Support PRINT NULL and PRINT <empty string> (babelfish-for-postgresql…

…#2199)

This PR introduces support for printing NULL and <empty string>. When the argument to PRINT is NULL or an empty string, a single space should be printed. However Babelfish currently prints <NULL> and an empty string, respectively.

Signed-off-by: Rob Verschoor [email protected]

contrib/babelfishpg_tsql/src/pl_exec-2.c

@@ -410,11 +410,22 @@ exec_stmt_print(PLtsql_execstate *estate, PLtsql_stmt_print *stmt)
 								 &formattypmod);
 
 	if (formatisnull)
-		extval = "<NULL>";
+	{
+		// Printing NULL prints a single space in T-SQL 
+		extval = " ";
+	}
 	else
+	{
 		extval = convert_value_to_string(estate,
 										 formatdatum,
 										 formattypeid);
+	}
+
+	if (strlen(extval) == 0)
+	{
+		// Printing an empty string prints a single space in T-SQL
+		extval = " ";
+	}
 
 	ereport(INFO, errmsg_internal("%s", extval));
 

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

@@ -0,0 +1,2 @@
+drop procedure p1_print_null
+go

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

@@ -0,0 +1,10 @@
+create procedure p1_print_null as
+declare @v varchar = null
+print null
+print @v
+print ''
+set @v = ''
+print @v
+print ' '
+print '  '
+go

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

@@ -0,0 +1,31 @@
+
+-- Since the JDBC tests do not capture output from PRINT statements, these tests actually don't do anything
+-- Keeping them for when then moment comes that PRINT tests are supported
+-- prints a single space:
+print null
+go
+
+-- prints a single space:
+declare @v varchar = null
+print @v
+go
+-- prints a single space:
+print ''
+go
+
+-- prints a single space:
+declare @v varchar = ''
+print @v
+go
+
+-- prints a single space:
+print ' '
+go
+
+-- prints two spaces:
+print '  '
+go
+
+-- same set of tests as above, but inside a stored proc:
+exec p1_print_null
+go

test/JDBC/input/print_null-vu-cleanup.sql

@@ -0,0 +1,2 @@
+drop procedure p1_print_null
+go

test/JDBC/input/print_null-vu-prepare.sql

@@ -0,0 +1,10 @@
+create procedure p1_print_null as
+declare @v varchar = null
+print null
+print @v
+print ''
+set @v = ''
+print @v
+print ' '
+print '  '
+go

test/JDBC/input/print_null-vu-verify.sql

@@ -0,0 +1,31 @@
+-- Since the JDBC tests do not capture output from PRINT statements, these tests actually don't do anything
+-- Keeping them for when then moment comes that PRINT tests are supported
+
+-- prints a single space:
+print null
+go
+
+-- prints a single space:
+declare @v varchar = null
+print @v
+go
+-- prints a single space:
+print ''
+go
+
+-- prints a single space:
+declare @v varchar = ''
+print @v
+go
+
+-- prints a single space:
+print ' '
+go
+
+-- prints two spaces:
+print '  '
+go
+
+-- same set of tests as above, but inside a stored proc:
+exec p1_print_null
+go

test/JDBC/upgrade/latest/schedule

@@ -462,6 +462,7 @@ todatetimeoffset-dep
 triggers_with_transaction
 typeid-typename
 typeid-typename-dep
+print_null
 unquoted_string
 doublequoted_string
 alter_authorization_change_db_owner