ddl: fix change partition key type to a not allowed type

ddl/db_partition_test.go

@@ -4539,6 +4539,7 @@ func TestAlterModifyColumnOnPartitionedTable(t *testing.T) {
 	store := testkit.CreateMockStore(t)
 	tk := testkit.NewTestKit(t, store)
 	tk.MustExec("create database AlterPartTable")
+	defer tk.MustExec("drop database AlterPartTable")
 	tk.MustExec("use AlterPartTable")
 	tk.MustExec(`create table t (a int unsigned PRIMARY KEY, b varchar(255), key (b))`)
 	tk.MustExec(`insert into t values (7, "07"), (8, "08"),(23,"23"),(34,"34💥"),(46,"46"),(57,"57")`)
@@ -4662,4 +4663,23 @@ func TestAlterModifyColumnOnPartitionedTable(t *testing.T) {
 		"34 34💥",
 		"46 46",
 		"57 57"))
+	tk.MustExec("create table t1 (a tinyint, b char) partition by range (a) ( partition p0 values less than (10) )")
+	err := tk.ExecToErr("alter table t1 modify a char")
+	require.Error(t, err)
+	require.Equal(t, "[ddl:1659]Field 'a' is of a not allowed type for this type of partitioning", err.Error())
+
+	tk.MustExec("create table t2 (a tinyint, b char) partition by range (a-1) ( partition p0 values less than (10) )")
+	err = tk.ExecToErr("alter table t2 modify a char")
+	require.Error(t, err)
+	require.Equal(t, "[ddl:1491]The PARTITION function returns the wrong type", err.Error())
+
+	tk.MustExec("create table t3 (a tinyint, b char) partition by hash(a) partitions 4;")
+	err = tk.ExecToErr("alter table t3 modify a char")
+	require.Error(t, err)
+	require.Equal(t, "[ddl:1659]Field 'a' is of a not allowed type for this type of partitioning", err.Error())
+
+	tk.MustExec("create table t4 (a tinyint, b char) partition by hash(a-1) partitions 4;")
+	err = tk.ExecToErr("alter table t4 modify a char")
+	require.Error(t, err)
+	require.Equal(t, "[ddl:1491]The PARTITION function returns the wrong type", err.Error())
 }

ddl/ddl_api.go

@@ -38,6 +38,7 @@ import (
 	"github.com/pingcap/tidb/infoschema"
 	"github.com/pingcap/tidb/kv"
 	"github.com/pingcap/tidb/meta/autoid"
+	"github.com/pingcap/tidb/parser"
 	"github.com/pingcap/tidb/parser/ast"
 	"github.com/pingcap/tidb/parser/charset"
 	"github.com/pingcap/tidb/parser/format"
@@ -4614,6 +4615,11 @@ func GetModifiableColumnJob(
 		return nil, err
 	}
 
+	err = checkColumnWithPartitionConstraint(sctx, t.Meta().Clone(), newCol.ColumnInfo.Clone(), col.ColumnInfo.Clone(), spec.Position)
+	if err != nil {
+		return nil, err
+	}
+
 	// As same with MySQL, we don't support modifying the stored status for generated columns.
 	if err = checkModifyGeneratedColumn(sctx, t, col, newCol, specNewColumn, spec.Position); err != nil {
 		return nil, errors.Trace(err)
@@ -4644,6 +4650,48 @@ func GetModifiableColumnJob(
 	return job, nil
 }
 
+// checkColumnWithPartitionConstraint is used to check the partition constraint of the modified column.
+func checkColumnWithPartitionConstraint(sctx sessionctx.Context, tbInfo *model.TableInfo, newCol, oldCol *model.ColumnInfo, pos *ast.ColumnPosition) error {
+	pi := tbInfo.GetPartitionInfo()
+	if pi == nil || pi.Expr == "" {
+		return nil
+	}
+
+	err := adjustTableInfoAfterModifyColumn(tbInfo, newCol, oldCol, pos)
+	if err != nil {
+		return errors.Trace(err)
+	}
+
+	exprStr := "select " + pi.Expr
+	var stmts []ast.StmtNode
+	if p, ok := sctx.(interface {
+		ParseSQL(context.Context, string, ...parser.ParseParam) ([]ast.StmtNode, []error, error)
+	}); ok {
+		stmts, _, err = p.ParseSQL(context.Background(), exprStr)
+	} else {
+		stmts, _, err = parser.New().ParseSQL(exprStr)
+	}
+
+	if err != nil {
+		return errors.Trace(err)
+	}
+
+	expr := stmts[0].(*ast.SelectStmt).Fields.Fields[0].Expr
+	e, err := expression.RewriteSimpleExprWithTableInfo(sctx, tbInfo, expr)
+	if err != nil {
+		return errors.Trace(err)
+	}
+
+	if e.GetType().EvalType() == types.ETInt {
+		return nil
+	}
+	if col, ok := expr.(*ast.ColumnNameExpr); ok {
+		return errors.Trace(dbterror.ErrNotAllowedTypeInPartition.GenWithStackByArgs(col.Name.Name.L))
+	}
+
+	return errors.Trace(dbterror.ErrPartitionFuncNotAllowed.GenWithStackByArgs("PARTITION"))
+}
+
 // checkColumnWithIndexConstraint is used to check the related index constraint of the modified column.
 // Index has a max-prefix-length constraint. eg: a varchar(100), index idx(a), modifying column a to a varchar(4000)
 // will cause index idx to break the max-prefix-length constraint.