How to get the data type of a column?

Question

I plan to construct a dynamic insert statement, so the column's type is needed, any possible to get what type of a column within mysql's table?
Message was edited by:
ioiioi

Answer 1

Think about it this way
You can find out the type of the columns but can you convert the data items that you have to insert in to the table in to the proper column type. And you will also have to write a long if-else-if if you try to do this.
Just make the JDBC driver worry about this.
Try something like this.
public void insert(String table, Object data[]){
   //You should write the getNumCollumns method
   //to return the number of columns in the table
   // Using Matadata Objects
   int noOfColumns = getNumCollumns(table);
   if (noOfColumns  != data.length)
      throw new IncorrectNumberOfValuesException();
   //You should write this exception probably to be a subclass of SQLException
   //Now construct the insert statement
   StringBuffer sb = new StringBuffer("INSERT INTO ");
   sb.append(table);
   sb.append(" VALUES (");
   for (int i=0; i<noOfColumns ; i++){
      sb.append("?");
      if (i< (noOfColumns-1))
         sb.append(",");
   sb.append(")");
  //If you want you can cache the statement againt the table name
  //Now create your prepared statement
  PreparedStatement ps = connection.prepareStatement(sb.toString());
  //Set the data
  for (int i=0; i<data.length; i++){
      ps.setObject(i+1, data);
//Execute
ps.executeUpdate();
ps.close();
In the above code the caller is responsible for sending the data with proper java type to be inserted and the driver will do the conversion. I have used this approach in a project few years ago and I havent got any complains.
WARNING: I havent compiled above code. It may have typos