Bug #3481 wrong syntax (last comma) does not return syntax error

• Submitted: 15 Apr 2004 23:44
• Modified: 28 Apr 2004 16:42
• Reporter: Thomas Mayer
• Status: Closed
• Category: MySQL Server
• Severity: S3 (Non-critical)
• Version: 4.0.18
• OS: Linux (Suse Linux 8.2)
• Assigned to: Antony Curtis
• CPU Architecture: Any

[15 Apr 2004 23:44] Thomas Mayer

Description:
In case a comma is left before the field-list brackets close in a create table statement, MySQL does not return a syntax error.

How to repeat:
-- right syntax:
create table test (
myfield tinyint(2),
);

-- wrong syntax:
create table test (
myfield tinyint(2),
);
-- but works as well ;-)

Suggested fix:
check wether the syntax is correct or not...

[15 Apr 2004 23:59] Thomas Mayer

-- and even totally wrong:
create table test2 (
myfield tinyint(2),,,
myfield2 tinyint(2),,,,,
,,, , );
-- that's funny :-)

[16 Apr 2004 0:01] Thomas Mayer

-- The right syntax should of course be
create table test (
myfield tinyint(2)
);

[16 Apr 2004 1:21] Marko Mäkelä

According to ISO/IEC 9075-2:2003, trailing commas are not allowed:

<table element list> ::=
  <left paren> <table element> [ { <comma> <table element> }... ] <right paren>

[19 Apr 2004 8:48] Antony Curtis

The following patch fixes the behaviour. 
 
===== sql/sql_yacc.yy 1.227 vs edited ===== 
--- 1.227/sql/sql_yacc.yy	Wed Mar 10 09:50:15 2004 
+++ edited/sql/sql_yacc.yy	Mon Apr 19 17:16:33 2004 
@@ -945,7 +945,7 @@ 
          ; 
  
 column_def: 
-	  field_spec check_constraint 
+	  field_spec opt_check_constraint 
 	| field_spec references 
 	  { 
 	    Lex->col_list.empty();		/* Alloced by sql_alloc */ 
@@ -963,20 +963,31 @@ 
 	  { 
 	    Lex->col_list.empty();		/* Alloced by sql_alloc */ 
 	  } 
+	| constraint opt_check_constraint 
+	  { 
+	    Lex->col_list.empty();		/* Alloced by sql_alloc */ 
+	  } 
 	| opt_constraint check_constraint 
 	  { 
 	    Lex->col_list.empty();		/* Alloced by sql_alloc */ 
 	  } 
 	; 
  
-check_constraint: 
+opt_check_constraint: 
 	/* empty */ 
-	| CHECK_SYM expr 
+	| check_constraint 
+	; 
+ 
+check_constraint: 
+	CHECK_SYM expr 
 	; 
  
 opt_constraint: 
 	/* empty */ 
-	| CONSTRAINT opt_ident; 
+	| constraint; 
+	 
+constraint: 
+	CONSTRAINT opt_ident; 
  
 field_spec: 
 	field_ident

[28 Apr 2004 10:27] Michael Widenius

Antony, don't forget to add a test case for this

[28 Apr 2004 16:42] Antony Curtis

Thank you for your bug report. This issue has been committed to our
source repository of that product and will be incorporated into the
next release.

If necessary, you can access the source repository and build the latest
available version, including the bugfix, yourself. More information 
about accessing the source trees is available at
    http://www.mysql.com/doc/en/Installing_source_tree.html

Additional info:

Patch + testcase pushed into 4.0 repository