Question

我有servlet -

@WebServlet("/servlet123")
public class servlet123 extends HttpServlet {


    protected void doPost(HttpServletRequest request,
            HttpServletResponse response) throws ServletException, IOException {
                String usrID = "111" ; 
            String strAllAccocuntsSQL = "SELECT * (FROM account, account_person) "
                    + "WHERE (account.accountNum = account_person.accountNum"
                    + "AND account_person.personID=? )ORDER BY account.accountNum;";
            PreparedStatement prepareSQL = connection
                    .prepareStatement(strAllAccocuntsSQL);
                        prepareSQL.setString(1, usrID);   
            ResultSet resultWithAccounts = prepareSQL.executeQuery();
    }

}

我检查所有关于connection的信息并没关系。

当它到达ResultSet resultWithAccounts = prepareSQL.executeQuery();行时，它会抛出异常 -

 com.mysql.jdbc.exceptions.jdbc4.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 'account_person.personID='111' )ORDER BY account.accountNum' at line 1
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
    at java.lang.reflect.Constructor.newInstance(Unknown Source)
    at com.mysql.jdbc.Util.handleNewInstance(Util.java:411)
    at com.mysql.jdbc.Util.getInstance(Util.java:386)
    at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1053)
    at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:4074)
    at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:4006)
    at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2468)
    at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2629)
    at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2719)
    at com.mysql.jdbc.PreparedStatement.executeInternal(PreparedStatement.java:2155)
    at com.mysql.jdbc.PreparedStatement.executeQuery(PreparedStatement.java:2318)

上述2个表的SQL代码是 -

CREATE TABLE  `account_person` (
 `accountNum` INT( 11 ) NOT NULL ,
 `personID` TEXT NOT NULL
)

和

CREATE TABLE  `account` (
 `accountNum` INT( 11 ) NOT NULL ,
 `dateCreated` DATE NOT NULL ,
 `accountName` TEXT,
 `description` TEXT,
 `statusAccount` TEXT,
 `sumOfMoney` INT( 11 ) NOT NULL DEFAULT  '0'
)

prepareSQL中的SQL语句有什么问题？

Answer 1

我怀疑：

+ "WHERE (account.accountNum = account_person.accountNum"
+ "AND account_person.personID=? )ORDER BY account.account

表示您在没有中间空间的情况下连接accountNum和AND。这与错误信息有关。

Answer 2

尝试删除pharentesis并添加空格：

@WebServlet("/servlet123")
public class servlet123 extends HttpServlet {


    protected void doPost(HttpServletRequest request,
            HttpServletResponse response) throws ServletException, IOException {
                String usrID = "111" ; 
            String strAllAccocuntsSQL = "SELECT * FROM account, account_person "
                    + "WHERE account.accountNum = account_person.accountNum "
                    + "AND account_person.personID=? ORDER BY account.accountNum;";
            PreparedStatement prepareSQL = connection
                    .prepareStatement(strAllAccocuntsSQL);
                        prepareSQL.setString(1, usrID);   
            ResultSet resultWithAccounts = prepareSQL.executeQuery();
    }

}

Answer 3

SQL字符串中存在错误。您应该删除围绕FROM部分的括号

String strAllAccocuntsSQL = "SELECT * FROM account, account_person "
                    + "WHERE (account.accountNum = account_person.accountNum"
                    + "AND account_person.personID=? )ORDER BY account.accountNum;";

我也会取消;最后，如果它还没有工作

在servlet中使用executeQuery执行SQL语句

3 个答案: