MDEV-16630: Ambiguous error message when check constraint matches table name

One can create table with the same name for `field` and `table` `check` constraint.
For example:
`create table t(a int check(a>0), constraint a check(a>10));`
But when inserting new rows same error is always raised.
For example with
```insert into t values (-1);```
and
```insert into t values (10);```
same error `ER_CONSTRAINT_FAILED` is obtained and it is not clear which constraint is violated.
This patch solve this error so that in case if field constraint is violated the first parameter
in the error message is `table.field_name` and if table constraint is violated the first parameter
in error message is `constraint_name`.

5 files changed, 72 insertions, 9 deletions

diff --git a/mysql-test/r/check_constraint.result b/mysql-test/r/check_constraint.result
index 9a32e6f12bc..9a228f9ccc7 100644
--- a/mysql-test/r/check_constraint.result
+++ b/mysql-test/r/check_constraint.result
@@ -10,9 +10,9 @@ t1	CREATE TABLE `t1` (
 ) ENGINE=MyISAM DEFAULT CHARSET=latin1
 insert into t1 values (100,100);
 insert into t1 values (1,1);
-ERROR 23000: CONSTRAINT `a` failed for `test`.`t1`
+ERROR 23000: CONSTRAINT `t1.a` failed for `test`.`t1`
 insert into t1 values (20,1);
-ERROR 23000: CONSTRAINT `b` failed for `test`.`t1`
+ERROR 23000: CONSTRAINT `t1.b` failed for `test`.`t1`
 insert into t1 values (20,30);
 ERROR 23000: CONSTRAINT `min` failed for `test`.`t1`
 insert into t1 values (500,500);
@@ -60,7 +60,7 @@ t1	CREATE TABLE `t1` (
   CONSTRAINT `CONSTRAINT_1` CHECK (`a` + `b` + `c` < 500)
 ) ENGINE=MyISAM DEFAULT CHARSET=latin1
 insert into t1 values(105,105,105);
-ERROR 23000: CONSTRAINT `c` failed for `test`.`t1`
+ERROR 23000: CONSTRAINT `t1.c` failed for `test`.`t1`
 insert into t1 values(249,249,9);
 ERROR 23000: CONSTRAINT `CONSTRAINT_1` failed for `test`.`t1`
 insert into t1 values(105,105,9);
@@ -145,7 +145,7 @@ ERROR HY000: Function or expression '@b' cannot be used in the CHECK clause of `
 create table t1 (a int check (a = 1));
 insert t1 values (1);
 insert t1 values (2);
-ERROR 23000: CONSTRAINT `a` failed for `test`.`t1`
+ERROR 23000: CONSTRAINT `t1.a` failed for `test`.`t1`
 insert t1 values (NULL);
 select * from t1;
 a
@@ -165,13 +165,13 @@ ERROR 22007: Truncated incorrect DOUBLE value: 'Ken'
 SHOW WARNINGS;
 Level	Code	Message
 Error	1292	Truncated incorrect DOUBLE value: 'Ken'
-Error	4025	CONSTRAINT `FirstName` failed for `test`.`t1`
+Error	4025	CONSTRAINT `t1.FirstName` failed for `test`.`t1`
 INSERT INTO t1 VALUES (NULL, 'Ken'),(NULL, 'Brian');
 ERROR 22007: Truncated incorrect DOUBLE value: 'Ken'
 SHOW WARNINGS;
 Level	Code	Message
 Error	1292	Truncated incorrect DOUBLE value: 'Ken'
-Error	4025	CONSTRAINT `FirstName` failed for `test`.`t1`
+Error	4025	CONSTRAINT `t1.FirstName` failed for `test`.`t1`
 INSERT IGNORE INTO t1 VALUES (NULL, 'Ken');
 Warnings:
 Warning	1292	Truncated incorrect DOUBLE value: 'Ken'
@@ -197,3 +197,28 @@ EmployeeID	FirstName
 5	Ken
 6	Brian
 drop table t1;
+#
+# MDEV-16630: Ambiguous error message when check constraint
+#             matches table name
+#
+use test;
+drop table if exists t;
+create table t(a int, b int check(b>0),
+constraint b check(a<b), constraint a check(a>0),
+constraint x check (a>10));
+show create table t;
+Table	Create Table
+t	CREATE TABLE `t` (
+  `a` int(11) DEFAULT NULL,
+  `b` int(11) DEFAULT NULL CHECK (`b` > 0),
+  CONSTRAINT `b` CHECK (`a` < `b`),
+  CONSTRAINT `a` CHECK (`a` > 0),
+  CONSTRAINT `x` CHECK (`a` > 10)
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+# Field constraint 'b' will fail
+insert into t values (-1, 0);
+ERROR 23000: CONSTRAINT `t.b` failed for `test`.`t`
+# Table constraint 'b' will fail
+insert into t values (1,1);
+ERROR 23000: CONSTRAINT `b` failed for `test`.`t`
+drop table t;
diff --git a/mysql-test/r/constraints.result b/mysql-test/r/constraints.result
index fe9398ea8ce..57cfbfb3d37 100644
--- a/mysql-test/r/constraints.result
+++ b/mysql-test/r/constraints.result
@@ -7,7 +7,7 @@ t1	CREATE TABLE `t1` (
 ) ENGINE=MyISAM DEFAULT CHARSET=latin1
 insert into t1 values (1);
 insert into t1 values (0);
-ERROR 23000: CONSTRAINT `a` failed for `test`.`t1`
+ERROR 23000: CONSTRAINT `t1.a` failed for `test`.`t1`
 drop table t1;
 create table t1 (a int, b int, check (a>b));
 show create table t1;
diff --git a/mysql-test/r/type_json.result b/mysql-test/r/type_json.result
index 2c1fdbe2b95..0045847097b 100644
--- a/mysql-test/r/type_json.result
+++ b/mysql-test/r/type_json.result
@@ -20,7 +20,7 @@ t1	CREATE TABLE `t1` (
 ) ENGINE=MyISAM DEFAULT CHARSET=latin1
 insert t1 values ('[]');
 insert t1 values ('a');
-ERROR 23000: CONSTRAINT `a` failed for `test`.`t1`
+ERROR 23000: CONSTRAINT `t1.a` failed for `test`.`t1`
 set timestamp=unix_timestamp('2010:11:12 13:14:15');
 create or replace table t1(a json default(json_object('now', now())));
 show create table t1;
diff --git a/mysql-test/t/check_constraint.test b/mysql-test/t/check_constraint.test
index 02081071bd4..be06c3ec579 100644
--- a/mysql-test/t/check_constraint.test
+++ b/mysql-test/t/check_constraint.test
@@ -135,3 +135,31 @@ INSERT INTO t1 VALUES (NULL, 'Ken'),(NULL, 'Brian');
 set sql_mode=default;
 select * from t1;
 drop table t1;
+
+--echo #
+--echo # MDEV-16630: Ambiguous error message when check constraint
+--echo #             matches table name
+--echo #
+
+use test;
+--disable_warnings
+drop table if exists t;
+--enable_warnings
+
+create table t(a int, b int check(b>0),
+               constraint b check(a<b), constraint a check(a>0),
+               constraint x check (a>10));
+
+show create table t;
+
+# Generate error when field constraint 'b' is violated
+--echo # Field constraint 'b' will fail
+--error ER_CONSTRAINT_FAILED
+insert into t values (-1, 0);
+
+# Generate error when table constraint 'b' is violated.
+--echo # Table constraint 'b' will fail
+--error ER_CONSTRAINT_FAILED
+insert into t values (1,1);
+
+drop table t;
diff --git a/sql/table.cc b/sql/table.cc
index 917d194047c..7cb84bcc5ea 100644
--- a/sql/table.cc
+++ b/sql/table.cc
@@ -5142,8 +5142,18 @@ int TABLE::verify_constraints(bool ignore_failure)
       if (((*chk)->expr->val_int() == 0 && !(*chk)->expr->null_value) ||
           in_use->is_error())
       {
+        StringBuffer<MAX_FIELD_WIDTH> field_error(system_charset_info);
+        enum_vcol_info_type vcol_type= (*chk)->get_vcol_type();
+        DBUG_ASSERT(vcol_type == VCOL_CHECK_TABLE ||
+                    vcol_type == VCOL_CHECK_FIELD);
+        if (vcol_type == VCOL_CHECK_FIELD)
+        {
+          field_error.append(s->table_name.str);
+          field_error.append(".");
+        }
+        field_error.append((*chk)->name.str);
         my_error(ER_CONSTRAINT_FAILED,
-                 MYF(ignore_failure ? ME_JUST_WARNING : 0), (*chk)->name.str,
+                 MYF(ignore_failure ? ME_JUST_WARNING : 0), field_error.c_ptr(),
                  s->db.str, s->table_name.str);
         return ignore_failure ? VIEW_CHECK_SKIP : VIEW_CHECK_ERROR;
       }