fix for char and nchar function correct handling

contrib/babelfishpg_common/sql/string_operators.sql

@@ -97,28 +97,34 @@ CREATE OPERATOR sys.+ (
     FUNCTION = sys.babelfish_concat_wrapper
 );
 
-create or replace function sys.CHAR(x in int)returns char
+create or replace function sys.cht_(x in int) returns sys.varchar
 AS
 $body$
 BEGIN
 /***************************************************************
 EXTENSION PACK function CHAR(x)
 ***************************************************************/
+    if x = 0 then 
+        return ('\x00'::bytea)::sys.varbinary;
+    end if;
     if x between 1 and 255 then
         return chr(x);
     else
         return null;
     end if;
 END;
 $body$
-language plpgsql STABLE;
+LANGUAGE plpgsql IMMUTABLE STRICT PARALLEL SAFE;
 
-CREATE OR REPLACE FUNCTION sys.nchar(IN x INTEGER) RETURNS sys.nvarchar
+CREATE OR REPLACE FUNCTION sys.ncht_(x in int) RETURNS sys.nvarchar
 AS
 $body$
 BEGIN
-    --- 1114111 is 0x10FFFF - max value permitted as specified by documentation
-    if x between 1 and 1114111 then
+    if x = 0 then 
+        return ('\x00'::bytea)::sys.varbinary;
+    end if;
+    --- 65535 is 0x0000FFFF - max value permitted as specified by documentation without SC collation
+    if x between 1 and 65535 then
         return(select chr(x))::sys.nvarchar;
     else
         return null;
@@ -127,16 +133,3 @@ END;
 $body$
 LANGUAGE plpgsql IMMUTABLE STRICT PARALLEL SAFE;
 
-CREATE OR REPLACE FUNCTION sys.nchar(IN x varbinary) RETURNS sys.nvarchar
-AS
-$body$
-BEGIN
-    --- 1114111 is 0x10FFFF - max value permitted as specified by documentation
-    if x::integer between 1 and 1114111 then
-        return(select chr(x::integer))::sys.nvarchar;
-    else
-        return null;
-    end if;
-END;
-$body$
-LANGUAGE plpgsql IMMUTABLE STRICT PARALLEL SAFE;

contrib/babelfishpg_common/sql/upgrades/babelfish_common_helper--5.2.0--5.3.0.sql

@@ -7,6 +7,36 @@
 
 SELECT set_config('search_path', 'sys, '||current_setting('search_path'), false);
 
+-- Drops an object if it does not have any dependent objects.
+-- Is a temporary procedure for use by the upgrade script. Will be dropped at the end of the upgrade.
+-- Please have this be one of the first statements executed in this upgrade script. 
+CREATE OR REPLACE PROCEDURE babelfish_drop_deprecated_object(object_type varchar, schema_name varchar, object_name varchar) AS
+$$
+DECLARE
+    error_msg text;
+    query1 text;
+    query2 text;
+BEGIN
+
+    query1 := pg_catalog.format('alter extension babelfishpg_common drop %s %s.%s', object_type, schema_name, object_name);
+    query2 := pg_catalog.format('drop %s %s.%s', object_type, schema_name, object_name);
+
+    execute query1;
+    execute query2;
+EXCEPTION
+    when object_not_in_prerequisite_state then --if 'alter extension' statement fails
+        GET STACKED DIAGNOSTICS error_msg = MESSAGE_TEXT;
+        raise warning '%', error_msg;
+    when dependent_objects_still_exist then --if 'drop view' statement fails
+        GET STACKED DIAGNOSTICS error_msg = MESSAGE_TEXT;
+        raise warning '%', error_msg;
+    when undefined_function then --if 'Deprecated function does not exist'
+        GET STACKED DIAGNOSTICS error_msg = MESSAGE_TEXT;
+        raise warning '%', error_msg;
+end
+$$
+LANGUAGE plpgsql;
+
 -- casting from bytea to binary
 CREATE OR REPLACE FUNCTION sys.byteabinary(pg_catalog.BYTEA, integer, boolean)
 RETURNS sys.BBF_BINARY
@@ -145,6 +175,87 @@ BEGIN
     END IF;
 END $$;
 
+DO $$
+DECLARE
+    exception_message text;
+BEGIN
+    ALTER FUNCTION sys.char(x in int) RENAME TO chr_deprecated_5_3_0;
+
+EXCEPTION WHEN OTHERS THEN
+    GET STACKED DIAGNOSTICS
+    exception_message = MESSAGE_TEXT;
+    RAISE WARNING '%', exception_message;
+END;
+$$;
+
+CALL sys.babelfish_drop_deprecated_object('function', 'sys', 'chr_deprecated_5_3_0');
+
+DO $$
+DECLARE
+    exception_message text;
+BEGIN
+   ALTER FUNCTION sys.nchar(In x INTEGER) RENAME TO nchar_int_deprecated_5_3_0;
+
+EXCEPTION WHEN OTHERS THEN
+    GET STACKED DIAGNOSTICS
+    exception_message = MESSAGE_TEXT;
+    RAISE WARNING '%', exception_message;
+END;
+$$;
+
+CALL sys.babelfish_drop_deprecated_object('function', 'sys', 'nchar_int_deprecated_5_3_0');
+
+DO $$
+DECLARE
+    exception_message text;
+BEGIN
+   ALTER FUNCTION sys.nchar(In x varbinary) RENAME TO nchar_varbinary_deprecated_5_3_0;
+
+EXCEPTION WHEN OTHERS THEN
+    GET STACKED DIAGNOSTICS
+    exception_message = MESSAGE_TEXT;
+    RAISE WARNING '%', exception_message;
+END;
+$$;
+
+CALL sys.babelfish_drop_deprecated_object('function', 'sys', 'nchar_varbinary_deprecated_5_3_0');
+
+create or replace function sys.cht_(x in int) returns sys.varchar
+AS
+$body$
+BEGIN
+/***************************************************************
+EXTENSION PACK function CHAR(x)
+***************************************************************/
+    if x = 0 then 
+        return ('\x00'::bytea)::sys.varbinary;
+    end if;
+    if x between 1 and 255 then
+        return chr(x);
+    else
+        return null;
+    end if;
+END;
+$body$
+LANGUAGE plpgsql IMMUTABLE STRICT PARALLEL SAFE;
+
+CREATE OR REPLACE FUNCTION sys.ncht_(x in int) RETURNS sys.nvarchar
+AS
+$body$
+BEGIN
+    if x = 0 then 
+        return ('\x00'::bytea)::sys.varbinary;
+    end if;
+    --- 65535 is 0x0000FFFF - max value permitted as specified by documentation without SC collation
+    if x between 1 and 65535 then
+        return(select chr(x))::sys.nvarchar;
+    else
+        return null;
+    end if;
+END;
+$body$
+LANGUAGE plpgsql IMMUTABLE STRICT PARALLEL SAFE;
+
 -- arithmetic functions where one of the 
 -- operand is smallmoney
 
@@ -669,5 +780,9 @@ BEGIN
 	END IF;
 END $$;
 
+-- 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);
+
 -- 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_tsql/src/tsqlIface.cpp

@@ -3004,6 +3004,33 @@ class tsqlMutator : public TSqlParserBaseListener
     {
     }
 
+private:
+    void handleCharNcharTypeRename(const std::string &procNameStr, TSqlParser::IdContext *proc, 
+				TSqlParser::IdContext *schema)
+    {
+
+	int startIndex = proc->start->getStartIndex();
+	std::string alias;
+	std::string formattedName;
+
+	if (pg_strcasecmp(procNameStr.c_str(), "char") == 0)
+		alias = "cht_";
+	else if (pg_strcasecmp(procNameStr.c_str(), "nchar") == 0)
+		alias = "ncht_";
+
+	if(schema && pg_strcasecmp(stripQuoteFromId(schema).c_str(), "sys") != 0)
+		return;
+
+	if (proc->DOUBLE_QUOTE_ID())
+		formattedName = "\"" + alias + "\"";
+	else if (proc->SQUARE_BRACKET_ID())
+		formattedName = "[" + alias + "]";
+	else
+		formattedName = alias;
+
+	stream.setText(startIndex, formattedName.c_str());
+    }
+
 public:
     void enterFunc_proc_name_schema(TSqlParser::Func_proc_name_schemaContext *ctx) override
     {	
@@ -3014,6 +3041,7 @@ class tsqlMutator : public TSqlParserBaseListener
 	// "char" is a data type name in PostgreSQL
 
 	TSqlParser::IdContext *proc = ctx->procedure;
+	TSqlParser::IdContext *schema = ctx->schema;
 
 	//  According to the grammar, an id can be any of the following:
 	//
@@ -3032,17 +3060,11 @@ class tsqlMutator : public TSqlParserBaseListener
 	if (proc->keyword() || proc->colon_colon())
 	    return;
 
-	// FIXME: handle the schema here too
 	std::string procNameStr = getIDName(proc->DOUBLE_QUOTE_ID(), proc->SQUARE_BRACKET_ID(), proc->ID());
 
-	if (pg_strcasecmp(procNameStr.c_str(), "char") ==  0)
+	if (pg_strcasecmp(procNameStr.c_str(), "char") == 0 || pg_strcasecmp(procNameStr.c_str(), "nchar") == 0)
 	{
-	    if (proc->DOUBLE_QUOTE_ID())
-		stream.setText(ctx->start->getStartIndex(), "\"chr\" ");
-	    else if (proc->SQUARE_BRACKET_ID())
-		stream.setText(ctx->start->getStartIndex(), "[chr] ");		
-	    else
-		stream.setText(ctx->start->getStartIndex(), " chr");
+		handleCharNcharTypeRename(procNameStr, proc, schema);
 	}
     }	
 
@@ -3140,6 +3162,7 @@ class tsqlMutator : public TSqlParserBaseListener
 	// "char" is a data type name in PostgreSQL
 
 	TSqlParser::IdContext *proc = ctx->procedure;
+	TSqlParser::IdContext *schema = ctx->schema;
 
 	#ifdef ENABLE_SPATIAL_TYPES
 	if(!ctx->id().empty() && ctx->id()[0]->id().size() == 2)
@@ -3176,17 +3199,11 @@ class tsqlMutator : public TSqlParserBaseListener
 	if (proc->keyword() || proc->colon_colon())
 	    return;
 
-	// FIXME: handle the schema here too
 	std::string procNameStr = getIDName(proc->DOUBLE_QUOTE_ID(), proc->SQUARE_BRACKET_ID(), proc->ID());
 
-	if (pg_strcasecmp(procNameStr.c_str(), "char") ==  0)
+	if (pg_strcasecmp(procNameStr.c_str(), "char") == 0 || pg_strcasecmp(procNameStr.c_str(), "nchar") == 0)
 	{
-	    if (proc->DOUBLE_QUOTE_ID())
-		stream.setText(ctx->start->getStartIndex(), "\"chr\" ");
-	    else if (proc->SQUARE_BRACKET_ID())
-		stream.setText(ctx->start->getStartIndex(), "[chr] ");		
-	    else
-		stream.setText(ctx->start->getStartIndex(), " chr");
+		handleCharNcharTypeRename(procNameStr, proc, schema);
 	}
     }
 

test/JDBC/expected/ascii.out

@@ -127,9 +127,10 @@ int#!#int#!#int#!#int
 -- following throws error in babelfish
 SELECT ASCII(CHAR(0)) AS NullChar
 GO
-~~ERROR (Code: 33557097)~~
-
-~~ERROR (Message: null character not permitted)~~
+~~START~~
+int
+0
+~~END~~
 
 
 -- 4. Tests with Different Data Types
@@ -238,7 +239,7 @@ SELECT
 GO
 ~~START~~
 int#!#int
-256#!#12121
+<NULL>#!#<NULL>
 ~~END~~
 
 
@@ -262,7 +263,7 @@ SELECT
 FROM Numbers;
 GO
 ~~START~~
-int#!#text#!#int#!#varchar
+int#!#varchar#!#int#!#varchar
 1#!#
#!#1#!#Pass
 2#!##!#2#!#Pass
 3#!##!#3#!#Pass
@@ -712,7 +713,7 @@ EXEC ascii_sp_analyzestring 'Test String';
 EXEC ascii_sp_validateascii 'A', 65;
 GO
 ~~START~~
-varchar#!#int#!#text#!#varchar
+varchar#!#int#!#varchar#!#varchar
 Test String#!#84#!#T#!#Uppercase
 ~~END~~
 

test/JDBC/expected/babel_726-before-14_12-or-15_7-or-16_3-vu-verify.out

@@ -34,7 +34,7 @@ int
 select coalesce(NULL, CHAR(9))
 go
 ~~START~~
-text
+varchar
 
 ~~END~~
 

test/JDBC/expected/babel_726-vu-verify.out

@@ -34,7 +34,7 @@ int
 select coalesce(NULL, CHAR(9))
 go
 ~~START~~
-text
+varchar
 
 ~~END~~
 

test/JDBC/expected/babel_726.out

@@ -34,7 +34,7 @@ int
 select coalesce(NULL, CHAR(9))
 go
 ~~START~~
-text
+varchar
 
 ~~END~~
 

test/JDBC/expected/babel_char-vu-verify.out

@@ -37,12 +37,12 @@ select nchar(0x10FFFF);
 GO
 ~~START~~
 nvarchar
-􏿿
+<NULL>
 ~~END~~
 
 ~~START~~
 nvarchar
-􏿿
+<NULL>
 ~~END~~
 
 
@@ -61,6 +61,25 @@ nvarchar
 <NULL>
 ~~END~~
 
+~~START~~
+nvarchar
+
+~~END~~
+
+~~START~~
+nvarchar
+<NULL>
+~~END~~
+
+select sys.nchar(65535)
+select sys.nchar(65536)
+select sys.nchar(-1)
+GO
+~~START~~
+nvarchar
+￿
+~~END~~
+
 ~~START~~
 nvarchar
 <NULL>