連線資料庫報“You have an error in your SQL syntax”異常的解決
問題描述：
在做一個部落格系統的過程中，使用連線池連線資料庫時出現問題。使用的是Mysql資料庫，向資料庫中插入資料時出錯，錯誤提示如下：
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 '?,?,?,now())' at line 1at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)at java.lang.reflect.Constructor.newInstance(Constructor.java:513)at com.mysql.jdbc.Util.handleNewInstance(Util.java:409)at com.mysql.jdbc.Util.getInstance(Util.java:384)at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1054)at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3566)at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3498)at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:1959)at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2113)at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2562)at com.mysql.jdbc.StatementImpl.executeUpdate(StatementImpl.java:1664)at com.mysql.jdbc.StatementImpl.executeUpdate(StatementImpl.java:1583)at org.apache.tomcat.dbcp.dbcp.DelegatingStatement.executeUpdate(DelegatingStatement.java:228)at org.apache.tomcat.dbcp.dbcp.DelegatingStatement.executeUpdate(DelegatingStatement.java:228)at com.chenzheng.blog.BlogServlet.doPost(BlogServlet.java:52)at javax.servlet.http.HttpServlet.service(HttpServlet.java:637)at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:298)at org.apache.coyote.http11.Http11AprProcessor.process(Http11AprProcessor.java:861)at org.apache.coyote.http11.Http11AprProtocol$Http11ConnectionHandler.process(Http11AprProtocol.java:579)at org.apache.tomcat.util.net.AprEndpoint$Worker.run(AprEndpoint.java:1584)at java.lang.Thread.run(Thread.java:619)
涉及的程式程式碼如下：
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 | DataSource ds =null; try { Context context =new InitialContext(); ds = (DataSource) context.lookup("java:/comp/env/jdbc/mysqlds"); }catch (NamingException e) { System.out.println("獲取資料來源時出錯！"); } try { Connection conn = ds.getConnection(); String insertBlog ="insert into blog(title,content,category_id,createdtime) values(?,?,?,now())"; PreparedStatement pstmt = conn.prepareStatement(insertBlog); pstmt.setString(1, title); pstmt.setString(2, content); pstmt.setInt(3, Integer.parseInt(categoryId)); pstmt.executeUpdate(insertBlog); }catch (SQLException e) { e.printStackTrace(); } |
解決方法：