fix charset (#736)

src/sql/parser/sql_parser_mysql_mode.y

@@ -4380,6 +4380,15 @@ BINARY opt_string_length_i_v2
   $$->int32_values_[OB_NODE_CAST_C_LEN_IDX] = $2[0];        /* length */
   $$->param_num_ = $2[1];
 }
+| CHARACTER opt_string_length_i_v2 CHARACTER SET charset_name 
+{
+  malloc_terminal_node($$, result->malloc_pool_, T_CAST_ARGUMENT);
+  $$->value_ = 0;
+  $$->int16_values_[OB_NODE_CAST_TYPE_IDX] = T_CHAR; /* data type */
+  $$->param_num_ = $2[1];
+  $$->str_value_ = $5->str_value_;
+  $$->str_len_ = $5->str_len_;
+}
 | cast_datetime_type_i opt_datetime_fsp_i
 {
   malloc_terminal_node($$, result->malloc_pool_, T_CAST_ARGUMENT);
@@ -14577,4 +14586,4 @@ int obsql_mysql_fast_parse(ParseResult *p)
     p->no_param_sql_[len] = '\0';
   }
   return ret;
-}
+}

src/sql/resolver/expr/ob_raw_expr_resolver_impl.cpp

@@ -318,8 +318,23 @@ int ObRawExprResolverImpl::do_recursive_resolve(const ParseNode* node, ObRawExpr
             } else if (ob_is_extend(data_type)) {
               ret = OB_NOT_SUPPORTED;
             }
+
             if (OB_SUCC(ret)) {
-              val.set_int(node->value_);
+              if (node->str_value_) {
+                ObString cs_name = ObString(node->str_value_);
+                ObCharsetType charset_type = CHARSET_INVALID;
+                if (CHARSET_INVALID == (charset_type = ObCharset::charset_type(cs_name.trim()))) {
+                  ret = OB_ERR_UNKNOWN_CHARSET;
+                  LOG_WARN("unknown charset", K(ret), K(cs_name));
+                } else {
+                  ParseNode tmp_node;
+                  tmp_node.value_ = node->value_;
+                  tmp_node.int16_values_[OB_NODE_CAST_COLL_IDX] = ObCharset::get_default_collation(charset_type);
+                  val.set_int(tmp_node.value_);
+                }
+              } else {
+                val.set_int(node->value_);
+              }
               c_expr->set_value(val);
               c_expr->set_param(val);
               expr = c_expr;

test/mysql_test/test_suite/expr/r/mysql/collation_expr.result

@@ -501,4 +501,10 @@ utf8mb4_bin
 select collation(cast('A' as char)), cast('A' as char) < 'a';
 collation(cast('A' as char))	cast('A' as char) < 'a'
 utf8mb4_bin	1
+SELECT collation(CAST('A' AS char CHAR SET utf8mb4));
+collation(CAST('A' AS char CHAR SET utf8mb4))
+utf8mb4_general_ci
+SELECT collation(CAST('A' AS char CHAR SET binary));
+collation(CAST('A' AS char CHAR SET binary))
+binary
 drop table coll_test;

test/mysql_test/test_suite/expr/t/collation_expr.test

@@ -247,6 +247,10 @@ select collation(cast(1 as char));
 SELECT collation(DATE_FORMAT('2009-10-04 22:23:00', '%W %M %Y'));
 select collation(cast('A' as char)), cast('A' as char) < 'a';
 
+#set utf8 binary collation set
+SELECT collation(CAST('A' AS char CHAR SET utf8mb4));
+SELECT collation(CAST('A' AS char CHAR SET binary));
+
 ################################################################
 # tear-down
 drop table coll_test;