Adding fix for edge cases in Space function (#2807)

* Adding fix for edge cases in Space function (#2742)

Currently for string function SPACE() we only handle positive integers and throws error for input 0 or negative number.

This commit will handle those edge cases and when a negative number is passed we will return NULL and when 0 is passed we will return an empty string. Additionally, this commit adds handling when input integer is greater than 8000.

Task: BABEL-4811
Signed-off-by: Tanya Gupta <[email protected]>

contrib/babelfishpg_tsql/sql/sys_functions.sql

@@ -1510,10 +1510,13 @@ STRICT
 LANGUAGE SQL IMMUTABLE;
 
 CREATE OR REPLACE FUNCTION sys.space(IN number INTEGER, OUT result SYS.VARCHAR) AS $$
--- sys.varchar has default length of 1, so we have to pass in 'number' to be the
--- type modifier.
 BEGIN
-	EXECUTE pg_catalog.format(E'SELECT repeat(\' \', %s)::SYS.VARCHAR(%s)', number, number) INTO result;
+    IF number < 0 THEN
+        result := NULL;
+    ELSE
+        -- TSQL has a limitation of 8000 character spaces for space function.
+        result := PG_CATALOG.repeat(' ',least(number, 8000));
+    END IF;
 END;
 $$
 STRICT

contrib/babelfishpg_tsql/sql/upgrades/babelfishpg_tsql--3.6.0--3.7.0.sql

@@ -10010,6 +10010,19 @@ BEGIN
 END;
 $$ LANGUAGE plpgsql IMMUTABLE STRICT PARALLEL SAFE;
 
+CREATE OR REPLACE FUNCTION sys.space(IN number INTEGER, OUT result SYS.VARCHAR) AS $$
+BEGIN
+    IF number < 0 THEN
+        result := NULL;
+    ELSE
+        -- TSQL has a limitation of 8000 character spaces for space function.
+        result := PG_CATALOG.repeat(' ',least(number, 8000));
+    END IF;
+END;
+$$
+STRICT
+LANGUAGE plpgsql;
+
 -- Drops the temporary procedure used by the upgrade script.
 -- Please have this be one of the last statements executed in this upgrade script.
 DROP PROCEDURE sys.babelfish_drop_deprecated_object(varchar, varchar, varchar);

test/JDBC/expected/space-vu-cleanup.out

@@ -0,0 +1,50 @@
+DROP FUNCTION babel_4811_vu_prepare_f1
+GO
+
+DROP FUNCTION babel_4811_vu_prepare_f2
+GO
+
+DROP FUNCTION babel_4811_vu_prepare_f3
+GO
+
+DROP PROCEDURE babel_4811_vu_prepare_p1
+GO
+
+DROP PROCEDURE babel_4811_vu_prepare_p2
+GO
+
+DROP VIEW babel_4811_vu_prepare_v1
+GO
+
+DROP VIEW babel_4811_vu_prepare_v2
+GO
+
+DROP VIEW  babel_4811_vu_prepare_v3
+GO
+
+DROP VIEW babel_4811_vu_prepare_v4
+GO
+
+DROP VIEW babel_4811_vu_prepare_v5
+GO
+
+DROP VIEW babel_4811_vu_prepare_v6
+GO
+
+DROP VIEW babel_4811_vu_prepare_v7
+GO
+
+DROP VIEW babel_4811_vu_prepare_v8
+GO
+
+DROP VIEW babel_4811_vu_prepare_v9
+GO
+
+DROP TABLE babel_4811_vu_prepare_t1
+GO
+
+DROP TABLE babel_4811_vu_prepare_t2
+GO
+
+DROP TABLE babel_4811_vu_prepare_t3
+GO

test/JDBC/expected/space-vu-prepare.out

@@ -0,0 +1,91 @@
+CREATE TABLE babel_4811_vu_prepare_t1(number int)
+GO
+INSERT INTO babel_4811_vu_prepare_t1 VALUES(5)
+GO
+~~ROW COUNT: 1~~
+
+
+CREATE TABLE babel_4811_vu_prepare_t2(number int)
+GO
+INSERT INTO babel_4811_vu_prepare_t2 VALUES(-10)
+GO
+~~ROW COUNT: 1~~
+
+
+CREATE TABLE babel_4811_vu_prepare_t3(number int)
+GO
+INSERT INTO babel_4811_vu_prepare_t3 VALUES(0)
+GO
+~~ROW COUNT: 1~~
+
+
+CREATE FUNCTION babel_4811_vu_prepare_f1(@number int)
+returns int
+BEGIN
+    RETURN DATALENGTH(SPACE(@number))
+END
+GO
+
+CREATE FUNCTION babel_4811_vu_prepare_f2(@number int)
+returns varchar(20)
+BEGIN
+    RETURN '|' + SPACE(@number) + '|'
+END
+GO
+
+CREATE FUNCTION babel_4811_vu_prepare_f3()
+returns table
+AS
+    RETURN (select '|' + SPACE(number) + '|' as result from babel_4811_vu_prepare_t1)
+GO
+
+CREATE PROCEDURE babel_4811_vu_prepare_p1 (@number AS INT)
+AS
+BEGIN
+SELECT DATALENGTH(SPACE(@number))
+END;
+GO
+
+CREATE PROCEDURE babel_4811_vu_prepare_p2 (@number AS INT)
+AS
+BEGIN
+SELECT '|' + SPACE(@number) + '|' AS result
+END;
+GO
+
+CREATE VIEW babel_4811_vu_prepare_v1 AS
+SELECT DATALENGTH(SPACE(10)) as result
+GO
+
+
+CREATE VIEW babel_4811_vu_prepare_v2 AS
+SELECT DATALENGTH(SPACE(0)) as result
+GO
+
+CREATE VIEW babel_4811_vu_prepare_v3 AS
+SELECT DATALENGTH(SPACE(-10)) as result
+GO
+
+CREATE VIEW babel_4811_vu_prepare_v4 AS
+    SELECT DATALENGTH(SPACE(number)) as result FROM babel_4811_vu_prepare_t1
+GO
+
+CREATE VIEW babel_4811_vu_prepare_v5 AS
+    SELECT DATALENGTH(SPACE(number)) as result FROM babel_4811_vu_prepare_t2
+GO
+
+CREATE VIEW babel_4811_vu_prepare_v6 AS
+    SELECT DATALENGTH(SPACE(number)) as result FROM babel_4811_vu_prepare_t3
+GO
+
+CREATE VIEW babel_4811_vu_prepare_v7 AS
+SELECT '|' + SPACE(10) + '|' AS result
+GO
+
+CREATE VIEW babel_4811_vu_prepare_v8 AS
+SELECT '|' + SPACE(0) + '|' AS result
+GO
+
+CREATE VIEW babel_4811_vu_prepare_v9 AS
+SELECT '|' + SPACE(-10) + '|' AS result
+GO