passing java string variable in mysql query

Question

How to pass java string variable in sql query .I have done all the JDBC connection .

My sql database query is

sql = \"Select * 
       from productio         


        

Answer 1

Whenever I have to make sql queries I use a library like jdbi to do it. This will allow you to create an interface with different queries. All you have to do is define the interface, create a POJO, and create a mapper between a SQL table and a Java POJO.

The interface would look something like this.

@RegisterMapper(ProductionMapper.class)
public interface ProductionDAO {
     @SqlQuery("Select * from production AS cust INNER JOIN location AS comp ON cust.location_id = comp.location_id where comp.name = :name AND crop_id =1")
     Production findRow(@Bind("name") String name);
    } 

The POJO would look something like this.

public class Production {
   private VariableTypeA variableA;
   // other variables
   public Production(VariableTypeA variableA ....) {
      this.variableA = variableA;
      // set everything else
   }
   // getters and setters
}

The mapper would look something like this.

public class ProductionMapper implements ResultSetMapper {
  public Production map(int index, ResultSet r, StatementContext ctx) throws SQLException {
    return new Production(r.getSomeType("columnName"), ...);
  }
}

This design makes it really simple to interact with your database and pass variables as well as making it so that your classes dont violate the SRP

http://jdbi.org/sql_object_overview/