This is an automated cherry-pick of pingcap#47267

Signed-off-by: ti-chi-bot <ti-community-prow-bot@tidb.io>

expression/builtin_cast.go

@@ -1277,7 +1277,11 @@ func (b *builtinCastStringAsDecimalSig) evalDecimal(row chunk.Row) (res *types.M
 	res = new(types.MyDecimal)
 	sc := b.ctx.GetSessionVars().StmtCtx
 	if !(b.inUnion && mysql.HasUnsignedFlag(b.tp.GetFlag()) && isNegative) {
-		err = sc.HandleTruncate(res.FromString([]byte(val)))
+		err = res.FromString([]byte(val))
+		if err == types.ErrTruncated {
+			err = types.ErrTruncatedWrongVal.GenWithStackByArgs("DECIMAL", []byte(val))
+		}
+		err = sc.HandleTruncate(err)
 		if err != nil {
 			return res, false, err
 		}

tests/integrationtest/r/expression/cast.result

@@ -0,0 +1,90 @@
+select cast('' as signed);
+cast('' as signed)
+0
+Level	Code	Message
+Warning	1292	Truncated incorrect INTEGER value: ''
+select cast('12345abcde' as signed);
+cast('12345abcde' as signed)
+12345
+Level	Code	Message
+Warning	1292	Truncated incorrect INTEGER value: '12345abcde'
+select cast('123e456' as signed);
+cast('123e456' as signed)
+123
+Level	Code	Message
+Warning	1292	Truncated incorrect INTEGER value: '123e456'
+select cast('-12345abcde' as signed);
+cast('-12345abcde' as signed)
+-12345
+Level	Code	Message
+Warning	1292	Truncated incorrect INTEGER value: '-12345abcde'
+select cast('-123e456' as signed);
+cast('-123e456' as signed)
+-123
+Level	Code	Message
+Warning	1292	Truncated incorrect INTEGER value: '-123e456'
+select coercibility(binary('a'));
+coercibility(binary('a'))
+2
+select coercibility(cast('a' as char(10)));
+coercibility(cast('a' as char(10)))
+2
+select coercibility(convert('abc', char(10)));
+coercibility(convert('abc', char(10)))
+2
+drop table if exists t;
+create table t(d1 double, f float, d2 decimal(24,8));
+insert into t values(0, 0, 0);
+select cast(111.1 as datetime) from t;
+cast(111.1 as datetime)
+2000-01-11 00:00:00
+select cast(1311.1 as datetime) from t;
+cast(1311.1 as datetime)
+NULL
+insert into t values(111.1, 1122.1, 31212.111);
+insert into t values(121212.1111, 1121212.111111, 11121212.111111);
+insert into t values(99991111.1111111, 101.1111111, 20121212121212.1111111);
+insert into t values(NULL, NULL, NULL);
+insert into t values(1.1, 48.1, 100.1);
+insert into t values(1301.11, 1131.111, 100001111.111);
+insert into t values(20121212121260.1111111, 20121212126012.1111111, 20121212241212.1111111);
+select cast(d1 as datetime), cast(f as datetime), cast(d2 as datetime) from t;
+cast(d1 as datetime)	cast(f as datetime)	cast(d2 as datetime)
+NULL	NULL	NULL
+NULL	NULL	NULL
+NULL	NULL	NULL
+NULL	NULL	NULL
+0000-00-00 00:00:00	0000-00-00 00:00:00	0000-00-00 00:00:00
+2000-01-11 00:00:00	2000-11-22 00:00:00	2003-12-12 00:00:00
+2012-12-12 00:00:00	0112-12-12 00:00:00	1112-12-12 00:00:00
+9999-11-11 00:00:00	2000-01-01 00:00:00	2012-12-12 12:12:12
+drop table if exists t;
+create table t (col1 bigint, col2 double, col3 decimal, col4 varchar(20), col5 json);
+insert into t values (1, 1, 1, "1", "1");
+insert into t values (null, null, null, null, null);
+select cast(col1 as time), cast(col2 as time), cast(col3 as time), cast(col4 as time), cast(col5 as time) from t where col1 = 1;
+cast(col1 as time)	cast(col2 as time)	cast(col3 as time)	cast(col4 as time)	cast(col5 as time)
+00:00:01	00:00:01	00:00:01	00:00:01	NULL
+select cast(col1 as time), cast(col2 as time), cast(col3 as time), cast(col4 as time), cast(col5 as time) from t where col1 is null;
+cast(col1 as time)	cast(col2 as time)	cast(col3 as time)	cast(col4 as time)	cast(col5 as time)
+NULL	NULL	NULL	NULL	NULL
+select cast(col1 as time(31)) from t where col1 is null;
+Error 1426 (42000): Too big precision 31 specified for column 'CAST'. Maximum is 6.
+select cast(col2 as time(31)) from t where col1 is null;
+Error 1426 (42000): Too big precision 31 specified for column 'CAST'. Maximum is 6.
+select cast(col3 as time(31)) from t where col1 is null;
+Error 1426 (42000): Too big precision 31 specified for column 'CAST'. Maximum is 6.
+select cast(col4 as time(31)) from t where col1 is null;
+Error 1426 (42000): Too big precision 31 specified for column 'CAST'. Maximum is 6.
+select cast(col5 as time(31)) from t where col1 is null;
+Error 1426 (42000): Too big precision 31 specified for column 'CAST'. Maximum is 6.
+drop table if exists t1;
+create table t1 (c1 text);
+insert into t1 values ('a');
+update t1 set c1 = cast('61qw' as decimal);
+Error 1292 (22007): Truncated incorrect DECIMAL value: '61qw'
+select cast('61qw' as decimal);
+cast('61qw' as decimal)
+61
+Level	Code	Message
+Warning	1292	Truncated incorrect DECIMAL value: '61qw'

tests/integrationtest/t/expression/cast.test

@@ -0,0 +1,57 @@
+# TestCastStrToInt
+--enable_warnings
+select cast('' as signed);
+select cast('12345abcde' as signed);
+select cast('123e456' as signed);
+select cast('-12345abcde' as signed);
+select cast('-123e456' as signed);
+--disable_warnings
+
+# TestCastCoer
+select coercibility(binary('a'));
+select coercibility(cast('a' as char(10)));
+select coercibility(convert('abc', char(10)));
+
+# TestCastRealAsTime
+drop table if exists t;
+create table t(d1 double, f float, d2 decimal(24,8));
+insert into t values(0, 0, 0);
+select cast(111.1 as datetime) from t;
+select cast(1311.1 as datetime) from t;
+insert into t values(111.1, 1122.1, 31212.111);
+insert into t values(121212.1111, 1121212.111111, 11121212.111111);
+insert into t values(99991111.1111111, 101.1111111, 20121212121212.1111111);
+insert into t values(NULL, NULL, NULL);
+insert into t values(1.1, 48.1, 100.1);
+insert into t values(1301.11, 1131.111, 100001111.111);
+insert into t values(20121212121260.1111111, 20121212126012.1111111, 20121212241212.1111111);
+-- sorted_result
+select cast(d1 as datetime), cast(f as datetime), cast(d2 as datetime) from t;
+
+# TestCastAsTime
+drop table if exists t;
+create table t (col1 bigint, col2 double, col3 decimal, col4 varchar(20), col5 json);
+insert into t values (1, 1, 1, "1", "1");
+insert into t values (null, null, null, null, null);
+select cast(col1 as time), cast(col2 as time), cast(col3 as time), cast(col4 as time), cast(col5 as time) from t where col1 = 1;
+select cast(col1 as time), cast(col2 as time), cast(col3 as time), cast(col4 as time), cast(col5 as time) from t where col1 is null;
+-- error 1426
+select cast(col1 as time(31)) from t where col1 is null;
+-- error 1426
+select cast(col2 as time(31)) from t where col1 is null;
+-- error 1426
+select cast(col3 as time(31)) from t where col1 is null;
+-- error 1426
+select cast(col4 as time(31)) from t where col1 is null;
+-- error 1426
+select cast(col5 as time(31)) from t where col1 is null;
+
+# TestCastErrMsg
+drop table if exists t1;
+create table t1 (c1 text);
+insert into t1 values ('a');
+--error 1292
+update t1 set c1 = cast('61qw' as decimal);
+--enable_warnings
+select cast('61qw' as decimal);
+--disable_warnings