ddl, table: fix Duplicate partition field in list partition

ddl/db_partition_test.go

@@ -901,6 +901,14 @@ func (s *testIntegrationSuite1) TestCreateTableWithListColumnsPartition(c *C) {
 			"create table t (a bigint, b int) partition by list columns (a,b) (partition p0 values in ((1,1),(2,2)), partition p1 values in ((+1,1)));",
 			ddl.ErrMultipleDefConstInListPart,
 		},
+		{
+			"create table t1 (a int, b int) partition by list columns(a,a) ( partition p values in ((1,1)));",
+			ddl.ErrSameNamePartitionField,
+		},
+		{
+			"create table t1 (a int, b int) partition by list columns(a,b,b) ( partition p values in ((1,1,1)));",
+			ddl.ErrSameNamePartitionField,
+		},
 		{
 			`create table t1 (id int key, name varchar(10), unique index idx(name)) partition by list columns (id) (
 				    partition p0 values in (3,5,6,9,17),

ddl/ddl_api.go

@@ -1744,6 +1744,9 @@ func checkPartitionDefinitionConstraints(ctx sessionctx.Context, tbInfo *model.T
 	if err = checkAddPartitionOnTemporaryMode(tbInfo); err != nil {
 		return err
 	}
+	if err = checkPartitionColumnsUnique(tbInfo); err != nil {
+		return err
+	}
 
 	switch tbInfo.Partition.Type {
 	case model.PartitionTypeRange:

ddl/error.go

@@ -177,6 +177,8 @@ var (
 	ErrDropPartitionNonExistent = dbterror.ClassDDL.NewStd(mysql.ErrDropPartitionNonExistent)
 	// ErrSameNamePartition returns duplicate partition name.
 	ErrSameNamePartition = dbterror.ClassDDL.NewStd(mysql.ErrSameNamePartition)
+	// ErrSameNamePartitionField returns duplicate partition field.
+	ErrSameNamePartitionField = dbterror.ClassDDL.NewStd(mysql.ErrSameNamePartitionField)
 	// ErrRangeNotIncreasing returns values less than value must be strictly increasing for each partition.
 	ErrRangeNotIncreasing = dbterror.ClassDDL.NewStd(mysql.ErrRangeNotIncreasing)
 	// ErrPartitionMaxvalue returns maxvalue can only be used in last partition definition.

ddl/partition.go

@@ -1679,6 +1679,20 @@ func checkAddPartitionOnTemporaryMode(tbInfo *model.TableInfo) error {
 	return nil
 }
 
+func checkPartitionColumnsUnique(tbInfo *model.TableInfo) error {
+	if len(tbInfo.Partition.Columns) <= 1 {
+		return nil
+	}
+	var columnsMap = make(map[string]struct{})
+	for _, col := range tbInfo.Partition.Columns {
+		if _, ok := columnsMap[col.L]; ok {
+			return ErrSameNamePartitionField.GenWithStackByArgs(col.L)
+		}
+		columnsMap[col.L] = struct{}{}
+	}
+	return nil
+}
+
 func checkNoHashPartitions(ctx sessionctx.Context, partitionNum uint64) error {
 	if partitionNum == 0 {
 		return ast.ErrNoParts.GenWithStackByArgs("partitions")

errors.toml

@@ -506,6 +506,11 @@ error = '''
 This partition function is not allowed
 '''
 
+["ddl:1652"]
+error = '''
+Duplicate partition field name '%-.192s'
+'''
+
 ["ddl:1654"]
 error = '''
 Partition column values of incorrect type