Java 结果集数据不完整 评论; ArrayList commentList=null; 试一试{ ConnectionFactory myFactory=ConnectionFactory.getFactory(); 连接conn=myFactory.getConnection(); int i=1;int j=1;int k=1; PreparedStatement pstmt=conn.prepareStatement(“从注释中选择*,其中deletestatus=0,workid=?”; PreparedStatement pstmtLName=conn.prepareStatement(“从LEADER中选择*,其中leaderid=?”; PreparedStatement pstmtname=conn.prepareStatement(“从memberid=?”的成员中选择*”; pstmt.setInt(i++,Integer.parseInt(projid)); 结果集rs=pstmt.executeQuery(); 系统输出打印(rs); commentList=新的ArrayList(); while(rs.next()) { 注释=新注释(); comment.setDetails(rs.getString(“details”); 注释.setDateadded(rs.getTimestamp(“dateadded”); 注释:设置紧急状态(rs.getInt(“紧急状态”); 如果(rs.getInt(“leaderid”)!=0){ 注释.setLeaderid(rs.getInt(“leaderid”); pstmtLName.setInt(j++,rs.getInt(“leaderid”); ResultSet rs2=pstmtLName.executeQuery(); if(rs2.next()){ comment.setFullname(rs2.getString(“firstname”)+“”+rs2.getString(“lastname”); } } 如果(rs.getInt(“成员ID”)!=0){ comment.setMemberid(rs.getInt(“memberid”); 系统输出打印(“在循环中”); pstmtname.setInt(j++,rs.getInt(“memberid”); ResultSet rs3=pstmtname.executeQuery(); if(rs2.next()){ comment.setFullname(rs3.getString(“firstname”)+“”+rs3.getString(“lastname”); } } comment.setProjid(Integer.parseInt(projid)); 添加(注释); } 返回评论列表; }
上面代码的问题是,它只返回结果集的第一个结果 当我删除Java 结果集数据不完整 评论; ArrayList commentList=null; 试一试{ ConnectionFactory myFactory=ConnectionFactory.getFactory(); 连接conn=myFactory.getConnection(); int i=1;int j=1;int k=1; PreparedStatement pstmt=conn.prepareStatement(“从注释中选择*,其中deletestatus=0,workid=?”; PreparedStatement pstmtLName=conn.prepareStatement(“从LEADER中选择*,其中leaderid=?”; PreparedStatement pstmtname=conn.prepareStatement(“从memberid=?”的成员中选择*”; pstmt.setInt(i++,Integer.parseInt(projid)); 结果集rs=pstmt.executeQuery(); 系统输出打印(rs); commentList=新的ArrayList(); while(rs.next()) { 注释=新注释(); comment.setDetails(rs.getString(“details”); 注释.setDateadded(rs.getTimestamp(“dateadded”); 注释:设置紧急状态(rs.getInt(“紧急状态”); 如果(rs.getInt(“leaderid”)!=0){ 注释.setLeaderid(rs.getInt(“leaderid”); pstmtLName.setInt(j++,rs.getInt(“leaderid”); ResultSet rs2=pstmtLName.executeQuery(); if(rs2.next()){ comment.setFullname(rs2.getString(“firstname”)+“”+rs2.getString(“lastname”); } } 如果(rs.getInt(“成员ID”)!=0){ comment.setMemberid(rs.getInt(“memberid”); 系统输出打印(“在循环中”); pstmtname.setInt(j++,rs.getInt(“memberid”); ResultSet rs3=pstmtname.executeQuery(); if(rs2.next()){ comment.setFullname(rs3.getString(“firstname”)+“”+rs3.getString(“lastname”); } } comment.setProjid(Integer.parseInt(projid)); 添加(注释); } 返回评论列表; },java,mysql,jdbc,prepared-statement,resultset,Java,Mysql,Jdbc,Prepared Statement,Resultset,上面代码的问题是,它只返回结果集的第一个结果 当我删除WHILE(RS.NEXT)子句中的IF子句时,它返回了所有需要的结果,但信息不完整,因为我还需要在IF语句中进行查询 如果你们知道确切的问题,请提供帮助,如果你们需要更多信息,请告诉我。谢谢大家! 在这里,问题似乎就在这里 Comment comment; ArrayList<Comment> commentList = null; try{ ConnectionFactory m
WHILE(RS.NEXT)
子句中的IF
子句时,它返回了所有需要的结果,但信息不完整,因为我还需要在IF语句中进行查询
如果你们知道确切的问题,请提供帮助,如果你们需要更多信息,请告诉我。谢谢大家! 在这里,问题似乎就在这里
Comment comment;
ArrayList<Comment> commentList = null;
try{
ConnectionFactory myFactory = ConnectionFactory.getFactory();
Connection conn = myFactory.getConnection();
int i = 1; int j = 1; int k = 1;
PreparedStatement pstmt = conn.prepareStatement("SELECT * FROM COMMENT WHERE deletestatus = 0 and workid = ?");
PreparedStatement pstmtLName = conn.prepareStatement("SELECT * FROM LEADER WHERE leaderid = ?");
PreparedStatement pstmtMName = conn.prepareStatement("SELECT * FROM MEMBER WHERE memberid = ?");
pstmt.setInt(i++, Integer.parseInt(projid));
ResultSet rs = pstmt.executeQuery();
System.out.print(rs);
commentList = new ArrayList<Comment>();
while(rs.next())
{
comment = new Comment();
comment.setDetails(rs.getString("details"));
comment.setDateadded(rs.getTimestamp("dateadded"));
comment.setUrgency(rs.getInt("urgency"));
if(rs.getInt("leaderid") != 0){
comment.setLeaderid(rs.getInt("leaderid"));
pstmtLName.setInt(j++, rs.getInt("leaderid"));
ResultSet rs2 = pstmtLName.executeQuery();
if(rs2.next()){
comment.setFullname(rs2.getString("firstname") +" " + rs2.getString("lastname"));
}
}
if(rs.getInt("memberid") != 0) {
comment.setMemberid(rs.getInt("memberid"));
System.out.print("in the loop");
pstmtMName.setInt(j++, rs.getInt("memberid"));
ResultSet rs3 = pstmtMName.executeQuery();
if(rs2.next()){
comment.setFullname(rs3.getString("firstname") +" " + rs3.getString("lastname"));
}
}
comment.setProjid(Integer.parseInt(projid));
commentList.add(comment);
}
return commentList;
}
对于每个真实条件,j的值都会增加,直到循环迭代。
因此,它增加了prepapred语句的参数索引
应该是
pstmtLName.setInt(j++, rs.getInt("leaderid"));
pstmtMName.setInt(j++, rs.getInt("memberid"));
在这里,问题似乎就在这里
Comment comment;
ArrayList<Comment> commentList = null;
try{
ConnectionFactory myFactory = ConnectionFactory.getFactory();
Connection conn = myFactory.getConnection();
int i = 1; int j = 1; int k = 1;
PreparedStatement pstmt = conn.prepareStatement("SELECT * FROM COMMENT WHERE deletestatus = 0 and workid = ?");
PreparedStatement pstmtLName = conn.prepareStatement("SELECT * FROM LEADER WHERE leaderid = ?");
PreparedStatement pstmtMName = conn.prepareStatement("SELECT * FROM MEMBER WHERE memberid = ?");
pstmt.setInt(i++, Integer.parseInt(projid));
ResultSet rs = pstmt.executeQuery();
System.out.print(rs);
commentList = new ArrayList<Comment>();
while(rs.next())
{
comment = new Comment();
comment.setDetails(rs.getString("details"));
comment.setDateadded(rs.getTimestamp("dateadded"));
comment.setUrgency(rs.getInt("urgency"));
if(rs.getInt("leaderid") != 0){
comment.setLeaderid(rs.getInt("leaderid"));
pstmtLName.setInt(j++, rs.getInt("leaderid"));
ResultSet rs2 = pstmtLName.executeQuery();
if(rs2.next()){
comment.setFullname(rs2.getString("firstname") +" " + rs2.getString("lastname"));
}
}
if(rs.getInt("memberid") != 0) {
comment.setMemberid(rs.getInt("memberid"));
System.out.print("in the loop");
pstmtMName.setInt(j++, rs.getInt("memberid"));
ResultSet rs3 = pstmtMName.executeQuery();
if(rs2.next()){
comment.setFullname(rs3.getString("firstname") +" " + rs3.getString("lastname"));
}
}
comment.setProjid(Integer.parseInt(projid));
commentList.add(comment);
}
return commentList;
}
对于每个真实条件,j的值都会增加,直到循环迭代。
因此,它增加了prepapred语句的参数索引
应该是
pstmtLName.setInt(j++, rs.getInt("leaderid"));
pstmtMName.setInt(j++, rs.getInt("memberid"));
您已经定义了int k
,但没有使用它。我假设您想使用它来设置memberid
参数。
改变
到
它应该是有效的
我想知道当查询中只有一个参数标记时,为什么要使用I++
、j++
和k++
来设置语句的参数值。您应该直接使用pstObject.setInt(1,
。否则,如果rs
获取的记录多于leaderid!=0
和memberid!=0
,它们将导致标记索引增加,例如pstObject.setInt(2,…
,它在查询案例中是无效参数,并引发和SQLException
由于您在while循环中重复使用相同的pstObject
,我建议使用来清除当前参数值。虽然这是可选的,但在某些情况下,立即释放当前参数值使用的资源是有用的。您已经定义了int k
,但没有使用它。我假设您我想用它来设置memberid
参数。
改变
到
它应该是有效的
我想知道当查询中只有一个参数标记时,为什么要使用I++
、j++
和k++
来设置语句的参数值(1,…
。否则,如果rs
获取的记录多于leaderid!=0
和memberid!=0
,它们将导致标记索引的增量,例如pstObject.setInt(2,…
,这是查询案例中的无效参数,并引发和SQLException
由于您在while循环中重复使用相同的pstObject
,因此我建议使用来清除当前参数值。虽然这是可选的,但在某些情况下,立即释放当前参数值所使用的资源是有用的。声明在此上下文中位于错误的位置。此解决方案有效非常好!谢谢!:)声明在此上下文中位于错误的位置。此解决方案非常有效!谢谢!:)为错误声明道歉。我真的不需要那里的k。我希望代码只转到其中一个IF子句,但是,我没有将其设置为IF else,以防数据库中出现任何异常,错误标记会更少。尽管感谢pstObject的建议!我会把它放在那里!谢谢!为错误声明者道歉ion。我真的不需要那里的k。我希望代码只转到其中一个IF子句,但是,我没有将其设置为IF else,只是为了防止数据库中出现任何异常,错误标记会更少。尽管感谢pstObject的建议!我会将其放在那里!谢谢!
pstmtMName.setInt( k++, rs.getInt( "memberid" ) );