How to use a list of string in NamedParameterJDBCT

问题:

Experimenting with Spring-JDBC. I am using this as reference. I am trying to get a list of actors who have the same last name. Running this code gave me the desired results:

public List<String> getActorsWithSameLastName(String lastName,
            NamedParameterJdbcTemplate template) {
        String query = "SELECT FIRSTNAME FROM ACTORS WHERE LASTNAME=:LASTNAME";
        Map<String, String> paramMap = new HashMap<String, String>();
        paramMap.put("LASTNAME", lastName);
        return template.queryForList(query, paramMap, String.class);
    }

I have a List<String> of last names. How can I get a List of actors with the list that I have? Do I iterate over the list of last names and call the getActorsWithSameLastName() everytime or does spring provide a way where it does the iteration and fetches the result for me? Please advice.

回答1:

Use IN Clause..

How to use SELECT IN clause in JDBCTemplates?

List<String> lastnames= new ArrayList<>();

Map namedParameters = Collections.singletonMap("lastnamevalues", lastnames);

StringBuffer recordQueryString = new StringBuffer();

recordQueryString.append("select FIRSTNAME, LASTNAME from ACTORS where lastname in (:lastnamevalues)");

List nameInvolvements = this.namedparameterJdbcTemplate.query(recordQueryString.toString(), namedParameters, new MyMapper());

回答2:

You can also use MapSqlParameterSource

String query = "SELECT FIRSTNAME FROM ACTORS WHERE LASTNAME in (:LASTNAME)";
Set<String> ids = ....;

MapSqlParameterSource parameters = new MapSqlParameterSource();
parameters.addValue("LASTNAME", ids);

this.namedparameterJdbcTemplate.query(query, parameters);