {
e.printStackTrace();
} finally {
//6关闭资源
// JDBCUtils.close(conn, pstmt, rs);
try {
conn.close();
} catch (SQLException e) {
e.printStackTrace();
try {
pstmt.close();
} catch (SQLException e1) {
e1.printStackTrace();
}
try {
rs.close();
} catch (SQLException e1) {
e1.printStackTrace();
}
}
}
return null;
}
@Override
public String selectSql1(String sql) {
DataSource ds = null;
Connection conn = null;
PreparedStatement pstmt = null;
ResultSet rs = null;
StringBuffer sb = new StringBuffer();
int index = 0;
//1 获得连接
try {
if(sql == null){
return null;
}
InitialContext initialContext = new InitialContext();
ds = (DataSource) initialContext.lookup("jdbc/account-structure");
if (ds != null) {
conn = ds.getConnection();
}
if(!sql.contains(";")){
sql=sql+";";
}
if(!sql.contains("limit") && !sql.contains("LIMIT")){
if(sql.contains(";")){
sql = sql.replaceAll(";", "");
}
sql = sql + " limit 0, 5000;";
}
pstmt = conn.prepareStatement(sql);
rs = pstmt.executeQuery();
ListString, Object>> values = new ArrayList<>();
ResultSetMetaData rsmd = rs.getMetaData();
LinkedHashMap<String, Object> map = null;
while (rs.next()) {
//把一条记录放入Map中
map = new LinkedHashMap<String, Object>();
for (int i = 0; i < rsmd.getColumnCount(); i++) {
String columnLabel = rsmd.getColumnLabel(i + 1);
Object value = rs.getObject(i + 1);
map.put(columnLabel, value);
}
values.add(map);
}
if (values.size() > 0) {
for (Map<String, Object> m : values) {
Set<String> set = m.keySet();
for (String s : set) {
sb.append(s + ";");
}
sb.append("|"+index++);
}
}
return String.valueOf(index);
} catch (Exception e) {
e.printStackTrace();
} finally {
//6关闭资源
// JDBCUtils.close(conn, pstmt, rs);
try {
conn.close();
} catch (SQLException e) {
e.printStackTrace();
try {
pstmt.close();
} catch (SQLException e1) {
e1.printStackTrace();
}
try {
rs.close();
} catch (SQLException e1) {
e1.printStackTrace();
}
}
}
return null;
}
@Override
public String selectSq2(String sql, Integer page, Integer rows) {
DataSource ds = null;
Connection conn = null;
PreparedStatement pstmt = null;
ResultSet rs = null;
StringBuffer sb = new StringBuffer();
StringBuffer sb1 = new StringBuffer();
int index = 1;
//1 获得连接
try {
InitialContext initialContext = new InitialContext();
ds = (DataSource) initialContext.lookup("jdbc/account-structure");
if (ds != null) {
conn = ds.getConnection();
}
String sql1=null;
StringBuffer sql2=null;
if(!sql.contains(";")){
sql=sql+";";
}
sql1=sql.substring(0,sql.length()-1);
sql2=sb1.append(sql1+" "+"limit"+" "+"?"+","+"?;");
pstmt = conn.prepareStatement(sql2.toString());
int startIndex = (page - 1) * rows;
pstmt.setInt(1,startIndex);
pstmt.setInt(2,rows);
rs = pstmt.executeQuery();
ListString, Object>> values = new ArrayList<>();
ResultSetMetaData rsmd = rs.getMetaData();
LinkedHashMap<String, Object> map = null;
while (rs.next()) {
//把一条记录放入Map中
map = new LinkedHashMap<String, Object>();
for (int i = 0; i < rsmd.getColumnCount(); i++) {
String columnLabel = rsmd.getColumnLabel(i + 1);
Object value = rs.getObject(i + 1);
map.put(columnLabel, value);
}
values.add(map);
}
if (values.size() > 0) {
for (Map<String, Object> m : values) {
Set<String> set = m.keySet();
for (String s : set) {
sb.append(m.get(s) + ";");
}
sb.append("%");
}
}
return sb.toString();
} catch (Exception e) {
e.printStackTrace();
} finally {
try {
conn.close();
} catch (SQLException e) {
e.printStackTrace();
try {
pstmt.close();
} catch (SQLException e1) {
e1.printStackTrace();
}
try {
rs.close();
} catch (SQLException e1) {
e1.printStackTrace();
}
}
}
return null;
}
}
查询页面：
输入SQL语句：SELECT * from ledgers_entity where customer_business_id=’180050602775019520’;
查询结果：
