[Feature] Issue#61 new built-in function to let customer manually issue an error

AliSQL · AliSQL · commit 66c68db51483 · 2018-05-01T15:34:10.000+08:00
A new built-in function RAISE_ERROR('diagnostic-string') is needed to
let mysql users fail current statement with the desired
diagnostic-string error message and reserved sql error code.

DB2 does in its' RAISE_ERROR() function, where the function accepts
parameters of sql state and msg, and Oracle's RAISE_APPLICATION_ERROR
has similar function.

In our implementation, raise_error() accepts parameter of msg and
optional sql state, both are strings. NULL value input is not allowed
for either one, and only validate sql state is allowed.

Here are samples:

--error ER_SP_BAD_SQLSTATE

select raise_error(NULL, 'null sql state not allowed');

--error ER_MALFORMED_MESSAGE select raise_error('70001', NULL);

--error ER_SP_BAD_SQLSTATE

select raise_error('00001', 'invalid sql state');

--error ER_SP_BAD_SQLSTATE

select raise_error('666666', 'length of sql state exceeds 5');

--error ER_INTENTIONAL_ERROR

select raise_error('70001', 'this is a sample error msg');

--error ER_INTENTIONAL_ERROR

select raise_error('this is a sample error msg');

--error ER_INTENTIONAL_ERROR
select raise_error('only error message applied');
diff --git a/mysql-test/suite/rds/r/feature_raise_error_issue679.result b/mysql-test/suite/rds/r/feature_raise_error_issue679.result
@@ -0,0 +1,18 @@
+select raise_error(NULL, 'this is a sample error msg');
+ERROR 42000: Bad SQLSTATE: 'NULL'
+select raise_error('70001', NULL);
+ERROR HY000: Malformed message specification 'NULL'.
+select raise_error('00001', 'this is a sample error msg');
+ERROR 42000: Bad SQLSTATE: '00001'
+select raise_error('666666', 'length of sql state exceeds 5');
+ERROR 42000: Bad SQLSTATE: '666666'
+select raise_error('70001', 'this is a sample error msg');
+ERROR 70001: this is a sample error msg
+select raise_error('this is a sampel error msg');
+ERROR HY000: this is a sampel error msg
+select raise_error('HY000', 'this is a sample error msg');
+ERROR HY000: this is a sample error msg
+select raise_error('08S01', 'this is a sample error msg');
+ERROR 08S01: this is a sample error msg
+select raise_error('only error message applied');
+ERROR HY000: only error message applied
diff --git a/mysql-test/suite/rds/t/feature_raise_error_issue679.test b/mysql-test/suite/rds/t/feature_raise_error_issue679.test
@@ -0,0 +1,25 @@
+#sql state not allowed to be null
+--error ER_SP_BAD_SQLSTATE
+select raise_error(NULL, 'this is a sample error msg');
+
+#error msg not allowed to be null
+--error ER_MALFORMED_MESSAGE
+select raise_error('70001', NULL);
+
+#invalid sql state
+--error ER_SP_BAD_SQLSTATE
+select raise_error('00001', 'this is a sample error msg');
+--error ER_SP_BAD_SQLSTATE
+select raise_error('666666', 'length of sql state exceeds 5');
+
+#valid input
+--error ER_INTENTIONAL_ERROR
+select raise_error('70001', 'this is a sample error msg');
+--error ER_INTENTIONAL_ERROR
+select raise_error('this is a sampel error msg');
+--error ER_INTENTIONAL_ERROR
+select raise_error('HY000', 'this is a sample error msg');
+--error ER_INTENTIONAL_ERROR
+select raise_error('08S01', 'this is a sample error msg');
+--error ER_INTENTIONAL_ERROR
+select raise_error('only error message applied');
diff --git a/sql/item_create.cc b/sql/item_create.cc
@@ -2090,7 +2090,6 @@ class Create_func_quote : public Create_func_arg1
   virtual ~Create_func_quote() {}
 };
 
-
 class Create_func_radians : public Create_func_arg1
 {
 public:
@@ -2103,6 +2102,17 @@ class Create_func_radians : public Create_func_arg1
   virtual ~Create_func_radians() {}
 };
 
+class Create_func_raise_error : public Create_native_func
+{
+public:
+  virtual Item *create_native(THD *thd, LEX_STRING name,
+            List<Item> *item_list);
+
+  static Create_func_raise_error s_singleton;
+protected:
+  Create_func_raise_error() {}
+  virtual ~Create_func_raise_error() {}
+};
 
 class Create_func_rand : public Create_native_func
 {
@@ -4853,6 +4863,42 @@ Create_func_radians::create(THD *thd, Item *arg1)
                                              M_PI/180, 0.0);
 }
 
+Create_func_raise_error Create_func_raise_error::s_singleton;
+
+Item*
+Create_func_raise_error::create_native(THD *thd, LEX_STRING name,
+                                       List<Item> *item_list)
+{
+  Item *func= NULL;
+  int arg_count= 0;
+
+  if (item_list != NULL)
+    arg_count= item_list->elements;
+
+  switch (arg_count) {
+  case 1:
+  {
+    Item *param_1= item_list->pop();
+    func= new (thd->mem_root) Item_func_raise_error(param_1);
+    break;
+  }
+  case 2:
+  {
+    Item *param_1= item_list->pop();
+    Item *param_2= item_list->pop();
+    func= new (thd->mem_root) Item_func_raise_error(param_1, param_2);
+    break;
+  }
+  default:
+  {
+    my_error(ER_WRONG_PARAMCOUNT_TO_NATIVE_FCT, MYF(0), name.str);
+    break;
+  }
+  }
+
+  return func;
+}
+
 
 Create_func_rand Create_func_rand::s_singleton;
 
@@ -5627,6 +5673,7 @@ static Native_func_registry func_array[] =
   { { C_STRING_WITH_LEN("POWER") }, BUILDER(Create_func_pow)},
   { { C_STRING_WITH_LEN("QUOTE") }, BUILDER(Create_func_quote)},
   { { C_STRING_WITH_LEN("RADIANS") }, BUILDER(Create_func_radians)},
+  { { C_STRING_WITH_LEN("RAISE_ERROR") }, BUILDER(Create_func_raise_error)},
   { { C_STRING_WITH_LEN("RAND") }, BUILDER(Create_func_rand)},
   { { C_STRING_WITH_LEN("RANDOM_BYTES") }, BUILDER(Create_func_random_bytes) },
   { { C_STRING_WITH_LEN("RELEASE_LOCK") }, BUILDER(Create_func_release_lock) },
diff --git a/sql/item_func.cc b/sql/item_func.cc
@@ -552,6 +552,70 @@ my_decimal *Item_func::val_decimal(my_decimal *decimal_value)
   return decimal_value;
 }
 
+/*
+  Raise an error with specified error message and optional sql state,
+  sql error code is ER_INTENTIONAL_ERROR.
+*/
+longlong Item_func_raise_error::val_int()
+{
+  DBUG_ENTER("Item_raise_error::val_int");
+  DBUG_ASSERT(fixed == 1);
+
+  THD* thd= current_thd;
+
+  String *sql_state= NULL;
+  String *msg= NULL;
+
+  if (arg_count == 2)
+  // both sql state and error message are specified
+  {
+    sql_state= args[0]->val_str(&value);
+    // validate sql_state input
+    if (sql_state == NULL)
+    {
+      my_error(ER_SP_BAD_SQLSTATE, MYF(0), "NULL");
+      DBUG_RETURN(0);
+    }
+
+    LEX_STRING lex_sql_state= sql_state->lex_string();
+
+    if (!is_sqlstate_valid(&lex_sql_state) || is_sqlstate_completion(sql_state->ptr()))
+    {
+      my_error(ER_SP_BAD_SQLSTATE, MYF(0), sql_state->ptr());
+      DBUG_RETURN(0);
+    }
+    msg= args[1]->val_str(&value);
+    // validate message input
+    if (msg == NULL)
+    {
+      my_error(ER_MALFORMED_MESSAGE, MYF(0), "NULL");
+      DBUG_RETURN(0);
+    }
+
+    // raise the manual error now
+    (void) thd->raise_error(ER_INTENTIONAL_ERROR,
+                            sql_state->ptr(),
+                            msg->ptr());
+
+    DBUG_RETURN(0);
+  }
+  else
+  // only error message is specified
+  {
+    msg= args[0]->val_str(&value);
+    // validate message input
+    if (msg == NULL)
+    {
+      my_error(ER_MALFORMED_MESSAGE, MYF(0), "NULL");
+      DBUG_RETURN(0);
+    }
+    // raise the manual error now
+    (void) thd->raise_error(ER_INTENTIONAL_ERROR,
+                            NULL,
+                            msg->ptr());
+    DBUG_RETURN(0);
+  }
+}
 
 String *Item_real_func::val_str(String *str)
 {
diff --git a/sql/item_func.h b/sql/item_func.h
@@ -904,6 +904,22 @@ class Item_func_round :public Item_func_num1
   void fix_length_and_dec();
 };
 
+/**
+  This class is used for implementing the new raise_error function and the functions related to them.
+*/
+class Item_func_raise_error :public Item_int_func
+{
+
+  String value;
+public:
+  Item_func_raise_error( Item *a) :Item_int_func(a) {}
+  Item_func_raise_error( Item *a, Item *b)
+    :Item_int_func(a, b)
+  {}
+
+  longlong val_int();
+  const char *func_name() const {return "raise_error";}
+};
 
 class Item_func_rand :public Item_real_func
 {
diff --git a/sql/share/errmsg-utf8.txt b/sql/share/errmsg-utf8.txt
@@ -7142,4 +7142,7 @@ ER_SEQUENCE_NOT_DEFINED
   eng "Sequence '%-.192s.%-.192s' is not yet defined in this session"
 ER_NOT_SEQUENCE
   eng "'%-.192s.%-.192s' is not a SEQUENCE"
-
+ER_MALFORMED_MESSAGE
+  eng "Malformed message specification '%.200s'."
+ER_INTENTIONAL_ERROR
+  eng "user issue an error intentionally."
diff --git a/sql/sql_class.cc b/sql/sql_class.cc
@@ -1234,6 +1234,16 @@ void THD::raise_error(uint sql_errno)
                          msg);
 }
 
+void THD::raise_error(uint sql_errno,
+                      const char* sql_state,
+                      const char* msg)
+{
+  (void) raise_condition(sql_errno,
+                         sql_state,
+                         Sql_condition::WARN_LEVEL_ERROR,
+                         msg);
+}
+
 void THD::raise_error_printf(uint sql_errno, ...)
 {
   va_list args;
diff --git a/sql/sql_class.h b/sql/sql_class.h
@@ -4192,6 +4192,13 @@ class THD :public MDL_context_owner,
   */
   void raise_note_printf(uint code, ...);
 
+  /**
+    Raise an exception condition with specified msg
+  */
+  void raise_error(uint sql_errno,
+                   const char* sqlstate,
+                   const char* msg);
+
 private:
   /*
     Only the implementation of the SIGNAL and RESIGNAL statements
