grails查询结果分页的简单实现

最近在使用Idea编写Grails应用程序，Grails的脚手架确实非常方便，写个domain 增删改查一键完成，但是在项目中我们经常希望查询和list页面集成到一起而不必再弄个单独的查询页，另外查询的结果也支持分页与排序，下面是解决方案

 

控制器中的list

def list = {
    params.offset = params.offset ? params.offset : 0
    params.max = params.max ? params.max : 10
    params.sort = params.sort ? params.sort : "id"
    params.order = params.order ? params.order : "DESC"
    params.linkmanName = params.linkmanName ? params.linkmanName : ""
    params.communications = params.communications ? params.communications : ""
    params.address = params.address ? params.address : ""
    //if (params.adminName) {
    def criteria = Linkman.createCriteria()
    def results = criteria {
      and {
        like('linkmanName', '%' + params.linkmanName + '%')
        like('communications', '%' + params.communications + '%')
        like('address', '%' + params.address + '%')
      }
      maxResults(10)
      int _offset = params.offset ? Integer.parseInt(params.offset) : 0
      firstResult(_offset)
      order("${params.sort}", "${params.order}")
    }
    def _totalCount = Linkman.executeQuery("select count(*) as c from Linkman a where a.linkmanName like '%" + params.linkmanName + "%' and a.communications like '%" + params.communications + "%' and a.address like '%" + params.address + "%'")
    render(view: 'list', model: [linkmanInstanceList: results, linkmanInstanceTotal: _totalCount.getAt(0)])
  }

def list = {
    params.offset = params.offset ? params.offset : 0
    params.max = params.max ? params.max : 10
    params.sort = params.sort ? params.sort : "id"
    params.order = params.order ? params.order : "DESC"
    params.linkmanName = params.linkmanName ? params.linkmanName : ""
    params.communications = params.communications ? params.communications : ""
    params.address = params.address ? params.address : ""
    //if (params.adminName) {
    def criteria = Linkman.createCriteria()
    def results = criteria {
      and {
        like('linkmanName', '%' + params.linkmanName + '%')
        like('communications', '%' + params.communications + '%')
        like('address', '%' + params.address + '%')
      }
      maxResults(10)
      int _offset = params.offset ? Integer.parseInt(params.offset) : 0
      firstResult(_offset)
      order("${params.sort}", "${params.order}")
    }
    def _totalCount = Linkman.executeQuery("select count(*) as c from Linkman a where a.linkmanName like '%" + params.linkmanName + "%' and a.communications like '%" + params.communications + "%' and a.address like '%" + params.address + "%'")
    render(view: 'list', model: [linkmanInstanceList: results, linkmanInstanceTotal: _totalCount.getAt(0)])
  }

关于查询在我们这里有3个查询条件，通过criteria 查询结果在Grails1.1文档中就有范例，但是并不能直接得到符合查询条件的结果总数，开始我妄图使用countBy*动态查询器，诸如Linkman.countByLinkmanNameLikeAndCommunicationsLikeAndAddressLike()来做查询，但是从Hibernate输出的SQL语句发现 countBy*动态查询器最多只能支持2个条件（没找到相关说明，仅根据输出的SQL语句判断），所以只能采用别的办法，就是使用executeQuery 手工编写查询语句。

 

 

list页面

<g:form action="list" method="post">
    联系人姓名：<input type="text" name="linkmanName" value="${params.linkmanName}"/>
    通讯工具：<input type="text" name="communications" value="${params.communications}"/>
    单位或住址：<input type="text" name="address" value="${params.address}"/>
    <input class="save" type="submit" value="查询"/>
  g:form>
div>
<div class="content">
  <table class="data_line" cellSpacing="1" cellPadding="0" width="100%">
    <tbody>
    <tr><td align="center" bgColor="#ececec">
      <table cellSpacing="1" cellPadding="2" width="98%">
        <tbody><tr>
          <td align="right"><div align="center">
            <table height="28" cellSpacing="0" cellPadding="0" width="100%" border="0">
              <tbody><tr vAlign="middle">
                <td> 联系人列表td><td align="right">当前共有${linkmanInstanceTotal}条记录td>
              tr>tbody>table>div>td>tr>tbody>table>
      <table class="data_tab" cellSpacing="1" cellPadding="2" width="98%">
        <thead class="data_th">
        <tr align="center">
          <td width="40">序号td>
          <g:sortableColumn property="linkmanName" title="联系人姓名" params="${params}"/>
          <g:sortableColumn property="linkmanSex" title="性别" params="${params}"/>
          <g:sortableColumn property="address" title="单位或住址" params="${params}"/>
          <td>关系人td>
          <td width="100">操作td>
        tr>
        thead>
        <tbody class="data_tb">
        <g:if test="${flash.message}">
          <div class="message">${flash.message}div>
        g:if>

        <g:each in="${linkmanInstanceList}" status="i" var="linkmanInstance">
          <tr class="${(i % 2) == 0 ? 'odd' : 'even'}">
            <td align="center">${++i + (params.offset ? Integer.parseInt(params.offset) : 0)}td>
            <td> <g:link action="show" id="${linkmanInstance.id}">${fieldValue(bean: linkmanInstance, field: 'linkmanName')}g:link>td>
            <td> ${fieldValue(bean: linkmanInstance, field: 'linkmanSex')}td>
            <td> ${fieldValue(bean: linkmanInstance, field: 'address')}td>
            <td> <g:link action="show" controller="suspect" id="${linkmanInstance.suspectId}">${fieldValue(bean: linkmanInstance, field: 'suspect')}g:link>td>
            <td>
            <g:if test="${session.loginUser.adminLimits.indexOf('canEdit')>=0}">
              <g:link action="edit" id="${linkmanInstance.id}">修改g:link>
            g:if>
            <g:if test="${session.loginUser.adminLimits.indexOf('canDelete')>=0}">
              <g:link action="delete" id="${linkmanInstance.id}" onclick="return confirm('确定删除？');">删除g:link>
            g:if>
            td>
          tr>
        g:each>
        tbody>table>
      <table cellSpacing="1" cellPadding="2" width="98%">
        <tbody>
        <tr><td align="right">
          <div align="right">
            <table height="28" cellSpacing="0" cellPadding="0"
                    width="100%" border="0">
              <tbody>
              <tr vAlign="middle">
                <div class="paginateButtons">
                  <g:paginate total="${linkmanInstanceTotal}" params="${params}"/>
                div>
              tr>tbody>table>div>td>tr>tbody>table>td>tr>tbody>
  table>

    联系人姓名：
    通讯工具：
    单位或住址：
    
  

联系人列表 当前共有${linkmanInstanceTotal}条记录 ${flash.message} 序号 关系人 操作 ${++i + (params.offset ? Integer.parseInt(params.offset) : 0)}  ${fieldValue(bean: linkmanInstance, field: 'linkmanName')}  ${fieldValue(bean: linkmanInstance, field: 'linkmanSex')}  ${fieldValue(bean: linkmanInstance, field: 'address')}  ${fieldValue(bean: linkmanInstance, field: 'suspect')}   修改 删除

 

页面上要注意的就是 使用 params="${params}" 传递查询、分页、排序参数。