The Black Horse Day11 Business Introduction case

Transactions: A transaction is a logical set of operations that either executes at the same time or does not complete at the same time

Management of transactions: By default, the database automatically manages transactions, which is managed by a single statement that is exclusive of a transaction.

If you need to control the transaction yourself, you can also open/commit/rollback the transaction with the following command

Start transaction

Commit

Rollback

Transaction Management for JDBC:

Conn.setautocommit (FALSE)//set itself to open transaction

Conn.commit ()//COMMIT TRANSACTION

Conn.rollback ()//ROLLBACK TRANSACTION

SavePoint sp=con.setsavepoint ()//Set rollback point

Conn.rollback (SP)//rollback to the specified rollback point

Case:

Database:

Mysql> CREATE TABLE account (    ID int primary key anto_increment,    name varchar, and money    D ouble);

To view the database:

Mysql> SELECT * FROM account;+----+------+-------+| ID | name | Money |+----+------+-------+|  1 | A    |   | |  2 | b    |   |+----+------+-------+

Transationdemo:

Package Cn.itheima.transation;import Java.sql.connection;import Java.sql.preparedstatement;import Java.sql.resultset;import Java.sql.sqlexception;import Java.sql.savepoint;import cn.itheima.utils.JDBCUtils; public class TransationDemo1 {public static void main (string[] args) {Connection con=null; PreparedStatement Ps=null; ResultSet Rs=null; SavePoint save=null;try {con=jdbcutils.getconnection ();//database default is a SQL statement is a transaction, that is, execute an SQL statement is automatically committed, We need to change the default setting for the database to Falsecon.setautocommit (false);p s=con.preparestatement ("Update account set money=money-10 where name= ?"); Ps.setstring (1, "a");p s.executeupdate ();p s=con.preparestatement ("Update account set money= money+10 where name=?");  Ps.setstring (1, "B");p s.executeupdate ();//Set a rollback point, save=con.setsavepoint ();p s=con.preparestatement ("Update Account set money=money-10 where Name=? "); Ps.setstring (1, "a");p s.executeupdate ();p s=con.preparestatement ("Update account set money= money+10 where name=?"); Ps.setstring (1, "B");p s.executeupdate (); int i=1/0;//commit a transaction, from opening a transaction to committingA transaction this is a transaction, these SQL statements are Con.commit () in a transaction;} catch (Exception e) {e.printstacktrace ();//If an exception is thrown, I also commit the transaction try {if (save==null) {//description does not execute to the rollback point throws an exception Con.rollback ();} else{//is not NULL, it rolls back to the set rollback point con.rollback (save); Con.commit ();}} catch (SQLException E1) {//TODO auto-generated catch Blocke1.printstacktrace ();}} Finally{jdbcutils.closeresource (RS, ps, con);}}}

Re-check the database:

We found

Mysql> select * from account;
+----+------+-------+
| ID | name | Money |
+----+------+-------+
| 1 |    A | 90 |
| 2 |   B | 110 |
+----+------+-------+

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The Black Horse Day11 Business Introduction case