Fix formatting issue in CAST MONEY to CHAR/VARCHAR (#3367) (#3393)

While CASTing money/smallmoney to (N)VARCHAR/(N)CHAR, the value get rounded
to 4 decimal places instead of 2. Fixed this by implementing CASTs from money to
CHAR/VARCHAR datatype which rounds off input money value to 2 decimal places and
converts it to string.

Additionally, while CASTing money values to (N)CHAR, the resultant string gets left padded
instead of usual right padding. This commit also fixes this issue.

Task: BABEL-5478
Signed-off-by: Rishabh Tanwar <[email protected]>

contrib/babelfishpg_common/sql/upgrades/babelfish_common_helper--3.7.0--3.8.0.sql

@@ -47,5 +47,32 @@ FOR TYPE sys.SMALLDATETIME USING btree FAMILY smalldatetime_ops AS
 END IF;
 END $$;
 
+CREATE OR REPLACE FUNCTION sys.fixeddecimal2varchar(sys.FIXEDDECIMAL, integer, BOOLEAN)
+RETURNS sys.VARCHAR
+AS 'babelfishpg_common', 'fixeddecimal2varchar'
+LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
+
+CREATE OR REPLACE FUNCTION sys.fixeddecimal2pgvarchar(sys.FIXEDDECIMAL, integer, BOOLEAN)
+RETURNS pg_catalog.VARCHAR
+AS 'babelfishpg_common', 'fixeddecimal2varchar'
+LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
+
+CREATE OR REPLACE FUNCTION sys.fixeddecimal2bpchar(sys.FIXEDDECIMAL, integer, BOOLEAN)
+RETURNS sys.BPCHAR
+AS 'babelfishpg_common', 'fixeddecimal2bpchar'
+LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
+
+CREATE CAST (sys.FIXEDDECIMAL AS sys.VARCHAR)
+WITH FUNCTION sys.fixeddecimal2varchar(sys.FIXEDDECIMAL, integer, BOOLEAN) AS IMPLICIT;
+
+CREATE CAST (sys.FIXEDDECIMAL AS pg_catalog.VARCHAR)
+WITH FUNCTION sys.fixeddecimal2pgvarchar(sys.FIXEDDECIMAL, integer, BOOLEAN) AS IMPLICIT;
+
+CREATE CAST (sys.FIXEDDECIMAL AS sys.BPCHAR)
+WITH FUNCTION sys.fixeddecimal2bpchar(sys.FIXEDDECIMAL, integer, BOOLEAN) AS IMPLICIT;
+
+CREATE CAST (sys.FIXEDDECIMAL AS pg_catalog.BPCHAR)
+WITH FUNCTION sys.fixeddecimal2bpchar(sys.FIXEDDECIMAL, integer, BOOLEAN) AS IMPLICIT;
+
 -- Reset search_path to not affect any subsequent scripts
 SELECT set_config('search_path', trim(leading 'sys, ' from current_setting('search_path')), false);

contrib/babelfishpg_common/sql/varchar.sql

@@ -302,6 +302,33 @@ LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
 CREATE CAST (sys.VARCHAR AS pg_catalog.NUMERIC)
 WITH FUNCTION sys.varchar2numeric(sys.VARCHAR) AS IMPLICIT;
 
+CREATE OR REPLACE FUNCTION sys.fixeddecimal2varchar(sys.FIXEDDECIMAL, integer, BOOLEAN)
+RETURNS sys.VARCHAR
+AS 'babelfishpg_common', 'fixeddecimal2varchar'
+LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
+
+CREATE OR REPLACE FUNCTION sys.fixeddecimal2pgvarchar(sys.FIXEDDECIMAL, integer, BOOLEAN)
+RETURNS pg_catalog.VARCHAR
+AS 'babelfishpg_common', 'fixeddecimal2varchar'
+LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
+
+CREATE OR REPLACE FUNCTION sys.fixeddecimal2bpchar(sys.FIXEDDECIMAL, integer, BOOLEAN)
+RETURNS sys.BPCHAR
+AS 'babelfishpg_common', 'fixeddecimal2bpchar'
+LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
+
+CREATE CAST (sys.FIXEDDECIMAL AS sys.VARCHAR)
+WITH FUNCTION sys.fixeddecimal2varchar(sys.FIXEDDECIMAL, integer, BOOLEAN) AS IMPLICIT;
+
+CREATE CAST (sys.FIXEDDECIMAL AS pg_catalog.VARCHAR)
+WITH FUNCTION sys.fixeddecimal2pgvarchar(sys.FIXEDDECIMAL, integer, BOOLEAN) AS IMPLICIT;
+
+CREATE CAST (sys.FIXEDDECIMAL AS sys.BPCHAR)
+WITH FUNCTION sys.fixeddecimal2bpchar(sys.FIXEDDECIMAL, integer, BOOLEAN) AS IMPLICIT;
+
+CREATE CAST (sys.FIXEDDECIMAL AS pg_catalog.BPCHAR)
+WITH FUNCTION sys.fixeddecimal2bpchar(sys.FIXEDDECIMAL, integer, BOOLEAN) AS IMPLICIT;
+
 CREATE OR REPLACE FUNCTION sys.nvarchar_larger(sys.NVARCHAR, sys.NVARCHAR)
 RETURNS sys.NVARCHAR
 AS 'text_larger'

contrib/babelfishpg_common/src/varchar.c

@@ -51,6 +51,12 @@ static inline int varcharTruelen(VarChar *arg);
 
 #define DEFAULT_LCID 1033
 
+/* Linkage to function in fixeddecimal module */
+typedef char *(*fixeddecimal2str_t) (int64 val, char *buffer,
+									 int64 fixeddecimal_multiplier,
+									 int64 fixeddecimal_scale);
+static fixeddecimal2str_t fixeddecimal2str_p = NULL;
+
 /*
  * is_basetype_nchar_nvarchar - given datatype is nvarchar or nchar
  *     or created over nvarchar or nchar.
@@ -382,6 +388,8 @@ PG_FUNCTION_INFO_V1(varchar2date);
 PG_FUNCTION_INFO_V1(varchar2time);
 PG_FUNCTION_INFO_V1(varchar2money);
 PG_FUNCTION_INFO_V1(varchar2numeric);
+PG_FUNCTION_INFO_V1(fixeddecimal2varchar);
+PG_FUNCTION_INFO_V1(fixeddecimal2bpchar);
 
 /*****************************************************************************
  *	 varchar - varchar(n)
@@ -930,6 +938,84 @@ varchar2numeric(PG_FUNCTION_ARGS)
 	PG_RETURN_NUMERIC(result);
 }
 
+#define FIXEDDECIMAL_2_VARCHAR_MULTIPLIER 100LL
+#define FIXEDDECIMAL_2_VARCHAR_SCALE 2
+Datum
+fixeddecimal2varchar(PG_FUNCTION_ARGS)
+{
+	int64		val = PG_GETARG_INT64(0);
+	int32		maxByteLen = PG_GETARG_INT32(1);
+	char		buf[MAXINT8LEN + 1];
+	char	   *end;
+	int32		len;
+	Datum		res;
+
+	/* fetch function pointer for cross-module calls. */
+	if (fixeddecimal2str_p == NULL)
+		fixeddecimal2str_p = (fixeddecimal2str_t)
+			load_external_function("$libdir/babelfishpg_money", "fixeddecimal2str", true, NULL);
+
+	end = fixeddecimal2str_p(val, buf, FIXEDDECIMAL_2_VARCHAR_MULTIPLIER, FIXEDDECIMAL_2_VARCHAR_SCALE);
+	len = (end - buf);
+
+	if (maxByteLen < 0)
+		maxByteLen = len + VARHDRSZ;
+	maxByteLen -= VARHDRSZ;
+	if (len > maxByteLen)
+		ereport(ERROR,
+				(errcode(ERRCODE_STRING_DATA_RIGHT_TRUNCATION),
+				 errmsg("There is insufficient result space to convert a money/smallmoney value to varchar/nvarchar.")));
+
+	res = DirectFunctionCall3(varcharin,
+							   CStringGetDatum(buf),
+							   ObjectIdGetDatum(0),
+							   Int32GetDatum(-1));
+
+	PG_RETURN_DATUM(res);
+}
+
+Datum
+fixeddecimal2bpchar(PG_FUNCTION_ARGS)
+{
+	int64		val = PG_GETARG_INT64(0);
+	int32		maxByteLen = PG_GETARG_INT32(1);
+	char		buf[MAXINT8LEN + 1];
+	char	   *buf_padded;
+	char	   *end;
+	int32		len;
+	Datum		res;
+
+	/* fetch function pointer for cross-module calls. */
+	if (fixeddecimal2str_p == NULL)
+		fixeddecimal2str_p = (fixeddecimal2str_t)
+			load_external_function("$libdir/babelfishpg_money", "fixeddecimal2str", true, NULL);
+
+	end = fixeddecimal2str_p(val, buf, FIXEDDECIMAL_2_VARCHAR_MULTIPLIER, FIXEDDECIMAL_2_VARCHAR_SCALE);
+	len = (end - buf);
+
+	if (maxByteLen < 0)
+		maxByteLen = len + VARHDRSZ;
+	maxByteLen -= VARHDRSZ;
+	if (len > maxByteLen)
+		ereport(ERROR,
+				(errcode(ERRCODE_STRING_DATA_RIGHT_TRUNCATION),
+				 errmsg("There is insufficient result space to convert a money/smallmoney value to varchar/nvarchar.")));
+
+	/* Left pad money value with the spaces */
+	buf_padded = (char *) palloc(maxByteLen + 1);
+	memset(buf_padded, ' ', maxByteLen - len);
+	memcpy(buf_padded + maxByteLen - len, buf, len);
+	buf_padded[maxByteLen] = '\0';
+	res = DirectFunctionCall3(bpcharin,
+							   CStringGetDatum(buf_padded),
+							   ObjectIdGetDatum(0),
+							   Int32GetDatum(-1));
+
+	PG_RETURN_DATUM(res);
+}
+#undef FIXEDDECIMAL_2_VARCHAR_MULTIPLIER
+#undef FIXEDDECIMAL_2_VARCHAR_SCALE
+
 /*****************************************************************************
  *	 bpchar - char()														 *
  *****************************************************************************/

contrib/babelfishpg_money/fixeddecimal.c

@@ -232,6 +232,9 @@ static int64 scanfixeddecimal(const char *str, int *precision, int *scale);
 static FixedDecimalAggState *makeFixedDecimalAggState(FunctionCallInfo fcinfo);
 static void fixeddecimal_accum(FixedDecimalAggState *state, int64 newval);
 static int64 int8fixeddecimal_internal(int64 arg, const char *typename);
+extern PGDLLEXPORT char *fixeddecimal2str(int64 val, char *buffer,
+										  int64 fixeddecimal_multiplier,
+										  int64 fixeddecimal_scale);
 
 /***********************************************************************
  **
@@ -392,12 +395,31 @@ pg_int64tostr_zeropad(char *str, int64 value, int64 padding)
  *		Prints the fixeddecimal 'val' to buffer as a string.
  *		Returns a pointer to the end of the written string.
  */
-static char *
-fixeddecimal2str(int64 val, char *buffer)
+char *
+fixeddecimal2str(int64 val, char *buffer,
+				int64 fixeddecimal_multiplier,
+				int64 fixeddecimal_scale)
 {
 	char	   *ptr = buffer;
-	int64		integralpart = val / FIXEDDECIMAL_MULTIPLIER;
-	int64		fractionalpart = val % FIXEDDECIMAL_MULTIPLIER;
+	int64		integralpart;
+	int64		fractionalpart;
+
+	/*
+	 * By default, fixeddecimal contains 4 digits after decimal but if we only need
+	 * 2 decimal points, remove last two decimal digits, round off remaining value.
+	 */
+	if (fixeddecimal_scale < 4)
+	{
+		int64		scale_factor = FIXEDDECIMAL_MULTIPLIER / (fixeddecimal_multiplier * 10);
+		int64		last_digit = abs(val / scale_factor) % 10;
+
+		val = val / fixeddecimal_multiplier;
+		if (last_digit >= 5)
+			val = val >= 0 ? val + 1LL : val - 1LL;
+	}
+
+	integralpart = val / fixeddecimal_multiplier;
+	fractionalpart = val % fixeddecimal_multiplier;
 
 	if (val < 0)
 	{
@@ -413,7 +435,7 @@ fixeddecimal2str(int64 val, char *buffer)
 	}
 	ptr = pg_int64tostr(ptr, integralpart);
 	*ptr++ = '.';
-	ptr = pg_int64tostr_zeropad(ptr, fractionalpart, FIXEDDECIMAL_SCALE);
+	ptr = pg_int64tostr_zeropad(ptr, fractionalpart, fixeddecimal_scale);
 	return ptr;
 }
 
@@ -810,7 +832,7 @@ fixeddecimalout(PG_FUNCTION_ARGS)
 {
 	int64		val = PG_GETARG_INT64(0);
 	char		buf[MAXINT8LEN + 1];
-	char	   *end = fixeddecimal2str(val, buf);
+	char	   *end = fixeddecimal2str(val, buf, FIXEDDECIMAL_MULTIPLIER, FIXEDDECIMAL_SCALE);
 
 	PG_RETURN_CSTRING(pnstrdup(buf, end - buf));
 }
@@ -2929,7 +2951,7 @@ fixeddecimalaggstateout(PG_FUNCTION_ARGS)
 	char		buf[MAXINT8LEN + 1 + MAXINT8LEN + 1];
 	char	   *p;
 
-	p = fixeddecimal2str(state->sumX, buf);
+	p = fixeddecimal2str(state->sumX, buf, FIXEDDECIMAL_MULTIPLIER, FIXEDDECIMAL_SCALE);
 	*p++ = ':';
 	p = pg_int64tostr(p, state->N);
 

contrib/babelfishpg_tsql/src/pltsql_coerce.c

@@ -232,6 +232,11 @@ tsql_cast_raw_info_t tsql_cast_raw_infos[] =
 	{TSQL_CAST_ENTRY, "sys", "bpchar", "pg_catalog", "name", "bpchar_to_name", 'i', 'f'},
 	{TSQL_CAST_ENTRY, "pg_catalog", "varchar", "pg_catalog", "name", "varchar_to_name", 'i', 'f'},
 	{TSQL_CAST_ENTRY, "sys", "varchar", "pg_catalog", "name", "varchar_to_name", 'i', 'f'},
+/*  fixeddecimal */
+	{PG_CAST_ENTRY, "sys", "fixeddecimal", "pg_catalog", "bpchar", NULL, 'i', 'f'},
+	{PG_CAST_ENTRY, "sys", "fixeddecimal", "sys", "bpchar", NULL, 'i', 'f'},
+	{PG_CAST_ENTRY, "sys", "fixeddecimal", "pg_catalog", "varchar", NULL, 'i', 'f'},
+	{PG_CAST_ENTRY, "sys", "fixeddecimal", "sys", "varchar", NULL, 'i', 'f'},
 /*  string -> float8 via I/O */
 	{TSQL_CAST_WITHOUT_FUNC_ENTRY, "pg_catalog", "text", "pg_catalog", "float8", NULL, 'i', 'i'},
 	{TSQL_CAST_WITHOUT_FUNC_ENTRY, "pg_catalog", "bpchar", "pg_catalog", "float8", NULL, 'i', 'i'},
@@ -302,11 +307,7 @@ tsql_cast_raw_info_t tsql_cast_raw_infos[] =
 	{TSQL_CAST_WITHOUT_FUNC_ENTRY, "pg_catalog", "numeric", "sys", "varchar", NULL, 'i', 'i'},
 /*  // fixeddecimal -> string via I/O */
 	{TSQL_CAST_WITHOUT_FUNC_ENTRY, "sys", "fixeddecimal", "pg_catalog", "text", NULL, 'i', 'i'},
-	{TSQL_CAST_WITHOUT_FUNC_ENTRY, "sys", "fixeddecimal", "pg_catalog", "bpchar", NULL, 'i', 'i'},
-	{TSQL_CAST_WITHOUT_FUNC_ENTRY, "sys", "fixeddecimal", "sys", "bpchar", NULL, 'i', 'i'},
-	{TSQL_CAST_WITHOUT_FUNC_ENTRY, "sys", "fixeddecimal", "pg_catalog", "varchar", NULL, 'i', 'i'},
-	{TSQL_CAST_WITHOUT_FUNC_ENTRY, "sys", "fixeddecimal", "sys", "varchar", NULL, 'i', 'i'},
-/*  fixeddecimal -> string via I/O */
+/*  uniqueidentifier -> string via I/O */
 	{TSQL_CAST_WITHOUT_FUNC_ENTRY, "sys", "uniqueidentifier", "pg_catalog", "text", NULL, 'i', 'i'},
 	{TSQL_CAST_WITHOUT_FUNC_ENTRY, "sys", "uniqueidentifier", "pg_catalog", "bpchar", NULL, 'i', 'i'},
 	{TSQL_CAST_WITHOUT_FUNC_ENTRY, "sys", "uniqueidentifier", "sys", "bpchar", NULL, 'i', 'i'},

test/JDBC/expected/BABEL-1193.out

@@ -221,9 +221,9 @@ SELECT * FROM t14;
 GO
 ~~START~~
 varchar#!#varchar#!#varchar#!#varchar#!#varchar#!#varchar#!#varchar#!#varchar
-12#!#4553#!#123456#!#12.345#!#2344.456#!#12.34#!#456.3334#!#1123.6777
--12#!#-1234#!#-123456#!#-12.345#!#-2344.456#!#12.34#!#-456.3334#!#-1123.6777
-0#!#0#!#0#!#0#!#0#!#0.00#!#0.0000#!#0.0000
+12#!#4553#!#123456#!#12.345#!#2344.456#!#12.34#!#456.33#!#1123.68
+-12#!#-1234#!#-123456#!#-12.345#!#-2344.456#!#12.34#!#-456.33#!#-1123.68
+0#!#0#!#0#!#0#!#0#!#0.00#!#0.00#!#0.00
 ~~END~~
 
 -- numeric types -> char(10)
@@ -237,9 +237,9 @@ SELECT * FROM t15;
 GO
 ~~START~~
 char#!#char#!#char#!#char#!#char#!#char#!#char#!#char
-12                  #!#4553                #!#123456              #!#12.345              #!#2344.456            #!#12.34               #!#456.3334            #!#1123.6777           
--12                 #!#-1234               #!#-123456             #!#-12.345             #!#-2344.456           #!#12.34               #!#-456.3334           #!#-1123.6777          
-0                   #!#0                   #!#0                   #!#0                   #!#0                   #!#0.00                #!#0.0000              #!#0.0000              
+12                  #!#4553                #!#123456              #!#12.345              #!#2344.456            #!#12.34               #!#              456.33#!#             1123.68
+-12                 #!#-1234               #!#-123456             #!#-12.345             #!#-2344.456           #!#12.34               #!#             -456.33#!#            -1123.68
+0                   #!#0                   #!#0                   #!#0                   #!#0                   #!#0.00                #!#                0.00#!#                0.00
 ~~END~~
 
 
@@ -248,7 +248,7 @@ select upper(cast (1 as smallint)), upper(cast (1 as int)), upper(cast (1 as big
 GO
 ~~START~~
 varchar#!#varchar#!#varchar#!#varchar#!#varchar#!#varchar#!#varchar#!#varchar
-1#!#1#!#1#!#1#!#1#!#2.1#!#1.0000#!#1.0000
+1#!#1#!#1#!#1#!#1#!#2.1#!#1.00#!#1.00
 ~~END~~
 
 select round(cast ('123' as text), 1), round(cast ('123' as char(3)), 1), round(cast ('123' as varchar(3)), 1);

test/JDBC/expected/BABEL-3486-vu-verify.out

@@ -1586,7 +1586,7 @@ SELECT * FROM BABEL_3486_vu_prepare_v63
 GO
 ~~START~~
 varchar
-1.0000
+1.00
 ~~END~~
 
 DROP VIEW BABEL_3486_vu_prepare_v63
@@ -1596,7 +1596,7 @@ EXEC BABEL_3486_vu_prepare_p63
 GO
 ~~START~~
 varchar
-1.0000
+1.00
 ~~END~~
 
 DROP PROCEDURE BABEL_3486_vu_prepare_p63

test/JDBC/expected/BABEL-889-vu-verify.out

@@ -131,7 +131,7 @@ select cast(cast(cast('$123.123' as money) as sql_variant) as varchar);
 go
 ~~START~~
 varchar
-123.1230
+123.12
 ~~END~~
 
 -- smallmoney
@@ -146,7 +146,7 @@ select cast(cast(cast('$123.123' as smallmoney) as sql_variant) as varchar);
 go
 ~~START~~
 varchar
-123.1230
+123.12
 ~~END~~
 
 -- bigint

test/JDBC/expected/BABEL-889.out

@@ -131,7 +131,7 @@ select cast(cast(cast('$123.123' as money) as sql_variant) as varchar);
 go
 ~~START~~
 varchar
-123.1230
+123.12
 ~~END~~
 
 -- smallmoney
@@ -146,7 +146,7 @@ select cast(cast(cast('$123.123' as smallmoney) as sql_variant) as varchar);
 go
 ~~START~~
 varchar
-123.1230
+123.12
 ~~END~~
 
 -- bigint

test/JDBC/expected/babel_functions_cast.out

@@ -127,14 +127,14 @@ select CAST(CAST(4936.56 AS MONEY) AS varchar(10));
 GO
 ~~START~~
 varchar
-4936.5600
+4936.56
 ~~END~~
 
 select CAST(CAST(-4936.56 AS MONEY) AS varchar(10));
 GO
 ~~START~~
 varchar
--4936.5600
+-4936.56
 ~~END~~
 
 select CAST(4936.56 AS smallmoney);
@@ -955,14 +955,14 @@ select TRY_CAST(TRY_CAST(4936.56 AS MONEY) AS varchar(10));
 GO
 ~~START~~
 varchar
-4936.5600
+4936.56
 ~~END~~
 
 select TRY_CAST(TRY_CAST(-4936.56 AS MONEY) AS varchar(10));
 GO
 ~~START~~
 varchar
--4936.5600
+-4936.56
 ~~END~~
 
 select TRY_CAST(4936.56 AS smallmoney);