JDBC three methods to obtain the auto-increment field value of MySQL inserted data

Three methods for obtaining the MySQL auto increment Field Value
It was found in the built-in MySQL docs. The following test program can run:

----------- The statement. getgeneratedkeys () can be obtained only after being inserted first ()
1. Retrieving auto_increment column values using statement. getgeneratedkeys ()
2. Retrieving auto_increment column values using select last_insert_id ()
3. Retrieving auto_increment column values in updatable resultsets

Import java. SQL. connection;
Import java. SQL. drivermanager;
Import java. SQL. resultset;
Import java. SQL. sqlexception;
Import java. SQL. statement;

Public class retrievautoincrementtest {

Public void Init () throws exception {
Statement stmt = NULL;
Resultset rs = NULL;
Connection conn = NULL;
Try {
Class. forname ("com. MySQL. JDBC. Driver ");
Conn = drivermanager. getconnection ("JDBC: mysql: // localhost/test? Autoreconnect = true & useunicode = true & characterencoding = UTF-8 & mysqlencoding = utf8 "," root ","******");
//
// Issue the DDL queries for the table for this example
//
Stmt = conn. createstatement ();
Stmt.exe cuteupdate ("Drop table if exists autoinctutorial ");
Stmt.exe cuteupdate (
"Create table autoinctutorial ("
+ "Prikey int not null auto_increment ,"
+ "Datafield varchar (64), primary key (prikey ))");
} Finally {
If (RS! = NULL) {try {Rs. Close ();} catch (exception e ){}}
If (stmt! = NULL) {try {stmt. Close () ;}catch (exception e ){}}
If (Conn! = NULL) {try {conn. Close () ;}catch (exception e ){}}
}
}
 
Public void test1 () throws exception {
Statement stmt = NULL;
Resultset rs = NULL;
Connection conn = NULL;
Try {
Class. forname ("com. MySQL. JDBC. Driver ");
Conn = drivermanager. getconnection ("JDBC: mysql: // localhost/test? Autoreconnect = true & useunicode = true & characterencoding = UTF-8 & mysqlencoding = utf8 "," root ","******");
//
// Create a statement instance that we can use
// 'Normal' result sets assuming you have
// Connection 'conn' to a MySQL database already
// Available
Stmt = conn. createstatement (Java. SQL. resultset. type_forward_only,
Java. SQL. resultset. concur_updatable );

//
// Insert one row that will generate an auto Increment
// Key in the 'prikey' Field
//
For (INT I = 0; I <10; I ++ ){
Stmt.exe cuteupdate (
"Insert into autoinctutorial (datafield )"
+ "Values ('Can I get the auto increment field? ')",
Statement. return_generated_keys );
//
// Example of using statement. getgeneratedkeys ()
// To retrieve the value of an auto-Increment
// Value
//
Int autoinckeyfromapi =-1;
Rs = stmt. getgeneratedkeys ();
If (Rs. Next ()){
Autoinckeyfromapi = Rs. getint (1 );
} Else {
// Throw an exception from here
}
Rs. Close ();
Rs = NULL;
System. Out. println ("Key returned from getgeneratedkeys ():"
+ Autoinckeyfromapi );
}
} Finally {
If (RS! = NULL) {try {Rs. Close ();} catch (exception e ){}}
If (stmt! = NULL) {try {stmt. Close () ;}catch (exception e ){}}
If (Conn! = NULL) {try {conn. Close () ;}catch (exception e ){}}
}
}
 
Public void Test2 () throws exception {
Statement stmt = NULL;
Resultset rs = NULL;
Connection conn = NULL;
Try {

//
// Create a statement instance that we can use
// 'Normal' result sets.
Class. forname ("com. MySQL. JDBC. Driver ");
Conn = drivermanager. getconnection ("JDBC: mysql: // localhost/test? Autoreconnect = true & useunicode = true & characterencoding = UTF-8 & mysqlencoding = utf8 "," root ","******");

Stmt = conn. createstatement ();
//
// Insert one row that will generate an auto Increment
// Key in the 'prikey' Field
//
For (INT I = 0; I <10; I ++ ){
Stmt.exe cuteupdate (
"Insert into autoinctutorial (datafield )"
+ "Values ('Can I get the auto increment field? ')");
 
//
// Use the MySQL last_insert_id ()
// Function to do the same thing as getgeneratedkeys ()
//
Int autoinckeyfromfunc =-1;
Rs = stmt.exe cutequery ("select last_insert_id ()");
 
If (Rs. Next ()){
Autoinckeyfromfunc = Rs. getint (1 );
} Else {
// Throw an exception from here
}
Rs. Close ();
System. Out. println ("Key returned from" + "'select last_insert_id ()':"
+ Autoinckeyfromfunc );
}
} Finally {
If (RS! = NULL) {try {Rs. Close ();} catch (exception e ){}}
If (stmt! = NULL) {try {stmt. Close () ;}catch (exception e ){}}
If (Conn! = NULL) {try {conn. Close () ;}catch (exception e ){}}
}
}
 
Public void test3 () throws exception {
Statement stmt = NULL;
Resultset rs = NULL;
Connection conn = NULL;
Try {
//
// Create a statement instance that we can use
// 'Normal' result sets as well as an 'updatable'
// One, assuming you have a connection 'conn'
// A MySQL database already available
//

Class. forname ("com. MySQL. JDBC. Driver ");
Conn = drivermanager. getconnection ("JDBC: mysql: // localhost/test? Autoreconnect = true & useunicode = true & characterencoding = UTF-8 & mysqlencoding = utf8 "," root ","******");
Stmt = conn. createstatement (Java. SQL. resultset. type_forward_only,
Java. SQL. resultset. concur_updatable );
For (INT I = 0; I <10; I ++ ){
//
// Example of retrieving an auto increment key
// From an updatable result set
//
Rs = stmt.exe cutequery ("select prikey, datafield"
+ "From autoinctutorial ");
 
Rs. movetoinsertrow ();
Rs. updatestring ("datafield", "auto increment here? ");
Rs. insertrow ();
 
//
// The driver adds rows at the end
//
Rs. Last ();
//
// We shoshould now be on the row we just inserted
//
Int autoinckeyfromrs = Rs. getint ("prikey ");
Rs. Close ();
Rs = NULL;
System. Out. println ("Key returned for inserted row :"
+ Autoinckeyfromrs );
}
} Finally {
If (RS! = NULL) {try {Rs. Close ();} catch (exception e ){}}
If (stmt! = NULL) {try {stmt. Close () ;}catch (exception e ){}}
If (Conn! = NULL) {try {conn. Close () ;}catch (exception e ){}}
}
}
 
/**
* @ Param ARGs
*/
Public static void main (string [] ARGs) throws exception {
Retrievautoincrementtest test = new retrievautoincrementtest ();
Test. INIT ();
Test. test1 ();
Test. Test2 ();
Test. test3 ();
}

}