我有以下 postgresql 函数:
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'; …Run Code Online (Sandbox Code Playgroud)