How to use a prepared statement correctly with Spring JDBCTemplate?

Question

I have to do a select query on a database which I will execute often. It works completely fine with a normal statement:

 List<Invoice> l = this.jdbcTemplate.query(
                     "SELECT id, name, stuff FROM example WHERE amount > ?",
                     new Object[] { "100" }, new RowMapper<Invoice>() {...} );

I execute the above statement very frequently, so for performance reason I want to use a prepared statement. However I'm now unsure how I correctly would use the spring API to achieve this.

I'm confused why spring would like me to give an instance of a PreparedStatementCreator as an argument for query? I thought that it's exactly the point that I do not create a new prepared statement every time I use the query method. So I think something along the line of the following snippet would be absolutely pointless as the prepared statement is created newly every time I call the query-method:

 List<Invoice> l = this.jdbcTemplate.query(
                     new PreparedStatementCreator() {
                         String query = "SELECT id, name, stuff FROM example WHERE amount > ?";
                         public PreparedStatement createPreparedStatement(Connection connection) throws SQLException {
                              return connection.prepareStatement(query);
                         }
                     },
                     new PreparedStatementSetter() {...}, 
                     new RowMapper<Invoice>() {...} );

Do I have to create my own ReusablePreparedStatementCreator? Which would only create a new method on the first call of createPreparedStatement.

Could the PreparedStatementCreatorFactory help me?

So to rephrase, how would I correctly create a select query that uses a prepared statement with Spring JDBCTemplate to really gain a performance advantage without losing the advantage of the RowMapper?

Answer 1

First of all, I'm not sure you would get a significant performance increase by not recreating the prepared statement every time, because the JDBC driver/database often caches prepared statements.

But if you want to execute multiple queries with a single prepared statement, simply use one of the execute() methods of JdbcTemplate, which creates a prepared statement from a SQL query (or lets you create it), and then executes a callback taking the prepared statement as argument. You can loop inside this callback, and execute the statement as many times you want.