我想进行多重搜索。我在MS Access中有一个带有4个表的数据库。所以我再创建了一个表Index1，其中包含用户将搜索的所有4个表中的字段。（索引/主表的排序） ）。问题是搜索没有显示理想的记录数量，它只显示少数记录。请通过查找我的代码中的错误来启发我。提前谢谢！
我的代码：
//package searchbook;
import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
import java.sql.*;
import java.util.*;
public class SearchBook extends HttpServlet {
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html");
HttpSession session = request.getSession(true);
List booklist = new ArrayList();
Connection con = null;
String url = "jdbc:odbc:Driver={Microsoft Access Driver (*.mdb, *.accdb)};DBQ=" + "C:\\users\\ppreeti\\executive_db.accdb";
String driver = "sun.jdbc.odbc.JdbcOdbcDriver";
String user = "";
String pass = "";
String category = "";
category = request.getParameter("input");
String sqlquery = "select Index1.link_id "
+ "FROM Index1 "
+ " WHERE Index1.index_name LIKE '%" + category + "%' ";
String sqlResult = null;
try {
Class.forName(driver);
con = DriverManager.getConnection(url, user, pass);
try {
Statement st = con.createStatement();
System.out.println("Connection created 1");
ResultSet rs = st.executeQuery(sqlquery);
while (rs.next()) {
sqlResult = rs.getString(1);
}
System.out.println("Result retreived 1");
//System.out.println('"sqlquery"');
} catch (SQLException s) {
System.out.println("SQL statement is not executed! " + s);
}
} catch (Exception e) {
e.printStackTrace();
}
System.out.println("************");
String sqlq = "";
int flag = 0;
/*if(sqlResult.equals("1"))
{
flag=1;
System.out.println("entered if block for section!");
sqlq="select Report.Report_Name,Report.Report_ID,Report.Section_ID,Report.Contact_ID,Report.link_id FROM Report "
+ " where Report.Report_Name LIKE '%"+category+"%' ";
sqlq="select Section.Section_Name , Report.Report_Name , Report.Link, Contact.Contact_Name "
+ "FROM Section , Report , Contact"
+ " WHERE Report.Section_ID=Section.Section_ID and Contact.Contact_ID=Report.Report_ID "
+ "and Section.Section_Name = '"+category+"' ";
} */
if (sqlResult.equals("1")) {
flag = 1;
System.out.println("entered if block for section!");
/*sqlq="select Report.Report_Name,Report.Report_ID,Report.Section_ID,Report.Contact_ID,Report.link_id FROM Report "
+ " where Report.Report_Name LIKE '%"+category+"%' ";*/
sqlq = "select distinct Section.Section_Name , Report.Report_Name , Report.Link, Contact.Contact_Name "
+ "FROM Section , Report , Contact"
+ " WHERE Report.Section_ID=Section.Section_ID and Contact.Contact_ID=Report.Contact_ID and Section.Section_Name LIKE '%" + category + "%' ";
// + "and Section.Section_Name = '"+category+"' ";
}
if (sqlResult.equals("2")) {
flag = 1;
System.out.println("entered if block for report!");
/*sqlq="select Report.Report_Name,Report.Report_ID,Report.Section_ID,Report.Contact_ID,Report.link_id FROM Report "
+ " where Report.Report_Name LIKE '%"+category+"%' ";*/
sqlq = "select distinct Section.Section_Name , Report.Report_Name , Report.Link, Contact.Contact_Name "
+ "FROM Section , Report , Contact"
+ " WHERE Report.Section_ID=Section.Section_ID and Contact.Contact_ID=Report.Contact_ID and Report.Report_Name LIKE '%" + category + "%' ";
// + "and Report.Report_Name = '"+category+"' ";
}
if (sqlResult.equals("3")) {
flag = 1;
System.out.println("entered if block for metrics !");
/*sqlq="select Report.Report_Name,Report.Report_ID,Report.Section_ID,Report.Contact_ID,Report.link_id FROM Report "
+ " where Report.Report_Name LIKE '%"+category+"%' "*/
;
sqlq = "select distinct Section.Section_Name , Report.Report_Name , Report.Link, Contact.Contact_Name "
+ "FROM Section , Report , Contact,Metrics"
+ " WHERE Report.Section_ID=Section.Section_ID and Contact.Contact_ID=Report.Contact_ID and Metrics.Report_ID=Report.Report_ID "
+ "and Metrics.Metric_Name LIKE '%" + category + "%' ";
}
if (sqlResult.equals("4")) {
flag = 1;
System.out.println("entered if block for contact name!");
/*sqlq="select Section.Section_Name , Report.Report_Name , Report.Link, Contact.Contact_Name, Metrics.Metric_Name "
+ "FROM Section , Report , Contact, Metrics"
+ " WHERE Report.Section_ID=Section.Section_ID and Metrics.Report_ID=Report.Report_ID "
+ "and Report.Report_ID IN (SELECT Report.Report_ID FROM Report WHERE "
+ "Contact.Contact_ID=Report.Contact_ID and Contact.Contact_Name LIKE '%"+category+"%' and Metrics.Metric_Segment = 'M') ORDER BY Report_Name ";*/
sqlq = "select distinct Section.Section_Name , Report.Report_Name , Report.Link, Contact.Contact_Name "
+ "FROM Section , Report , Contact"
+ " WHERE Report.Section_ID=Section.Section_ID and Contact.Contact_ID=Report.Contact_ID "
+ "and Contact.Contact_Name LIKE '%" + category + "%' ";
}
if (flag == 1) {
try {
Class.forName(driver);
con = DriverManager.getConnection(url, user, pass);
try {
Statement st = con.createStatement();
System.out.println("Connection created");
ResultSet rs = st.executeQuery(sqlq);
System.out.println("Result retreived for 2nd query ");
while (rs.next()) {
List<String> book = new ArrayList<String>();
String Name = rs.getString("Section_Name");
String reportName = rs.getString("Report_Name");
String link = rs.getString("Link");
String contactName = rs.getString("Contact_Name");
/* String metricName=rs.getString("Metric_Name");*/
//String reportId=rs.getString("Report_ID");
book.add(Name);
book.add(reportName);
book.add(link);
book.add(contactName);
/* book.add(metricName);*/
//book.add(reportId);
/* book.add(ind_id);
book.add(ind_name);*/
booklist.add(book);
}
} catch (SQLException s) {
s.printStackTrace();
System.out.println("SQL statement is not executed in 2nd query! " + s);
}
} catch (Exception e) {
e.printStackTrace();
}
}
System.out.println("And it came here lastly !");
request.setAttribute("booklist", booklist);
RequestDispatcher dispatcher = getServletContext().getRequestDispatcher("/searchbook.jsp");
dispatcher.forward(request, response);
System.out.println("***************************************************************************************");
}
}
答案 0 :(得分：1)
再次检查你的逻辑。在这个循环中
while (rs.next()) {
sqlResult = rs.getString(1);
}
循环遍历第一个ResultSet，重复分配
sqlResult = rs.getString(1);
然后对它执行任何操作，直到您到达while循环的末尾，然后继续使用第一个查询提取的最后一行执行其他操作。
答案 1 :(得分：0)
访问工作不同。使用“*”代替“％”等。