Update function signature for OBJECT_DEFINITION (#3814)

Currently OBJECT_DEFINITION function return type is defined as sys.NVARCHAR(4000). This limits the object definition being return to 4000 bytes pair. This PR removes this limitation.

Task: BABEL-5057

Signed-off-by: Shard Gupta <shardga@amazon.com>

Author: shardgupta

contrib/babelfishpg_tsql/sql/sys_functions.sql

@@ -4408,11 +4408,11 @@ RETURNS sys.SYSNAME AS
 'babelfishpg_tsql', 'object_schema_name'
 LANGUAGE C STABLE;
 
-CREATE OR REPLACE FUNCTION OBJECT_DEFINITION(IN object_id INT)
-RETURNS sys.NVARCHAR(4000)
+CREATE OR REPLACE FUNCTION sys.OBJECT_DEFINITION(IN object_id INT)
+RETURNS sys.NVARCHAR
 AS $$
 DECLARE
-    definition sys.nvarchar(4000);
+    definition sys.NVARCHAR;
 BEGIN
 
     definition = (SELECT cc.definition FROM sys.check_constraints cc WHERE cc.object_id = $1);

contrib/babelfishpg_tsql/sql/upgrades/babelfishpg_tsql--5.2.0--5.3.0.sql

@@ -764,6 +764,31 @@ WHERE sch.nspname = t.typnamespace::regnamespace::name
 	AND t.typtypmod = -1
 	AND t.typtype = 'd';
 
+CREATE OR REPLACE FUNCTION sys.OBJECT_DEFINITION(IN object_id INT)
+RETURNS sys.NVARCHAR
+AS $$
+DECLARE
+    definition sys.NVARCHAR;
+BEGIN
+
+    definition = (SELECT cc.definition FROM sys.check_constraints cc WHERE cc.object_id = $1);
+    IF (definition IS NULL)
+    THEN
+        definition = (SELECT dc.definition FROM sys.default_constraints dc WHERE dc.object_id = $1);
+        IF (definition IS NULL)
+        THEN
+            definition = (SELECT asm.definition FROM sys.all_sql_modules asm WHERE asm.object_id = $1);
+            IF (definition IS NULL)
+            THEN
+                RETURN NULL;
+            END IF;
+        END IF;
+    END IF;
+
+    RETURN definition;
+END;
+$$
+LANGUAGE plpgsql STABLE;
 create or replace function sys.PATINDEX(in pattern varchar, in expression varchar) returns bigint as
 $body$
 declare

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

@@ -51,3 +51,19 @@ DROP PROCEDURE if exists object_definition_procedure;
 GO
 DROP FUNCTION if exists object_definition_function();
 GO
+
+-- Clean up
+DROP FUNCTION dbo.object_definition_LargeFunction
+GO
+DROP VIEW dbo.object_definition_LargeView
+GO
+DROP PROCEDURE dbo.object_definition_Largeproc
+GO
+DROP VIEW dbo.object_definition_dependency_view
+GO
+DROP PROCEDURE dbo.object_definition_dependency_proc
+GO
+DROP FUNCTION dbo.object_definition_dependency_func
+GO
+DROP PROCEDURE dbo.object_definition_dependent_proc
+GO

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

@@ -50,4 +50,20 @@ GO
 DROP PROCEDURE if exists object_definition_procedure;
 GO
 DROP FUNCTION if exists object_definition_function();
-GO
+GO
+
+-- Clean up
+DROP FUNCTION dbo.object_definition_LargeFunction
+GO
+DROP VIEW dbo.object_definition_LargeView
+GO
+DROP PROCEDURE dbo.object_definition_Largeproc
+GO
+DROP VIEW dbo.object_definition_dependency_view
+GO
+DROP PROCEDURE dbo.object_definition_dependency_proc
+GO
+DROP FUNCTION dbo.object_definition_dependency_func
+GO
+DROP PROCEDURE dbo.object_definition_dependent_proc
+GO

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

@@ -132,4 +132,38 @@ go
 ALTER function object_definition_function() RETURNS [VARCHAR](6000) AS BEGIN DECLARE @storeOriginalQuery_var [varchar] (6000) RETURN @storeOriginalQuery_var END
 go
 SELECT ROUTINE_DEFINITION FROM INFORMATION_SCHEMA.ROUTINES WHERE ROUTINE_NAME = 'object_definition_function';
-go
+go
+
+-- Test OBJECT_DEFINITION on the large stored procedure
+SELECT LEN(OBJECT_DEFINITION(OBJECT_ID('dbo.object_definition_Largeproc'))) AS DefinitionLength
+GO
+
+SELECT OBJECT_DEFINITION(OBJECT_ID('dbo.object_definition_Largeproc'))
+GO
+
+-- Test OBJECT_DEFINITION on the large view
+SELECT LEN(OBJECT_DEFINITION(OBJECT_ID('dbo.object_definition_LargeView'))) AS DefinitionLength
+GO
+
+SELECT OBJECT_DEFINITION(OBJECT_ID('dbo.object_definition_LargeView'))
+GO
+
+-- Test OBJECT_DEFINITION on the large function
+SELECT LEN(OBJECT_DEFINITION(OBJECT_ID('dbo.object_definition_LargeFunction'))) AS DefinitionLength
+GO
+
+SELECT OBJECT_DEFINITION(OBJECT_ID('dbo.object_definition_LargeFunction'))
+GO
+
+-- Test the dependency view
+SELECT * FROM dbo.object_definition_dependency_view WHERE name = 'dbo.object_definition_dependent_proc'
+GO
+
+-- Test the new dependency procedure
+EXEC dbo.object_definition_dependency_proc 'dbo.object_definition_dependent_proc'
+GO
+
+-- Test the dependency function
+SELECT dbo.object_definition_dependency_func('dbo.object_definition_dependent_proc') AS FunctionResult
+GO
+