Using Integer Array in postgres with Spring-boot - postgresql

Question

I am attempting to accept from the browser a List and use this within a SQL query to a postgres database. I have the following code snippet that tries to show the function that I have made todo this. Some of the variables have been changed in case there appears to be discrepancies.
static public List<Map<String,Object>> fetch(NamedParameterJdbcTemplate jdbcTemplate, List<Integer> id){
List<Map<String,Object>> result= new ArrayList<>();
String sql = "select * from lookup where id && ARRAY[ :ids ]";
MapSqlParameterSource parameters = new MapSqlParameterSource();
parameters.addValue("ids",id, Types.INTEGER);
result= jdbcTemplate.query(sql,
parameters,
new RowMapper<Map<String,Object>>() { ...
}
)
}
The lookup tables id field is a postgress array hence me needing to use && and the array function
This function is called by many different endpoints and passes the NamedParameterJdbcTemplate as well as a list of Integers. The problem I am having is that if any integer in the list is < 100 I get the following message
Bad value for type int : {20}
Is there another way of doing this or a way around this error ?
EDIT:
It appears it was part of the problem mentioned as the answer but also using
rs.getInt(col)
instead of
rs.getArray(col)

Answer 1

There's an error I can see in the SQL, and probably the wrong choice of API after that. First in the query:
select * from lookup where id && ARRAY[ :ids ]
To bind an array parameter, it must not be placed in the ARRAY constructor, but rather you need to use JDBC binding like this:
select * from lookup where id && ?
As you've noticed I'm not using a named parameter in these examples, because NamedParameterJdbcTemplate does not provide a route to obtaining the java.sql.Connection object or a proxy to it. You can access it through the PreparedStatementSetter if you use the JdbcOperations interface instead.
public static List<Map<String,Object>> fetch(NamedParameterJdbcTemplate jdbcTemplate, List<Integer> idlist){
List<Map<String,Object>> result= new ArrayList<>();
String sql = "select * from lookup where id && ?";
final Integer[] ids = idlist.toArray(new Integer[0]);
PreparedStatementSetter parameters = new PreparedStatementSetter() {
#Override
void setValues(PreparedStatement stmt) {
Connection conn = stmt.getConnection();
// this can only be done through the Connection
java.sql.Array arr = conn.createArrayOf("integer", ids);
// you can use setObject(1, ids, java.sql.Types.ARRAY) instead of setArray
// in case the connection wrapper doesn't pass it on to the JDBC driver
stmt.setArray(1, ids);
}
};
JdbcOperations jdo = jdbcTemplate.getJdbcOperations();
result= jdo.query(sql,
parameters,
new RowMapper<Map<String,Object>>() { ...
}
)
}
There might be errors in the code, since I normally use a different set of APIs, and you need a try-catch block for java.sql.SQLException in that setValues function, but you should be able to handle it from here on.