JDBC database API comparison instance learning

/* Function: batch process data in the database. 

For example, enter one thousand data records, it is obviously a waste of time to insert a record after each operation, 

such as creating a connection, and then disconnecting and then creating an insert, and. 

Of course, batch processing is not necessarily efficient, but it is a way to solve the problem. Time: 20131003 Author: 

*/public class PiChuLi {public static void main (String [] args) throws SQLException

 {// TODO Auto-generated method stubcreate ();} static void create () throws SQLException

 {Connection conn = null; PreparedStatement ps = null; ResultSet resultset = null;

 try {// 2. establish connection conn = JdbcUtils. getConnection (); 

// 3. create statement String SQL = "insert into user (name, birthday, money) values (?,?,?) "; 

Ps = conn. prepareStatement (SQL, Statement. RETURN_GENERATED_KEYS); 

for (int I = 0; I <1000; I ++) {ps. setString (1, "sdmf" + I);

 ps. setDate (2, new java. SQL. date (System. currentTimeMillis ();

ps. setFloat (3, 345? I =*ps.addbatch({**ps.exe cuteBatch ();}

 finally {JdbcUtils. free (resultset, ps, conn) ;}} 

seek/* function: Get the primary key of the newly inserted information. 

This is one of the APIs used to learn this method time: 20131003 Author: 

*/public class OtherApi {public static void main (String [] args) throws SQLException 

{int id = create (); System. out. println (id) ;}// the primary key static int create () throws SQLException {Connection conn = null;

 PreparedStatement ps = null; ResultSet resultset = null; try {// 2. establish connection conn = JdbcUtils. getConnection (); 

/ 3. create statement String SQL = "insert into user (name, birthday, money) values ('wy', '2017-09-23 ', '20170101')" cuteUpdate ();

 resultset = ps. getGeneratedKeys (); int id = 0; if (resultset. next () {id = resultset. getInt (1);} return id;} finally {JdbcUtils. free (resultset, ps, conn) ;}} 

seek/* function: Page query time of the result set instance that can be rolled: 20131003 Author: */public class ScrollAPIDemo {public static void main (String [] args) throws SQLException {scroll ();} // a scrollable result set instance 

// querying by PAGE static void scroll () throws SQLException {Connection conn = null; Statement st = null; ResultSet resultset = null; try {// 2. establish connection conn = JdbcUtils. getConnection (); // 3. create statement st = conn. createStatement (); 

// 4. execute the statement String SQL = "select id, name, birthday, money from user" using resultset1_st.exe cuteQuery (SQL); resultset. absolute (8); System. out. println (); if (resultset. previous () {System. out. println (resultset. getObject ("id") + "\ t" + resultset. getObject ("name") + "\ t" + resultset. getObject ("birthday") + "\ t" + resultset. getObject ("money") + "\ t ");} // One paging method, however, is less efficient. MySQL itself supports paging. // For MySQL, if paging is set, it is directly written as: 

// select id, name, birthday in the SQL statement, money from user limit 100th, 10 // that is, 10 data records are displayed in the resultset. absolute (100); 

int I = 0; while (resultset. next () & I <10) {I ++; System. out. println (resultset. getObject ("id") + "\ t" + resultset. getObject ("name") + "\ t" + resultset. getObject ("birthday") + "\ t" + resultset. getObject ("money") + "\ t") ;}} finally {JdbcUtils. free (resultset, st, conn) ;}} progress/* function: updatable result set time: 20131003 Author: */public class UpdateKeGengXin {/*** @ param args * @ throws SQLException */public static void main (String [] args) throws SQLException 

{// TODO Auto-generated method stubread ();} // updatable result set, which is updated after query.

 However, you can use static void read () throws SQLException {Connection conn = null; Statement st = null; ResultSet resultset = null;

 try {// 2. establish connection conn = JdbcUtils. getConnection (); 

// 3. create statement st = conn. createStatement (ResultSet. TYPE_SCROLL_SENSITIVE, ResultSet. CONCUR_UPDATABLE);

 // 4.execution sentence resultset1_st.exe cuteQuery ("select id, name, birthday, money from user where id <10");

 // 5. processing result while (resultset. next () {System. out. println (resultset. getObject ("id"); 

System. out. println (resultset. getObject ("name"); System. out. println (resultset. getObject ("birthday");

 System. out. println (resultset. getObject ("money"); String name = resultset. getString ("name"); if ("wangwu ". equals (name) 

{resultset. updateFloat ("money", 123); resultset. updateRow () ;}} finally {JdbcUtils. free (resultset, st, conn) ;}} 

metadata/* function: metadata information of the database time: 20131003 Author: 

*/public class DBMD {// original database information public static void main (String [] args)

 throws SQLException {Connection conn = JdbcUtils. getConnection (); 

DatabaseMetaData dbmd = conn. getMetaData (); System. out. println (dbmd. getDatabaseMajorVersion (); 

// database name System. out. println (dbmd. getDatabaseProductName ();

// database version number System. out. println (dbmd. getDatabaseProductVersion (); 

// whether transaction-type System is supported. out. println (dbmd. supportsTransactions ());}}