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我有以下PostgreSQL函数:返回结果集与PostgreSQL的存储过程的列名
CREATE OR REPLACE FUNCTION readMessage(messageFor INT, qid INT = NULL, ctxt INT = NULL, messageFrom INT = NULL, byTimeStamp BOOLEAN = FALSE)
RETURNS SETOF message
AS $$
DECLARE
sql varchar;
BEGIN
sql := 'SELECT * FROM message WHERE (receiver_id IS NULL OR receiver_id = $1)';
IF qid IS NOT NULL THEN
sql := sql || ' AND queue_id = $2';
END IF;
IF ctxt IS NOT NULL THEN
sql := sql || ' AND context = $3';
ELSE
sql := sql || ' AND context IS NULL';
END IF;
IF $4 IS NOT NULL THEN
sql := sql || ' AND sender_id = $4';
END IF;
sql := sql || ' ORDER BY';
IF byTimeStamp THEN
sql := sql || ' arrive_time ASC';
ELSE
sql := sql || ' priority DESC';
END IF;
sql := sql || ' LIMIT 1';
RETURN QUERY EXECUTE sql
USING messageFor, qid, ctxt, messageFrom;
END;
$$
LANGUAGE plpgsql;
现在,上面的功能工作正常,但结果集不包含列名(例如:一个简单的SELECT语句返回结果与列名称)。我需要能够访问 在Java代码中为上述函数的结果:
Connection con;
PreparedStatement ps = con.prepareStatement("select readMessage(1, 1, 1, 1, true))";
ResultSet rs = ps.executeQuery();
rs.getInt(<column-name>) // for example: 'queue_id', 'context' etc.
,而不是
rs.getInt(<column-index>)
更多可读的代码。我如何修改我的postgresql功能来实现这一目标?