Error executing MySQL query via ebean using RawSql

问题

In a Play! 2.x application, I'm trying to send a simple query to a MySQL server using ebean.

My complete class looks as follows:

public static List<Venue> search(String query) {
    List<Venue> matches = new ArrayList<Venue>();
    try {
        String q = query.replace(" ", "");

        String sql =    "SELECT  v.id, c.company, c.postcode \n" +
                        "FROM    venue v \n" +
                        "JOIN    contact c ON (c.id = v.id) \n" +
                        "WHERE   REPLACE(c.postcode, ' ', '') LIKE '%" + q + "%' \n" +
                        "    OR  c.company LIKE '%" + q + "%'";

        RawSql rawSql = RawSqlBuilder.unparsed(sql)
            .columnMapping("v.id", "id")
            .columnMapping("c.company", "contact.company")
            .columnMapping("c.postcode", "contact.postcode")
            .create();

        Query<Venue> eQ = Ebean.find(Venue.class);

        eQ.setRawSql(rawSql);

        matches = eQ.findList();
    }
    catch (Exception e) {
        Utils.eHandler("Venue.search(" + query + ")", e);
    }
    finally {
        return matches;
    }
}

However, executing the line...

matches = eQ.findList();

..results in the following error, which appears to be a MySQL error(?):

Query threw SQLException:Column Index out of range, 0 < 1.
Bind values:[]
Query was:
SELECT  v.id, c.company, c.postcode
FROM    venue v
JOIN    contact c ON (c.id = v.id)
WHERE   REPLACE(c.postcode, ' ', '') LIKE '%sw3%'
        OR  c.company LIKE '%sw3%'

The query itself is fine, for example I can copy the version from the error message, paste it into MySQL Workbench, and it executes no problem.

Note that I'm using RawSql because I'll need to have more than 2 "OR" clauses, and as far as I know this is the only way to do it.

Can anyone help?

Thanks!

回答1:

Found the problem (or a solution, at least). As "Contact" is a child object of "Venue", you can't map to Contact fields (e.g. "contact.company") without specifying the Contact identifier. So, the following code, with appropriate elements added for contact.id, works:

String sql =    "SELECT  v.id, c.id, c.company, c.postcode " +
                "FROM    venue v " +
                "JOIN    contact c ON (c.id = v.id) " +
                "WHERE   REPLACE(c.postcode, ' ', '') LIKE '%" + q + "%' " +
                "    OR  c.company LIKE '%" + q + "%'";

RawSql rawSql = RawSqlBuilder.unparsed(sql)
    .columnMapping("v.id", "id")
    .columnMapping("c.id", "contact.id")
    .columnMapping("c.company", "contact.company")
    .columnMapping("c.postcode", "contact.postcode")
    .create();

Even better than that, since the routine is just returning a list of "Venue" objects that are matched in the query, it's not even necessary to include the additional fields, so all I really needed was the following (which also works):

String sql =    "SELECT  v.id " +
                "FROM    venue v " +
                "JOIN    contact c ON (c.id = v.id) " +
                "WHERE   REPLACE(c.postcode, ' ', '') LIKE '%" + q + "%' " +
                "    OR  c.company LIKE '%" + q + "%'";

RawSql rawSql = RawSqlBuilder.unparsed(sql)
    .columnMapping("v.id", "id")
    .create();

来源：https://stackoverflow.com/questions/13977693/error-executing-mysql-query-via-ebean-using-rawsql