wild cards in MySQL using jdbc

[Aaron Jeffries]

Hello everyone.

The following statements works from a MySQL command line: SELECT * FROM drug WHERE otherBrands LIKE '%?%'

When I place it in the follow code there is a bad SQL message (below). If I remove the wildcards, the query runs fine. I've been playing around with variations of the MySQL statement with no luck.

I am breaking a syntax rule in jdbc somewhere?

Thanks so much.

  public Drug getDrugByGenericName(String name) {
		String sql = "SELECT * FROM drug WHERE otherBrands LIKE %?%";
		ParameterizedRowMapper<Drug> mapper = new ParameterizedRowMapper<Drug>() {
	        public Drug mapRow(ResultSet rs, int rowNum) throws SQLException {
	        	int id = rs.getInt("P_id");
	        	String drugName = rs.getString("name");
	        	String classOfDrug = rs.getString("classOfDrug");
	        	String whyIsThisMedicationPrescribed = rs.getString("whyIsThisMedicationPrescribed");
	        	String otherBrands = rs.getString("otherBrands");
	        	String sideEffects = rs.getString("sideEffects");
	        	String warnings = rs.getString("warnings");
	        	String treats = rs.getString("treats");
		
	        	Drug drug = new Drug (id, drugName, classOfDrug, whyIsThisMedicationPrescribed, otherBrands, sideEffects, warnings, treats);
	        	return drug;
	        }
		};

		try {return simpleJdbcTemplate.queryForObject(sql, mapper, name);
	     
	    } catch (TransientDataAccessResourceException e) {
	        return null;
	    }  

HTTP ERROR 500

Problem accessing /uRateDrugs-webapp/searchResultsByDrugName.html. Reason:

PreparedStatementCallback; bad SQL grammar [SELECT * FROM drug WHERE otherBrands LIKE %?%]; nested exception is 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 '%'hands'%' at line 1

Caused by:

org.springframework.jdbc.BadSqlGrammarException: PreparedStatementCallback; bad SQL grammar [SELECT * FROM drug WHERE otherBrands LIKE %?%]; nested exception is 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 '%'hands'%' at line 1
at org.springframework.jdbc.support.SQLErrorCodeSQLExceptionTranslator.doTranslate(SQLErrorCodeSQLExceptionTranslator.java:220)
at org.springframework.jdbc.support.AbstractFallbackSQLExceptionTranslator.translate(AbstractFallbackSQLExceptionTranslator.java:72)
at org.springframework.jdbc.core.JdbcTemplate.execute(JdbcTemplate.java:607)
at org.springframework.jdbc.core.JdbcTemplate.query(JdbcTemplate.java:641)
at org.springframework.jdbc.core.JdbcTemplate.query(JdbcTemplate.java:670)
at org.springframework.jdbc.core.JdbcTemplate.query(JdbcTemplate.java:678)
at org.springframework.jdbc.core.JdbcTemplate.queryForObject(JdbcTemplate.java:721)
at org.springframework.jdbc.core.simple.SimpleJdbcTemplate.queryForObject(SimpleJdbcTemplate.java:169)
at com.acwebsitedesign.uRateDrugs.domain.DrugRepositoryImpl.getDrugByGenericName(DrugRepositoryImpl.java:64)
at com.acwebsitedesign.uRateDrugs.domain.DrugServiceImpl.getDrugByGenericName(DrugServiceImpl.java:18)
at com.acwebsitedesign.uRateDrugs.web.SearchDrugsController.searchByResultsDrugName(SearchDrugsController.java:36)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.springframework.web.bind.annotation.support.HandlerMethodInvoker.doInvokeMethod(HandlerMethodInvoker.java:421)
at org.springframework.web.bind.annotation.support.HandlerMethodInvoker.invokeHandlerMethod(HandlerMethodInvoker.java:136)
at org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter.invokeHandlerMethod(AnnotationMethodHandlerAdapter.java:326)
at org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter.handle(AnnotationMethodHandlerAdapter.java:313)
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:875)
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:807)
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:571)
at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:511)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:727)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:820)
at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:502)
at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:390)
at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216)
at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:182)
at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:765)
at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:418)
at org.mortbay.jetty.handler.ContextHandlerCollection.handle(ContextHandlerCollection.java:230)
at org.mortbay.jetty.handler.HandlerCollection.handle(HandlerCollection.java:114)
at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
at org.mortbay.jetty.Server.handle(Server.java:326)
at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:536)
at org.mortbay.jetty.HttpConnection$RequestHandler.content(HttpConnection.java:928)
at org.mortbay.jetty.HttpParser.parseNext(HttpParser.java:747)
at org.mortbay.jetty.HttpParser.parseAvailable(HttpParser.java:218)
at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:405)
at org.mortbay.io.nio.SelectChannelEndPoint.run(SelectChannelEndPoint.java:409)
at org.mortbay.thread.QueuedThreadPool$PoolThread.run(QueuedThreadPool.java:582)
Caused by: 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 '%'hands'%' at line 1
at 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:406)
at com.mysql.jdbc.Util.getInstance(Util.java:381)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1030)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:956)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3491)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3423)
at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:1936)
at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2060)
at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2542)
at com.mysql.jdbc.PreparedStatement.executeInternal(PreparedStatement.java:1734)
at com.mysql.jdbc.PreparedStatement.executeQuery(PreparedStatement.java:1885)
at org.springframework.jdbc.core.JdbcTemplate$1.doInPreparedStatement(JdbcTemplate.java:648)
at org.springframework.jdbc.core.JdbcTemplate.execute(JdbcTemplate.java:591)
... 39 more

[Aaron Jeffries]

Hello everyone.

I was browsing other forums and found an answer to my question. One solution is to add wild cards to your prepared statement. In my case, it looked something like this:

return simpleJdbcTemplate.queryForObject(sql, mapper, "%" +name +"%");

Hope this helps someone else.

[Scott Selikoff]

You should put the wildcard % inside the prepared statement setString(). In your example, " LIKE %?%" will be often be replaced by the JDBC driver by" LIKE %'value'%" which is invalid SQL. In other words, put the % in the name string, not in the SQL string. Although, based on your error, I'm not sure you are using the queryForObject() properly.

[Aaron Jeffries]

Thanks Scott.

[Ben Morse]

Hey guys, I know this question is a bit different than OP, but how do I protect against this? If I'm using LIKE, and the method above, outside input will be interpreted as a %. How can I prevent this?

[Martin Vashko]

Welcome to the ranch, Ben!

A similar problem was recently discussed here: https://coderanch.com/t/598241/JDBC/databases/wrong-PreparedStatement#2729042

In short: the operand of the LIKE operator needs to be a varchar, so either a varchar literal (eg. LIKE "ABC%"), or a parameter (eg. LIKE ?), or a varchar expression (eg. LIKE "%" + ? + "%"). I'd go with the second option (LIKE ?) and use Java to wrap the actual value being searched for with percent signs (that is, ps.setString(index, "%" + textToSearchFor + "%")).

Also note that this kind of queries (LIKE with the leading wildcard character) tends to be very ineffective in most databases, because ordinary indexes cannot be used to answer these queries. Some databases support some kind of fulltext indexing, but this varies from DB to DB. I don't know any details about this, but I think it is in some form available in MySQL too.

[Ben Morse]

Martin,
Thanks for the welcome! Great information!