java Spring JDBCTemplate - where clause - spring

Question

In my JDBC training, I have a question on the use of the where clause.
Suppose that i have a table in my db that i want manage with a spring application using a jdbc template, let's assume "Logbase", with this column: host, user, clientip. Suppose now that i want allow query db based on a single column for all column, that is:
Select * from Logbase where host = x
and
Select * from Logbase where user = y
and
Select * from Logbase where clientip = z
I suppose I must write a separated java method for every of this query, something like this:
public Logbase getLogbaseFromHost(String id)
{
String SQL = "select * from Logbase where host = ?";
Logbase logbase = (Logbase) jdbcTemplate.queryForObject(SQL, new Object[]{id},
(rs, rowNum) -> new Logbase(rs.getString("host"), rs.getString("user"),
rs.getInt("clientip")));
return logbase;
}
public Logbase getLogbaseFromUser(String id)
{
String SQL = "select * from Logbase where user = ?";
Logbase logbase = (Logbase) jdbcTemplate.queryForObject(SQL, new Object[]{id},
(rs, rowNum) -> new Logbase(rs.getString("host"), rs.getString("user"),
rs.getInt("clientip")));
return logbase;
}
public Logbase getLogbaseFromClientIP(String id)
{
String SQL = "select * from Logbase where clientip = ?";
Logbase logbase = (Logbase) jdbcTemplate.queryForObject(SQL, new Object[]{id},
(rs, rowNum) -> new Logbase(rs.getString("host"), rs.getString("user"),
rs.getInt("clientip")));
return logbase;
}
Now, if i want allow query db based on 2 parameters, i suppose i must write a method for the 3 possible pair of parameters (one for clientip-user, another for clientip-host and the last for user-host).
Finally, if i want allow query db selecting all the parameters, i must write another method with the where clause in the query that ask for all variables.
If I did not say heresies and everything is correct, i have 7 method. But, i the number of parameters and combinations grow, this may be a problem. There is a way to get around it?
Note: for work reasons, i cant use Hibernate or other ORM framework. I MUST use jdbc.
Tnx to all for patience and response.

Answer 1

The solution could be based on SQL
Select *
from Logbase
where
(? is null or host = ?)
AND (? is null or user = ?)
AND (? is null or clientip = ?)
jdbcTemplate.queryForObject(SQL, new Object[]{host, host, user, user, clienttip, clienttip}
So e.g. if user is not specified (user is null - true) all the records are included

Answer 2

So, you also can use org.springframework.jdbc.core.namedparam.NamedParameterJdbcTemplate
** Select *
from Logbase where
(:host is null or host = :host)
AND (:user is null or user = :user)
AND (:clientip is null or clientip = :clientip)**
And java code:
MapSqlParameterSource params = new MapSqlParameterSource();
params.addValue("host", host);
params.addValue("user", user);
params.addValue("clientip", clientip);
namedParameterJdbcTemplate.queryForObject(sqlQuer, params);