Are there named parameters in JDBC instead of positional ones, like the @name, @city in the ADO.NET query below?
select * from customers where name=@name and city = @city
Are there named parameters in JDBC instead of positional ones, like the @name, @city in the ADO.NET query below?
select * from customers where name=@name and city = @city
JDBC does not support named parameters. Unless you are bound to using plain JDBC (which causes pain, let me tell you that) I would suggest to use Springs Excellent JDBCTemplate which can be used without the whole IoC Container.
NamedParameterJDBCTemplate supports named parameters, you can use them like that:
NamedParameterJdbcTemplate jdbcTemplate = new NamedParameterJdbcTemplate(dataSource);
MapSqlParameterSource paramSource = new MapSqlParameterSource();
paramSource.addValue("name", name);
paramSource.addValue("city", city);
jdbcTemplate.queryForRowSet("SELECT * FROM customers WHERE name = :name AND city = :city", paramSource);
Vanilla JDBC only supports named parameters in a CallableStatement (e.g. setString("name", name)), and even then, I suspect the underlying stored procedure implementation has to support it.
An example of how to use named parameters:
//uss Sybase ASE sysobjects table...adjust for your RDBMS
stmt = conn.prepareCall("create procedure p1 (@id int = null, @name varchar(255) = null) as begin "
+ "if @id is not null "
+ "select * from sysobjects where id = @id "
+ "else if @name is not null "
+ "select * from sysobjects where name = @name "
+ " end");
stmt.execute();
//call the proc using one of the 2 optional params
stmt = conn.prepareCall("{call p1 ?}");
stmt.setInt("@id", 10);
ResultSet rs = stmt.executeQuery();
while (rs.next())
{
System.out.println(rs.getString(1));
}
//use the other optional param
stmt = conn.prepareCall("{call p1 ?}");
stmt.setString("@name", "sysprocedures");
rs = stmt.executeQuery();
while (rs.next())
{
System.out.println(rs.getString(1));
}
You can't use named parameters in JDBC itself. You could try using Spring framework, as it has some extensions that allow the use of named parameters in queries.