MDEV-11439 No data type JSON, but CAST(something AS JSON) pretends to work

Use JSON_COMPACT(X) instead of CAST(X AS JSON).
Bonus - X is validated to be a valid JSON.
Fix a typo in the error message.

1 files changed, 2 insertions, 13 deletions

diff --git a/sql/item_jsonfunc.h b/sql/item_jsonfunc.h
index 0eedfa18be1..535f1bf73a5 100644
--- a/sql/item_jsonfunc.h
+++ b/sql/item_jsonfunc.h
@@ -414,19 +414,6 @@ public:
 };
 
 
-class Item_json_typecast: public Item_str_func
-{
-public:
-  Item_json_typecast(THD *thd, Item *a): Item_str_func(thd, a) {}
-  const char *func_name() const { return "cast_as_json"; }
-  bool is_json_type() { return true; }
-  void fix_length_and_dec();
-  String *val_str(String *str);
-  Item *get_copy(THD *thd, MEM_ROOT *mem_root)
-  { return get_item_copy<Item_json_typecast>(thd, mem_root, this); }
-};
-
-
 class Item_func_json_format: public Item_str_func
 {
 public:
@@ -449,6 +436,8 @@ public:
   const char *func_name() const;
   void fix_length_and_dec();
   String *val_str(String *str);
+  String *val_json(String *str);
+  bool is_json_type() { return true; }
   Item *get_copy(THD *thd, MEM_ROOT *mem_root)
   { return get_item_copy<Item_func_json_format>(thd, mem_root, this); }
 };