Question

java的swing开发查询只显示表头没有数据是什么意思

主要代码代码如下：

// 查询
if (e.getSource() == select) {

try{
//this.fireTableStructureChanged();
//this.fireTableDataChanged();
//v.removeAllElements();
Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");
Connection con = DriverManager.getConnection(
"jdbc:sqlserver://localhost:1433; DatabaseName=尚清丽",
"sql", "sql0708");
Statement st = con.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE,ResultSet.CONCUR_READ_ONLY);
String tempSql = "select * from eminformation where employ_number='"+num+"'";
ResultSet rs=st.executeQuery(tempSql);
ResultSetMetaData rsmd=rs.getMetaData();
cols=rsmd.getColumnCount();
//headers=new String[cols];
for(int i=1;i<cols ;i++){

colum.addElement(rsmd.getColumnName(i));
}

if(!rs.next()){
JOptionPane.showMessageDialog(null,"没有相关记录！！");
}
else{
//this.fireTableStructureChanged();
//this.fireTableDataChanged();
rs.beforeFirst();
while (rs.next()){
Vector currow = new Vector();

for(int i=1;i<cols;i++){
currow.addElement(rs.getString(i));

}
rows.addElement(currow);
}
tabel = new JTable(rows, colum);
b4.add(tabel, BorderLayout.CENTER);
tabel.setVisible(true);
tabel.setRowHeight(50);
b4.add(new JScrollPane(tabel), BorderLayout.CENTER);
}

Answer 1

这是你没有数据

if(!rs.next()){
JOptionPane.showMessageDialog(null,"没有相关记录！！");
}
你这段不是实现了?????
有资料你後面有else做读取和添加喔!!!

Answer 2

1.数据库可能连接出错~~2.数据库表中可能没数据

追问

有数据的

Answer 3

断点调试不会吗？