SQLITE 数据库被锁定在 Java (IDE NetBeans) 中
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SQLITE Database is locked in java (IDE NetBeans)
提问by Rafi Abro
When I perform any action it works in database but suddenly it shows an error of Database is Locked!
当我执行任何操作时，它在数据库中工作，但突然显示数据库已锁定错误！
Suppose this is the actionPerformed on one button:
假设这是一个按钮上的 actionPerformed：
private void jButton6ActionPerformed(java.awt.event.ActionEvent evt) {
//Sahil_Computers.ConnecrDb(); is the database connecting method!
conn = Sahil_Computers.ConnecrDb();
try{
String sql = "insert into dailyExp (Sr,Description,Amount) values (?,?,?)";
pst = conn.prepareStatement(sql);
pst.setString(1, txt_srE.getText());
pst.setString(2, txt_desE.getText());
pst.setString(3, txt_rsE.getText());
pst.execute();
JOptionPane.showMessageDialog(null, "Saved!");
}catch(Exception e){
JOptionPane.showMessageDialog(null, e);
}finally{
try{
rs.close();
pst.close();
}catch(Exception e){
JOptionPane.showMessageDialog(null, e);
}
}
update_table_exp();
}
and then again when I try to perform another action just like:
然后当我尝试执行另一个操作时，就像：
private void jButton4ActionPerformed(java.awt.event.ActionEvent evt) {
conn = Sahil_Computers.ConnecrDb();
String sql = "delete from dailySale where Sr=?";
try{
pst = conn.prepareStatement(sql);
pst.setString(1, txt_sr1.getText());
pst.execute();
JOptionPane.showMessageDialog(null, "Deleted!");
}catch(Exception e){
JOptionPane.showMessageDialog(null, e);
}finally{
try{
rs.close();
pst.close();
}catch(Exception e){
JOptionPane.showMessageDialog(null, e);
}
}
update_table_sale();
}
or action like this one:
或像这样的动作：
private void jButton9ActionPerformed(java.awt.event.ActionEvent evt) {
conn = Sahil_Computers.ConnecrDb();
try{
String sum = null, sub= null;
String subto = null;
int sum1, sub1, subto1;
String sql = "select sum(Debit) from dailySale";
pst=conn.prepareStatement(sql);
rs=pst.executeQuery();
if(rs.next()){
sum = rs.getString("sum(Debit)");
txt_tsale.setText(sum);
}
sql = "select sum(Amount) from dailyExp";
pst=conn.prepareStatement(sql);
rs=pst.executeQuery();
if(rs.next()){
sub = rs.getString("sum(Amount)");
txt_texp.setText(sub);
}
sum1 = Integer.parseInt(sum);
sub1 = Integer.parseInt(sub);
subto1 = sum1 - sub1;
subto = Integer.toString(subto1);
txt_tsub.setText(subto);
}catch(Exception e){
JOptionPane.showMessageDialog(null, e);
}finally{
try{
rs.close();
pst.close();
}catch(Exception e){
JOptionPane.showMessageDialog(null, e);
}}}
Then it shows database is locked!
然后它显示数据库被锁定！
采纳答案by dic19
You must close any open connection before open a new one. You're opening a new connection conn = Sahil_Computers.ConnecrDb();every time a button is pressed but you never close it. Add conn.close();to your finallyblocks.
在打开新连接之前，您必须关闭任何打开的连接。conn = Sahil_Computers.ConnecrDb();每次按下按钮时，您都会打开一个新连接，但您从未关闭它。添加conn.close();到您的finally块。
Some off-topic concern: use PreparedStatement#executeUpdate()instead PreparedStatement#execute()when you need to execute an INSERT/UPDATE/DELETE statement.
一些题外话关注：使用PreparedStatement#executeUpdate()，而不是PreparedStatement#execute()当你需要执行INSERT / UPDATE / DELETE语句。
