diff --git a/mysql-test/main/ansi.result b/mysql-test/main/ansi.result
index 527748e00d53e..810168cc3bd4e 100644
--- a/mysql-test/main/ansi.result
+++ b/mysql-test/main/ansi.result
@@ -46,3 +46,73 @@ t1	CREATE TABLE `t1` (
   PRIMARY KEY (`i`)
 ) ENGINE=MyISAM DEFAULT CHARSET=latin1
 DROP TABLE t1;
+#
+# MDEV-16186 Concatenation operator || returns wrong results in sql_mode=ORACLE
+#
+SET sql_mode=ANSI;
+SELECT -1<<1||1 AS a FROM DUAL;
+a
+18446744073709549568
+SELECT -1||0<<1 AS a FROM DUAL;
+a
+18446744073709551596
+EXPLAIN EXTENDED SELECT -1<<1||1 AS a FROM DUAL;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
+Warnings:
+Note	1003	select -1 << concat(1,1) AS "a"
+EXPLAIN EXTENDED SELECT -1||0<<1 AS a FROM DUAL;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
+Warnings:
+Note	1003	select concat(-1,0) << 1 AS "a"
+SELECT -1+1||1 AS a FROM DUAL;
+a
+10
+SELECT -1||0+1 AS a FROM DUAL;
+a
+-9
+EXPLAIN EXTENDED SELECT -1+1||1 AS a FROM DUAL;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
+Warnings:
+Note	1003	select -1 + concat(1,1) AS "a"
+EXPLAIN EXTENDED SELECT -1||0+1 AS a FROM DUAL;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
+Warnings:
+Note	1003	select concat(-1,0) + 1 AS "a"
+SELECT 1*1||-1 AS a FROM DUAL;
+a
+1
+Warnings:
+Warning	1292	Truncated incorrect DOUBLE value: '1-1'
+SELECT 1||1*-1 AS a FROM DUAL;
+a
+-11
+EXPLAIN EXTENDED SELECT 1*1||-1 AS a FROM DUAL;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
+Warnings:
+Note	1003	select 1 * concat(1,-1) AS "a"
+EXPLAIN EXTENDED SELECT 1||1*-1 AS a FROM DUAL;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
+Warnings:
+Note	1003	select concat(1,1) * -1 AS "a"
+SELECT -1^1||1 AS a FROM DUAL;
+a
+18446744073709551604
+SELECT -1||0^1 AS a FROM DUAL;
+a
+18446744073709551607
+EXPLAIN EXTENDED SELECT -1^1||1 AS a FROM DUAL;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
+Warnings:
+Note	1003	select -1 ^ concat(1,1) AS "a"
+EXPLAIN EXTENDED SELECT -1||0^1 AS a FROM DUAL;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
+Warnings:
+Note	1003	select concat(-1,0) ^ 1 AS "a"
diff --git a/mysql-test/main/ansi.test b/mysql-test/main/ansi.test
index fa7f999954e1a..0620465728bc6 100644
--- a/mysql-test/main/ansi.test
+++ b/mysql-test/main/ansi.test
@@ -39,3 +39,36 @@ SHOW CREATE TABLE t1;
 DROP TABLE t1;
 
 # End of 4.1 tests
+
+
+--echo #
+--echo # MDEV-16186 Concatenation operator || returns wrong results in sql_mode=ORACLE
+--echo #
+
+SET sql_mode=ANSI;
+
+# Concatenation operator || is stronger than numeric dyadic operators ^ * + <<
+
+SELECT -1<<1||1 AS a FROM DUAL;
+SELECT -1||0<<1 AS a FROM DUAL;
+
+EXPLAIN EXTENDED SELECT -1<<1||1 AS a FROM DUAL;
+EXPLAIN EXTENDED SELECT -1||0<<1 AS a FROM DUAL;
+
+SELECT -1+1||1 AS a FROM DUAL;
+SELECT -1||0+1 AS a FROM DUAL;
+
+EXPLAIN EXTENDED SELECT -1+1||1 AS a FROM DUAL;
+EXPLAIN EXTENDED SELECT -1||0+1 AS a FROM DUAL;
+
+SELECT 1*1||-1 AS a FROM DUAL;
+SELECT 1||1*-1 AS a FROM DUAL;
+
+EXPLAIN EXTENDED SELECT 1*1||-1 AS a FROM DUAL;
+EXPLAIN EXTENDED SELECT 1||1*-1 AS a FROM DUAL;
+
+SELECT -1^1||1 AS a FROM DUAL;
+SELECT -1||0^1 AS a FROM DUAL;
+
+EXPLAIN EXTENDED SELECT -1^1||1 AS a FROM DUAL;
+EXPLAIN EXTENDED SELECT -1||0^1 AS a FROM DUAL;
diff --git a/mysql-test/suite/compat/oracle/r/func_concat.result b/mysql-test/suite/compat/oracle/r/func_concat.result
index 230b36b94a5ed..b598f97006ef7 100644
--- a/mysql-test/suite/compat/oracle/r/func_concat.result
+++ b/mysql-test/suite/compat/oracle/r/func_concat.result
@@ -255,3 +255,70 @@ SELECT * FROM v1;
 test
 1
 DROP VIEW v1;
+#
+# MDEV-16186 Concatenation operator || returns wrong results in sql_mode=ORACLE
+#
+SELECT -1<<1||1 AS a FROM DUAL;
+a
+18446744073709549568
+SELECT -1||0<<1 AS a FROM DUAL;
+a
+18446744073709551596
+EXPLAIN EXTENDED SELECT -1<<1||1 AS a FROM DUAL;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
+Warnings:
+Note	1003	select -1 << concat_operator_oracle(1,1) AS "a"
+EXPLAIN EXTENDED SELECT -1||0<<1 AS a FROM DUAL;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
+Warnings:
+Note	1003	select concat_operator_oracle(-1,0) << 1 AS "a"
+SELECT -1+1||1 AS a FROM DUAL;
+a
+01
+SELECT -1||0+1 AS a FROM DUAL;
+a
+-9
+EXPLAIN EXTENDED SELECT -1+1||1 AS a FROM DUAL;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
+Warnings:
+Note	1003	select concat_operator_oracle(-1 + 1,1) AS "a"
+EXPLAIN EXTENDED SELECT -1||0+1 AS a FROM DUAL;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
+Warnings:
+Note	1003	select concat_operator_oracle(-1,0) + 1 AS "a"
+SELECT 1*1||-1 AS a FROM DUAL;
+a
+1-1
+SELECT 1||1*-1 AS a FROM DUAL;
+a
+1-1
+EXPLAIN EXTENDED SELECT 1*1||-1 AS a FROM DUAL;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
+Warnings:
+Note	1003	select concat_operator_oracle(1 * 1,-1) AS "a"
+EXPLAIN EXTENDED SELECT 1||1*-1 AS a FROM DUAL;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
+Warnings:
+Note	1003	select concat_operator_oracle(1,1 * -1) AS "a"
+SELECT -1^1||1 AS a FROM DUAL;
+a
+184467440737095516141
+SELECT -1||0^1 AS a FROM DUAL;
+a
+-11
+EXPLAIN EXTENDED SELECT -1^1||1 AS a FROM DUAL;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
+Warnings:
+Note	1003	select concat_operator_oracle(-1 ^ 1,1) AS "a"
+EXPLAIN EXTENDED SELECT -1||0^1 AS a FROM DUAL;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
+Warnings:
+Note	1003	select concat_operator_oracle(-1,0 ^ 1) AS "a"
diff --git a/mysql-test/suite/compat/oracle/t/func_concat.test b/mysql-test/suite/compat/oracle/t/func_concat.test
index e1d8a5c477fd4..7f9fec4f2fe87 100644
--- a/mysql-test/suite/compat/oracle/t/func_concat.test
+++ b/mysql-test/suite/compat/oracle/t/func_concat.test
@@ -114,3 +114,35 @@ SET sql_mode=ORACLE;
 SHOW CREATE VIEW v1;
 SELECT * FROM v1;
 DROP VIEW v1;
+
+
+--echo #
+--echo # MDEV-16186 Concatenation operator || returns wrong results in sql_mode=ORACLE
+--echo #
+
+# Concatenation operator || has the same precedence with +
+# (stronger than << and weaker than * ^)
+
+SELECT -1<<1||1 AS a FROM DUAL;
+SELECT -1||0<<1 AS a FROM DUAL;
+
+EXPLAIN EXTENDED SELECT -1<<1||1 AS a FROM DUAL;
+EXPLAIN EXTENDED SELECT -1||0<<1 AS a FROM DUAL;
+
+SELECT -1+1||1 AS a FROM DUAL;
+SELECT -1||0+1 AS a FROM DUAL;
+
+EXPLAIN EXTENDED SELECT -1+1||1 AS a FROM DUAL;
+EXPLAIN EXTENDED SELECT -1||0+1 AS a FROM DUAL;
+
+SELECT 1*1||-1 AS a FROM DUAL;
+SELECT 1||1*-1 AS a FROM DUAL;
+
+EXPLAIN EXTENDED SELECT 1*1||-1 AS a FROM DUAL;
+EXPLAIN EXTENDED SELECT 1||1*-1 AS a FROM DUAL;
+
+SELECT -1^1||1 AS a FROM DUAL;
+SELECT -1||0^1 AS a FROM DUAL;
+
+EXPLAIN EXTENDED SELECT -1^1||1 AS a FROM DUAL;
+EXPLAIN EXTENDED SELECT -1||0^1 AS a FROM DUAL;
diff --git a/sql/lex.h b/sql/lex.h
index 7be3e4c9251ea..d336c273a1814 100644
--- a/sql/lex.h
+++ b/sql/lex.h
@@ -722,7 +722,7 @@ static SYMBOL symbols[] = {
   { "YEAR",		SYM(YEAR_SYM)},
   { "YEAR_MONTH",	SYM(YEAR_MONTH_SYM)},
   { "ZEROFILL",		SYM(ZEROFILL)},
-  { "||",		SYM(OR_OR_SYM)}
+  { "||",		SYM(OR2_SYM)}
 };
 
 
diff --git a/sql/sql_lex.cc b/sql/sql_lex.cc
index 95a59c341d556..d132f3a8f2b5e 100644
--- a/sql/sql_lex.cc
+++ b/sql/sql_lex.cc
@@ -839,9 +839,12 @@ int Lex_input_stream::find_keyword(Lex_ident_cli_st *kwd,
     if ((symbol->tok == NOT_SYM) &&
         (m_thd->variables.sql_mode & MODE_HIGH_NOT_PRECEDENCE))
       return NOT2_SYM;
-    if ((symbol->tok == OR_OR_SYM) &&
-        !(m_thd->variables.sql_mode & MODE_PIPES_AS_CONCAT))
-      return OR2_SYM;
+    if ((symbol->tok == OR2_SYM) &&
+        (m_thd->variables.sql_mode & MODE_PIPES_AS_CONCAT))
+    {
+      return (m_thd->variables.sql_mode & MODE_ORACLE) ?
+             ORACLE_CONCAT_SYM : MYSQL_CONCAT_SYM;
+    }
 
     return symbol->tok;
   }
diff --git a/sql/sql_yacc.yy b/sql/sql_yacc.yy
index e4f005a048801..765cc4d41ea80 100644
--- a/sql/sql_yacc.yy
+++ b/sql/sql_yacc.yy
@@ -892,10 +892,10 @@ bool my_yyoverflow(short **a, YYSTYPE **b, size_t *yystacksize);
 %parse-param { THD *thd }
 %lex-param { THD *thd }
 /*
-  Currently there are 127 shift/reduce conflicts.
+  Currently there are 122 shift/reduce conflicts.
   We should not introduce new conflicts any more.
 */
-%expect 127
+%expect 122
 
 /*
    Comments for TOKENS.
@@ -1073,6 +1073,7 @@ bool my_yyoverflow(short **a, YYSTYPE **b, size_t *yystacksize);
 %token  MIN_SYM                       /* SQL-2003-N */
 %token  MODIFIES_SYM                  /* SQL-2003-R */
 %token  MOD_SYM                       /* SQL-2003-N */
+%token  MYSQL_CONCAT_SYM              /* OPERATOR */
 %token  NATURAL                       /* SQL-2003-R */
 %token  NCHAR_STRING
 %token  NE                            /* OPERATOR */
@@ -1089,9 +1090,9 @@ bool my_yyoverflow(short **a, YYSTYPE **b, size_t *yystacksize);
 %token  ON                            /* SQL-2003-R */
 %token  OPTIMIZE
 %token  OPTIONALLY
+%token  ORACLE_CONCAT_SYM             /* INTERNAL */
 %token  OR2_SYM
 %token  ORDER_SYM                     /* SQL-2003-R */
-%token  OR_OR_SYM                     /* OPERATOR */
 %token  OR_SYM                        /* SQL-2003-R */
 %token  OUTER
 %token  OUTFILE
@@ -1654,7 +1655,7 @@ bool my_yyoverflow(short **a, YYSTYPE **b, size_t *yystacksize);
 /* A dummy token to force the priority of table_ref production in a join. */
 %left   TABLE_REF_PRIORITY
 %left   SET_VAR
-%left   OR_OR_SYM OR_SYM OR2_SYM
+%left   OR_SYM OR2_SYM
 %left   XOR
 %left   AND_SYM AND_AND_SYM
 %left   BETWEEN_SYM CASE_SYM WHEN_SYM THEN_SYM ELSE
@@ -1662,9 +1663,10 @@ bool my_yyoverflow(short **a, YYSTYPE **b, size_t *yystacksize);
 %left   '|'
 %left   '&'
 %left   SHIFT_LEFT SHIFT_RIGHT
-%left   '-' '+'
+%left   '-' '+' ORACLE_CONCAT_SYM
 %left   '*' '/' '%' DIV_SYM MOD_SYM
 %left   '^'
+%left   MYSQL_CONCAT_SYM
 %left   NEG '~'
 %right  NOT_SYM NOT2_SYM
 %right  BINARY COLLATE_SYM
@@ -1803,6 +1805,7 @@ bool my_yyoverflow(short **a, YYSTYPE **b, size_t *yystacksize);
         variable variable_aux bool_pri
         predicate bit_expr parenthesized_expr
         table_wild simple_expr column_default_non_parenthesized_expr udf_expr
+        primary_expr string_factor_expr mysql_concatenation_expr
         select_sublist_qualified_asterisk
         expr_or_default set_expr_or_default
         geometry_function signed_literal expr_or_literal
@@ -2056,8 +2059,9 @@ END_OF_INPUT
 
 %type <NONE>
         '-' '+' '*' '/' '%' '(' ')'
-        ',' '!' '{' '}' '&' '|' AND_SYM OR_SYM OR_OR_SYM BETWEEN_SYM CASE_SYM
+        ',' '!' '{' '}' '&' '|' AND_SYM OR_SYM BETWEEN_SYM CASE_SYM
         THEN_SYM WHEN_SYM DIV_SYM MOD_SYM OR2_SYM AND_AND_SYM DELETE_SYM
+        MYSQL_CONCAT_SYM ORACLE_CONCAT_SYM
 
 %type <with_clause> opt_with_clause with_clause
 
@@ -9697,14 +9701,14 @@ predicate:
             if (unlikely($$ == NULL))
               MYSQL_YYABORT;
           }
-        | bit_expr LIKE simple_expr opt_escape
+        | bit_expr LIKE mysql_concatenation_expr opt_escape
           {
             $$= new (thd->mem_root) Item_func_like(thd, $1, $3, $4,
                                                    Lex->escape_used);
             if (unlikely($$ == NULL))
               MYSQL_YYABORT;
           }
-        | bit_expr not LIKE simple_expr opt_escape
+        | bit_expr not LIKE mysql_concatenation_expr opt_escape
           {
             Item *item= new (thd->mem_root) Item_func_like(thd, $1, $4, $5,
                                                              Lex->escape_used);
@@ -9755,6 +9759,13 @@ bit_expr:
             if (unlikely($$ == NULL))
               MYSQL_YYABORT;
           }
+        | bit_expr ORACLE_CONCAT_SYM bit_expr
+          {
+            $$= new (thd->mem_root) Item_func_concat_operator_oracle(thd,
+                                                                     $1, $3);
+            if (unlikely($$ == NULL))
+              MYSQL_YYABORT;
+          }
         | bit_expr '+' bit_expr %prec '+'
           {
             $$= new (thd->mem_root) Item_func_plus(thd, $1, $3);
@@ -9834,7 +9845,7 @@ bit_expr:
             if (unlikely($$ == NULL))
               MYSQL_YYABORT;
           }
-        | simple_expr
+        | mysql_concatenation_expr %prec '^'
         ;
 
 or:
@@ -10113,26 +10124,28 @@ column_default_non_parenthesized_expr:
           }
         ;
 
-simple_expr:
+primary_expr:
           column_default_non_parenthesized_expr
-        | simple_expr COLLATE_SYM collation_name %prec NEG
+        | '(' parenthesized_expr ')' { $$= $2; }
+        ;
+
+string_factor_expr:
+          primary_expr
+        | string_factor_expr COLLATE_SYM collation_name
           {
             if (unlikely(!($$= new (thd->mem_root) Item_func_set_collation(thd, $1, $3))))
               MYSQL_YYABORT;
           }
-        | '(' parenthesized_expr ')' { $$= $2; }
-        | BINARY simple_expr %prec NEG
+        ;
+
+simple_expr:
+          string_factor_expr %prec NEG
+        | BINARY simple_expr
           {
             Type_cast_attributes at(&my_charset_bin);
             if (unlikely(!($$= type_handler_long_blob.create_typecast_item(thd, $2, at))))
               MYSQL_YYABORT;
           }
-        | simple_expr OR_OR_SYM simple_expr
-          {
-            $$= new (thd->mem_root) Item_func_concat(thd, $1, $3);
-            if (unlikely($$ == NULL))
-              MYSQL_YYABORT;
-          }
         | '+' simple_expr %prec NEG
           {
             $$= $2;
@@ -10157,6 +10170,16 @@ simple_expr:
           }
         ;
 
+mysql_concatenation_expr:
+          simple_expr
+        | mysql_concatenation_expr MYSQL_CONCAT_SYM simple_expr
+          {
+            $$= new (thd->mem_root) Item_func_concat(thd, $1, $3);
+            if (unlikely($$ == NULL))
+              MYSQL_YYABORT;
+          }
+        ;
+
 function_call_keyword_timestamp:
           TIMESTAMP '(' expr ')'
           {
diff --git a/sql/sql_yacc_ora.yy b/sql/sql_yacc_ora.yy
index cb1d7481efb63..736837b9ca1c8 100644
--- a/sql/sql_yacc_ora.yy
+++ b/sql/sql_yacc_ora.yy
@@ -278,10 +278,10 @@ bool my_yyoverflow(short **a, YYSTYPE **b, size_t *yystacksize);
 %parse-param { THD *thd }
 %lex-param { THD *thd }
 /*
-  Currently there are 104 shift/reduce conflicts.
+  Currently there are 99 shift/reduce conflicts.
   We should not introduce new conflicts any more.
 */
-%expect 104
+%expect 99
 
 /*
    Comments for TOKENS.
@@ -459,6 +459,7 @@ bool my_yyoverflow(short **a, YYSTYPE **b, size_t *yystacksize);
 %token  MIN_SYM                       /* SQL-2003-N */
 %token  MODIFIES_SYM                  /* SQL-2003-R */
 %token  MOD_SYM                       /* SQL-2003-N */
+%token  MYSQL_CONCAT_SYM              /* OPERATOR */
 %token  NATURAL                       /* SQL-2003-R */
 %token  NCHAR_STRING
 %token  NE                            /* OPERATOR */
@@ -475,9 +476,9 @@ bool my_yyoverflow(short **a, YYSTYPE **b, size_t *yystacksize);
 %token  ON                            /* SQL-2003-R */
 %token  OPTIMIZE
 %token  OPTIONALLY
+%token  ORACLE_CONCAT_SYM             /* INTERNAL */
 %token  OR2_SYM
 %token  ORDER_SYM                     /* SQL-2003-R */
-%token  OR_OR_SYM                     /* OPERATOR */
 %token  OR_SYM                        /* SQL-2003-R */
 %token  OUTER
 %token  OUTFILE
@@ -1040,7 +1041,7 @@ bool my_yyoverflow(short **a, YYSTYPE **b, size_t *yystacksize);
 /* A dummy token to force the priority of table_ref production in a join. */
 %left   TABLE_REF_PRIORITY
 %left   SET_VAR
-%left   OR_OR_SYM OR_SYM OR2_SYM
+%left   OR_SYM OR2_SYM
 %left   XOR
 %left   AND_SYM AND_AND_SYM
 %left   BETWEEN_SYM CASE_SYM WHEN_SYM THEN_SYM ELSE
@@ -1048,9 +1049,10 @@ bool my_yyoverflow(short **a, YYSTYPE **b, size_t *yystacksize);
 %left   '|'
 %left   '&'
 %left   SHIFT_LEFT SHIFT_RIGHT
-%left   '-' '+'
+%left   '-' '+' ORACLE_CONCAT_SYM
 %left   '*' '/' DIV_SYM MOD_SYM
 %left   '^'
+%left   MYSQL_CONCAT_SYM
 %left   NEG '~'
 %right  NOT_SYM NOT2_SYM
 %right  BINARY COLLATE_SYM
@@ -1196,6 +1198,7 @@ bool my_yyoverflow(short **a, YYSTYPE **b, size_t *yystacksize);
         variable variable_aux bool_pri
         predicate bit_expr parenthesized_expr
         table_wild simple_expr column_default_non_parenthesized_expr udf_expr
+        primary_expr string_factor_expr mysql_concatenation_expr
         select_sublist_qualified_asterisk
         expr_or_default set_expr_or_default
         geometry_function signed_literal expr_or_literal
@@ -1469,8 +1472,9 @@ END_OF_INPUT
 
 %type <NONE>
         '-' '+' '*' '/' '%' '(' ')'
-        ',' '!' '{' '}' '&' '|' AND_SYM OR_SYM OR_OR_SYM BETWEEN_SYM CASE_SYM
+        ',' '!' '{' '}' '&' '|' AND_SYM OR_SYM BETWEEN_SYM CASE_SYM
         THEN_SYM WHEN_SYM DIV_SYM MOD_SYM OR2_SYM AND_AND_SYM DELETE_SYM
+        MYSQL_CONCAT_SYM ORACLE_CONCAT_SYM
 
 %type <with_clause> opt_with_clause with_clause
 
@@ -9443,14 +9447,14 @@ predicate:
             if (unlikely($$ == NULL))
               MYSQL_YYABORT;
           }
-        | bit_expr LIKE simple_expr opt_escape
+        | bit_expr LIKE mysql_concatenation_expr opt_escape
           {
             $$= new (thd->mem_root) Item_func_like(thd, $1, $3, $4,
                                                    Lex->escape_used);
             if (unlikely($$ == NULL))
               MYSQL_YYABORT;
           }
-        | bit_expr not LIKE simple_expr opt_escape
+        | bit_expr not LIKE mysql_concatenation_expr opt_escape
           {
             Item *item= new (thd->mem_root) Item_func_like(thd, $1, $4, $5,
                                                              Lex->escape_used);
@@ -9501,6 +9505,13 @@ bit_expr:
             if (unlikely($$ == NULL))
               MYSQL_YYABORT;
           }
+        | bit_expr ORACLE_CONCAT_SYM bit_expr
+          {
+            $$= new (thd->mem_root) Item_func_concat_operator_oracle(thd,
+                                                                     $1, $3);
+            if (unlikely($$ == NULL))
+              MYSQL_YYABORT;
+          }
         | bit_expr '+' bit_expr %prec '+'
           {
             $$= new (thd->mem_root) Item_func_plus(thd, $1, $3);
@@ -9574,7 +9585,7 @@ bit_expr:
             if (unlikely($$ == NULL))
               MYSQL_YYABORT;
           }
-        | simple_expr
+        | mysql_concatenation_expr %prec '^'
         ;
 
 or:
@@ -9909,28 +9920,29 @@ column_default_non_parenthesized_expr:
           }
         ;
 
-simple_expr:
+primary_expr:
           column_default_non_parenthesized_expr
         | explicit_cursor_attr
-        | simple_expr COLLATE_SYM collation_name %prec NEG
+        | '(' parenthesized_expr ')' { $$= $2; }
+        ;
+
+string_factor_expr:
+          primary_expr
+        | string_factor_expr COLLATE_SYM collation_name
           {
             if (unlikely(!($$= new (thd->mem_root) Item_func_set_collation(thd, $1, $3))))
               MYSQL_YYABORT;
           }
-        | '(' parenthesized_expr ')' { $$= $2; }
-        | BINARY simple_expr %prec NEG
+        ;
+
+simple_expr:
+          string_factor_expr %prec NEG
+        | BINARY simple_expr
           {
             Type_cast_attributes at(&my_charset_bin);
             if (unlikely(!($$= type_handler_long_blob.create_typecast_item(thd, $2, at))))
               MYSQL_YYABORT;
           }
-        | simple_expr OR_OR_SYM simple_expr
-          {
-            $$= new (thd->mem_root) Item_func_concat_operator_oracle(thd,
-                                                                     $1, $3);
-            if (unlikely($$ == NULL))
-              MYSQL_YYABORT;
-          }
         | '+' simple_expr %prec NEG
           {
             $$= $2;
@@ -9955,6 +9967,17 @@ simple_expr:
           }
         ;
 
+mysql_concatenation_expr:
+          simple_expr
+        | mysql_concatenation_expr MYSQL_CONCAT_SYM simple_expr
+          {
+            $$= new (thd->mem_root) Item_func_concat(thd, $1, $3);
+            if (unlikely($$ == NULL))
+              MYSQL_YYABORT;
+          }
+        ;
+
+
 /*
   Function call syntax using official SQL 2003 keywords.
   Because the function name is an official token,