119 lines
3.0 KiB
PL/PgSQL
119 lines
3.0 KiB
PL/PgSQL
-- Taken from http://developer.postgresql.org/pgdocs/postgres/plpgsql-porting.html#PLPGSQL-PORTING-APPENDIX
|
|
|
|
--
|
|
-- instr functions that mimic Oracle's counterpart
|
|
-- Syntax: instr(string1, string2, [n], [m]) where [] denotes optional parameters.
|
|
--
|
|
-- Searches string1 beginning at the nth character for the mth occurrence
|
|
-- of string2. If n is negative, search backwards. If m is not passed,
|
|
-- assume 1 (search starts at first character).
|
|
--
|
|
|
|
CREATE FUNCTION instr(varchar, varchar) RETURNS integer AS $$
|
|
DECLARE
|
|
pos integer;
|
|
BEGIN
|
|
pos:= instr($1, $2, 1);
|
|
RETURN pos;
|
|
END;
|
|
$$ LANGUAGE plpgsql STRICT IMMUTABLE;
|
|
|
|
|
|
CREATE FUNCTION instr(string varchar, string_to_search varchar, beg_index integer)
|
|
RETURNS integer AS $$
|
|
DECLARE
|
|
pos integer NOT NULL DEFAULT 0;
|
|
temp_str varchar;
|
|
beg integer;
|
|
length integer;
|
|
ss_length integer;
|
|
BEGIN
|
|
IF beg_index > 0 THEN
|
|
temp_str := substring(string FROM beg_index);
|
|
pos := position(string_to_search IN temp_str);
|
|
|
|
IF pos = 0 THEN
|
|
RETURN 0;
|
|
ELSE
|
|
RETURN pos + beg_index - 1;
|
|
END IF;
|
|
ELSE
|
|
ss_length := char_length(string_to_search);
|
|
length := char_length(string);
|
|
beg := length + beg_index - ss_length + 2;
|
|
|
|
WHILE beg > 0 LOOP
|
|
temp_str := substring(string FROM beg FOR ss_length);
|
|
pos := position(string_to_search IN temp_str);
|
|
|
|
IF pos > 0 THEN
|
|
RETURN beg;
|
|
END IF;
|
|
|
|
beg := beg - 1;
|
|
END LOOP;
|
|
|
|
RETURN 0;
|
|
END IF;
|
|
END;
|
|
$$ LANGUAGE plpgsql STRICT IMMUTABLE;
|
|
|
|
|
|
CREATE FUNCTION instr(string varchar, string_to_search varchar,
|
|
beg_index integer, occur_index integer)
|
|
RETURNS integer AS $$
|
|
DECLARE
|
|
pos integer NOT NULL DEFAULT 0;
|
|
occur_number integer NOT NULL DEFAULT 0;
|
|
temp_str varchar;
|
|
beg integer;
|
|
i integer;
|
|
length integer;
|
|
ss_length integer;
|
|
BEGIN
|
|
IF beg_index > 0 THEN
|
|
beg := beg_index;
|
|
temp_str := substring(string FROM beg_index);
|
|
|
|
FOR i IN 1..occur_index LOOP
|
|
pos := position(string_to_search IN temp_str);
|
|
|
|
IF i = 1 THEN
|
|
beg := beg + pos - 1;
|
|
ELSE
|
|
beg := beg + pos;
|
|
END IF;
|
|
|
|
temp_str := substring(string FROM beg + 1);
|
|
END LOOP;
|
|
|
|
IF pos = 0 THEN
|
|
RETURN 0;
|
|
ELSE
|
|
RETURN beg;
|
|
END IF;
|
|
ELSE
|
|
ss_length := char_length(string_to_search);
|
|
length := char_length(string);
|
|
beg := length + beg_index - ss_length + 2;
|
|
|
|
WHILE beg > 0 LOOP
|
|
temp_str := substring(string FROM beg FOR ss_length);
|
|
pos := position(string_to_search IN temp_str);
|
|
|
|
IF pos > 0 THEN
|
|
occur_number := occur_number + 1;
|
|
|
|
IF occur_number = occur_index THEN
|
|
RETURN beg;
|
|
END IF;
|
|
END IF;
|
|
|
|
beg := beg - 1;
|
|
END LOOP;
|
|
|
|
RETURN 0;
|
|
END IF;
|
|
END;
|
|
$$ LANGUAGE plpgsql STRICT IMMUTABLE;
|