以下是我的程序
import java.sql.*;
public class testDBMS {
/**
* @param args
*/
public static void main(String[] args) throws ClassNotFoundException,
SQLException{
Class.forName( "com.mysql.jdbc.Driver ");
System.out.println( "111111111 ");
String str=new String( "0404210081 ");
// 链接并验证数据库
Connection connection = DriverManager
.getConnection( "jdbc:mysql://localhost/gongyuguanli ", "root ", "0404210081 ");
System.out.println( "22222222222 ");
Statement state=connection.createStatement();
ResultSet result=state.executeQuery( "select xingbie,name from xueshengmingdan "+
"where xuehao = ' "+str+ " ' ");
while (result.next())
System.out.println(result.getString(1)+ " "+result.getString(2));
}
}
运行是抛出异常如下：
111111111
22222222222
Exception in thread "main " com.mysql.jdbc.exceptions.MySQLSyntaxErrorException: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '= '0404210081 ' ' at line 1
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:936)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:2941)
at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:1623)
at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:1715)
at com.mysql.jdbc.Connection.execSQL(Connection.java:3243)
at com.mysql.jdbc.Connection.execSQL(Connection.java:3172)
at com.mysql.jdbc.Statement.executeQuery(Statement.java:1197)
at testDBMS.main(testDBMS.java:17)
请问是为什么啊 ？？？？我搞了一个植物都不行。
------解决方案--------------------
where前面加个空格
------解决方案--------------------
Exception in thread "main " com.mysql.jdbc.exceptions.MySQLSyntaxErrorException: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '= '0404210081 ' ' at line 1
异常信息说的很清楚了，是说你的SQL语句写错了，不符合SQL的语法。
你看一下你的语句：
ResultSet result=state.executeQuery( "select xingbie,name from xueshengmingdan " + "where xuehao = ' "+str+ " ' ");
SQL语句拼起来是select xingbie,name from xueshengmingdanwhere xuehao = '学号 '
是xueshengmingdan和where之间少个空格。上述语句可以改成：
ResultSet result=state.executeQuery( "select xingbie,name from xueshengmingdan where xuehao = ' "+str+ " ' ");
这样就可以了。