java-programming oracle database txt1

Answer 1

The following are the operations related to interacting with the Oracle database in Java programming:

** 1. Connecting to Oracle database with Java **

1. ** Driver loading **
- To connect to the Oracle database in Java, you first need to load the database driver. Usually,`Class.forName("oracle.jdbc.driver.OracleDriver");` is used to load the Oracle database driver. However, in the newer version of dbdbc, this step may not be necessary because the driver loading can be done automatically.
2. ** Connection established **
- You can use the `DriverManager.getConnection()` method to establish a connection to the Oracle database. For example, the connection string to connect to the local Oracle database (assuming the database instance is named `xe`) might be as follows:
- `String URL = "jdbc:oracle:thin:@localhost:1521:xe";`
- At the same time, you need to provide a username and password, for example:
- `String USERNAME = "xxx";`
- `String PWD = "xxx";`
- Then, establish a connection through `Connection conn = DriverManager.getConnection(Url, USERName, PwD);`.

3. ** Interact with the TMT file and operate the database **
- You can use the class in the `java.io` package, such as `BufferedReader`, to read data from the txt-file. For example:
- `BufferedReader reader = new BufferedReader(new InputStreamReader(new FileInputStream("C:\\Users\\luyh\\Desktop\\test.txt")));`
- You can read the contents of the txt-file line by line, such as `while (reader.ready()){Strings = reader.readLine();}`.
- Then, he inserted the read data into the Oracle database. You can use `Preparedstatement` to construct a SQL insert statement, for example:
- `String sql = "insert into jilu(con) values(?) ";`
- `PreparedStatement st = conn.prepareStatement(sql);`
- `st.setString(1, s);`
- Finally, execute the insert operation `int i = st.executeUpdate();` and judge whether the insert is successful according to the returned result.

4. ** About the data order **
- If you find that the data inserted into the database from the txt-file is not in order, you can solve this problem by adding a column to the database table (such as the `pid` column) and arranging the `pid` column in ascending order. You can also use `sequence` in the database to achieve an auto-increasing value, which helps to process data in a specific order.

5. ** Resources closed **
- After the operation is completed, you need to close the related resources, such as `Results Set`,`Announcement`, and `Connection`. For example:
- If there are `Results Set rst`,`Statement stMt`, and `Connection conn`, you can close them in the `finally` block, like `if (rst!= }}`, and perform a similar closing operation on`stMT`and`conn`.
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