嗨，我正在编写一个 spring mvc 休眠注释应用程序，我有 2 个表 "team" 和另一个表 "players"。这里我使用 一个-对一映射和mysql数据库。在玩家表中，我保存玩家记录，如姓名、活跃年份等。“团队” 表包含两个条目teamid(主键)和teamname。 “players” 表包含外键 teamid。在这里，当我尝试删除团队名称而不删除 players 表中的所有引用时，我是获取错误消息
HTTP Status 500 - Request processing failed; nested exception is org.hibernate.exception.ConstraintViolationException: could not execute update query
所以当我删除所有引用时，就没有错误了。那么我如何在删除之前找到所有引用。我有兴趣使用 javascript 显示一条警告消息，警告删除所有引用。我知道如何创建javascript中的简单警报消息，但在这里我必须仅在存在外键引用时才显示警报。我想知道是否有其他方法可以删除外键引用而不影响“玩家” 表。
Team.java
@Entity
@Table(name="Team")
public class AddTeam {
@Id
@Column(name="teamId")
private Integer teamId;
@Column(name="teamName")
private String teamName;
public Integer getTeamId() {
return teamId;
}
public void setTeamId(Integer teamId) {
this.teamId = teamId;
}
public String getTeamName() {
return teamName;
}
public void setTeamName(String teamName) {
this.teamName = teamName;
}
}
Player.java
@Entity
@Table(name="playerdata")
public class Player implements Serializable {
private static final long serialVersionUID = -723583058586873479L;
/**
*
*/
@Id
@Column(name="playerid")
private Integer playerId;
@Column(name="playername")
private String playerName;
@Column(name="yearsactive")
private Integer yearsActive;
@Column(name="country")
private Integer Country;
@OneToOne
@JoinColumn(name="teamId")
private AddTeam teams;
public Integer getPlayerId(){
return playerId;
}
public void setPlayerId(Integer playerId){
this.playerId=playerId;
}
public String getPlayerName(){
return playerName;
}
public void setPlayerName(String playerName){
this.playerName=playerName;
}
public String getCountry(){
return Country;
}
public void setCountry(String Country){
this.Country=Country;
}
public Integer getyearsActive(){
return yearsActive;
}
public void setyearsActive(Integer yearsActive){
this.yearsActive=yearsActive;
}
public AddTeam getTeams() {
return teams;
}
public void setTeams(AddTeam teams) {
this.teams = teams;
}
}
这是在playerDaoImplementation.java类中使用的查询
@Override
public void deleteResource(int playerid) {
// TODO Auto-generated method stub
sessionfactory.getCurrentSession().createQuery("DELETE FROM Resource WHERE playerid=" +playerid).executeUpdate();
}
AddteamDaoImplementation.java中用于删除的查询
@Override
public void deleteTeams(int teamid) {
// TODO Auto-generated method stub
sessiofactory.getCurrentSession().createQuery("DELETE FROM AddTeam WHERE teamid="+teamid).executeUpdate();
}
PlayerController.java 中的删除函数
@RequestMapping(value="/deletePlayer",method=RequestMethod.GET)
public ModelAndView deletePlayerDetails(@ModelAttribute("command") Player player,
BindingResult result){
playerService.deletePlayer(player.getPlayerId());
Map<String, Object> model = new HashMap<String, Object>();
model.put("playerkey", playerService.listPlayer());
model.put("teamKey", addteamService.listTeams());
return new ModelAndView("EditPlayer",model);
}
团队.jsp
<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
pageEncoding="ISO-8859-1"%>
<%@taglib uri="http://www.springframework.org/tags/form" prefix="form"%>
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>Players Manager</title>
<center>
<h2>Add Team Details</h2>
<form:form method="POST" action="Team.html">
<table>
<tr>
<td><form:label path="teamId">Team ID:</form:label></td>
<td><form:input path="teamId" id="demo" value="${team.teamId}"/></td>
</tr>
<tr>
<td><form:label path="teamName">Team Name:</form:label></td>
<td><form:input path="teamName" value="${team.teamName}"/></td>
</tr>
<tr>
<tr>
<td> </td>
<td><input type="submit" value="SAVE"/></td>
</tr>
</table>
</form:form>
<br/>
<c:if test="${!empty teamKey}">
<table align="center" border="1">
<tr>
<th>Category ID</th>
<th>Category Name</th>
<th>Options</th>
</tr>
<c:forEach items="${teamKey}" var="team">
<tr>
<td><c:out value="${team.teamId}"/></td>
<td><c:out value="${team.teamName}"/></td>
<td align="center"><a href="editTeam.html?teamId=${team.teamId}">Edit</a> |
<a href="deleteTeam.html?teamId=${team.teamId}">Delete</a></td>
</tr>
</c:forEach>
</table>
</c:if>
<h2><a href="updateresource.html">Adding Publication</a></h2>
</center>
</body>
</html>
EditPlayer.jsp
<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
pageEncoding="ISO-8859-1"%>
<%@taglib uri="http://www.springframework.org/tags/form" prefix="form"%>
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>Resource Manager</title>
</head>
<body>
<center>
<h2>Add Players</h2>
<form:form method="POST" action="save.html">
<table>
<tr>
<td><form:label path="playerId">Player Id</form:label></td>
<td><form:input path="playerId" value= "${player.playerId }"/></td>
</tr>
<tr>
<td><form:label path="playerName">Name</form:label></td>
<td><form:input path="playerName" value="${player.playerName }"/></td>
</tr>
<tr>
<td><form:label path="YearsActive">Experience</form:label></td>
<td><form:input path="YearsActive" value="${player.YearsActive }"/></td>
</tr>
<tr>
<td><form:label path="Country">Date of Join</form:label></td>
<td><form:input path="Country" value="${player.Country }"/></td>
</tr>
<tr>
<td>
<form:label path="teams.teamId">Team Name</form:label>
</td>
<td>
<form:select path="teams.teamId" cssStyle="width: 150px;">
<option value="-1">Select a type</option>
<c:forEach items="${teamKey}" var="teams">
<option value="${teams.teamId}">${teams.teamName}</option>
</c:forEach>
</form:select>
</td>
</tr>
<tr>
<tr>
<td colspan="2"><input type="submit"value="Submit"></td>
</tr>
</table>
</form:form>
<br/>
<c:if test="${!empty playerkey}">
<table align="center" border="1">
<tr>
<th>Player ID</th>
<th>Player Name</th>
<th>YearsActive</th>
<th>Country</th>
</tr>
<c:forEach items="${playerkey}" var="player">
<tr>
<td><c:out value="${player.playerId}"/></td>
<td><c:out value="${player.playerName }"/></td>
<td><c:out value="${player.YearsActive}"/></td>
<td><c:out value="${player.Country}"/></td>
<td align="center"><a href="editPlayerDetails.html?playerId=${player.playerId}">Edit</a> | <a href="deletePlayer.html?playerId=${player.playerId}">Delete</a></td>
</tr>
</c:forEach>
</table>
</c:if>
<h2><a href="addTeam.html">Adding Team</a></h2>
</center>
</body>
</html>
请帮忙。 提前致谢
最佳答案
您必须在玩家表中对 teamId 进行选择查询才能找到玩家，并且在数据库中您可以在玩家表中进行级联删除，这样当您删除团队时它就会删除玩家。
关于mysql - 如何在spring hibernate注释中查找mysql中的外键引用，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/24379625/