java - 在 java 中执行 mysql 行时出错

Question

这是我的代码

String Dillingdoctor = driver.findElement(By.id("txtProviderName")).getAttribute("value"); 
         ResultSet res2 = st.executeQuery("SELECT user_name FROM user where person_name= "+Dillingdoctor+" ");
         res2.next();
         String Billing_Doctor = res2.getString(1);
         System.out.println(Billing_Doctor);

我有这个错误:

Exception in thread "main"

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 'Samiee' at line 1

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:407)
        at com.mysql.jdbc.Util.getInstance(Util.java:382)
        at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1052)
        at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3593)
        at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3525)
        at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:1986)
        at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2140)
        at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2620)
        at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2570)
        at com.mysql.jdbc.StatementImpl.executeQuery(StatementImpl.java:1474)
        at login.Verification.main(Verification.java:168)

请问是什么原因？

Answer 1

将您的 SQL 行更改为以下，您缺少 ' 字符...

SELECT user_name FROM user where person_name= '"+Dillingdoctor+"'