Simple test of JDBC connection MySQL database in Java

I. Reference Library

Maven Library: mysql:mysql-connector-java:6.0.6

Second, the SDK environment

JAVA JDK10

Third, the test code

　　

 PackageCom.mysql.mysqlconnector;ImportJava.sql.*; Public classDbmain { Public Static voidMain (string[] args)throwsclassnotfoundexception {System.out.println ("Data Base connection test:");        Connection Connection; var driver= "Com.mysql.cj.jdbc.Driver"; var URL= "jdbc:mysql://127.0.0.1:3306/testdb?characterencoding=utf8&useunicode=true&usessl=false& Servertimezone=asia/shanghai "///Note that the new requirements must be added servertimezone var user= "Root"; var password= "Password"; Try{class.forname (driver); var conn=drivermanager.getconnection (URL, user, password); if(!conn.isclosed ()) System.out.println (String.Format ("Conection to%s successfully.", url)); //statement Executing SQL that cannot use parametersStatement Statement =conn.createstatement (); ResultSet ResultSet= Statement.executequery ("SELECT * FROM student WHERE rowid<999"); ResultSetMetaData MD=Resultset.getmetadata (); var columnCount=Md.getcolumncount ();  for(var i = 1; I <= columnCount; i++) {//Note the starting numberSystem.out.println ("---------------------"); System.out.print (Md.getcolumnclassname (i)+ "\ T");//java.lang.StringSystem.out.print (Md.getcolumndisplaysize (i) + "T");//255System.out.print (Md.getcolumnname (i) + "T");//nameSystem.out.print (Md.getcolumntype (i) + "T");// ASystem.out.print (Md.getcolumntypename (i) + "T");//VARCHARSystem.out.println (Md.getcolumnclassname (i) + "T");//java.lang.String            }             while(Resultset.next ()) { for(var i = 1; I <= columnCount; i++) {System.out.print (Resultset.getobject (i)); System.out.print ("\ T");            } System.out.println ();            } statement.close (); //preparestatementvar preparestatement = conn.preparestatement ("SELECT * from student WHERE rowid<?"); Preparestatement.setint (1, 999);//note here that the columnindex in JDBC is starting from 1. ResultSet results =Preparestatement.executequery ();  while(Results.next ()) {var rowId= Results.getint (1);//note here that the columnindex in JDBC is starting from 1. var name = results.getstring (2); var age= Results.getint (3); System.out.println (RowId+ "\ T" + name + "\ T" +Age );            } preparestatement.close (); //Insertvar insertpreparestatement = conn.preparestatement ("INSERT into student (name,age) VALUES (?,?)", Statement.return_generated_keys); Insertpreparestatement.setstring (1, "Sindrol"); Insertpreparestatement.setint (2, 28); if(Insertpreparestatement.executeupdate () > 0) {ResultSet GK=Insertpreparestatement.getgeneratedkeys (); if(Gk.next ()) System.out.println ("Insert into success. Primary key RowId = "+ Gk.getint (" Generated_key "));            } insertpreparestatement.close (); //Batch commit.Conn.setautocommit (false);//Stop Auto-commit first. var batchpreparestatement = conn.preparestatement ("INSERT into student (name,age) VALUES (?,?)", Statement.return_generated_keys);  for(inti = 0; I < 5; i++) {batchpreparestatement.setstring (1, "Lingling_" +i); Batchpreparestatement.setint (2, (20 +i));            Batchpreparestatement.addbatch (); }            Try{var intarrs=Batchpreparestatement.executebatch ();  for(Var eff:intarrs) System.out.println ("EFF:" +eff); Conn.commit ();
Batchpreparestatement.clearbatch ();//After submission, empty batch. var keys=Batchpreparestatement.getgeneratedkeys ();  while(Keys.next ()) {intRowId = Keys.getint ("Generated_key"); System.out.println ("rowID:" +rowId); }            } Catch(Exception ex) {System.out.println ("Commit failed and would rollback:" +ex.getmessage ());            Conn.rollback (); }finally{batchpreparestatement.close (); }            if(!conn.isclosed ()) conn.close (); } Catch(Exception ex) {System.out.println ("SQL Operation exception:" +ex.getmessage ()); }    }}

Four, the Operation effect

"C:\Program Files\java\jdk-10\bin\java"-javaagent:d:\applicaton\devtools\jetbrains\intellijidea\lib\idea_rt.jar =33464:d:\applicaton\devtools\jetbrains\intellijidea\bin-dfile.encoding=utf-8-classpath D:\Project\JavaProject\ Javademo\out\production\javademo; C:\Users\yungoal\.m2\repository\com\alibaba\fastjson\1.2.16\fastjson-1.2.16.jar; C:\Users\yungoal\.m2\repository\mysql\mysql-connector-java\6.0.6\mysql-connector-java-6.0.6. Jar Com.mysql.mysqlconnector.DbMainData Base Connection test:conection to Jdbc:mysql://127.0.0.1:3306/testdb?characterencoding=utf8&useunicode=true&usessl=false&servertimezone=asia/ Shanghai successfully.---------------------Java.lang.IntegerROWID 4INT Java.lang.Integer---------------------java.lang.String255 name 12VARCHAR java.lang.String---------------------Java.lang.IntegerAge 4INT Java.lang.Integer1 Songxingzhu 2 wanghaixing 3 Sindrol 4 Sindrol 5 Sindrol 28 6 Sindrol 7 Sindrol 8 Sindrol 9 lingling_0 lingling_1 Lin Gling_2 lingling_3 lingling_4 1 songxingzhu 272 wanghaixing 283 Sind     Rol 284 Sindrol 285 sindrol 286 sindrol 287 Sindrol 288 Sindrol 289 Lingling_0 2010 Lingling_1 2111 lingling_2 2212 lingling_3 2313 lingling_4 24Insert into success. Primary KEY RowId=14eff:1eff:1eff:1eff:1eff:1rowID:15rowID:16rowID:17rowID:18rowID:19Process finished with exit code0

　　

Simple test of JDBC connection MySQL database in Java