stats: use GetColOriginDefaultValue to get default value of a column (pingcap#60438)

close pingcap#60194

Author: YangKeao

pkg/statistics/handle/storage/BUILD.bazel

@@ -33,6 +33,7 @@ go_library(
         "//pkg/statistics/handle/usage/predicatecolumn",
         "//pkg/statistics/handle/util",
         "//pkg/statistics/util",
+        "//pkg/table",
         "//pkg/types",
         "//pkg/util/chunk",
         "//pkg/util/compress",

pkg/statistics/handle/storage/save.go

@@ -29,6 +29,7 @@ import (
 	"github.com/pingcap/tidb/pkg/statistics"
 	statslogutil "github.com/pingcap/tidb/pkg/statistics/handle/logutil"
 	"github.com/pingcap/tidb/pkg/statistics/handle/util"
+	"github.com/pingcap/tidb/pkg/table"
 	"github.com/pingcap/tidb/pkg/types"
 	"github.com/pingcap/tidb/pkg/util/chunk"
 	"github.com/pingcap/tidb/pkg/util/sqlescape"
@@ -444,8 +445,7 @@ func InsertColStats2KV(
 	}
 	count := req.GetRow(0).GetInt64(0)
 	for _, colInfo := range colInfos {
-		value := types.NewDatum(colInfo.GetOriginDefaultValue())
-		value, err = value.ConvertTo(sctx.GetSessionVars().StmtCtx.TypeCtx(), &colInfo.FieldType)
+		value, err := table.GetColOriginDefaultValue(sctx.GetExprCtx(), colInfo)
 		if err != nil {
 			return 0, errors.Trace(err)
 		}

tests/integrationtest/r/statistics/handle.result

@@ -79,3 +79,14 @@ insert into t values(1,1),(2,2),(3,3);
 alter table t add stats_extended s1 correlation(a,b);
 analyze table t;
 set session tidb_enable_extended_stats = default;
+drop table if exists t;
+set time_zone = '+08:00';
+create table t(a int);
+alter table t add column ts timestamp DEFAULT '1970-01-01 08:00:01';
+drop table if exists t;
+set time_zone = '+09:00';
+create table t(a int);
+alter table t add column ts timestamp DEFAULT '1970-01-01 08:00:01';
+Error 1067 (42000): Invalid default value for 'ts'
+drop table if exists t;
+set time_zone = default;

tests/integrationtest/t/statistics/handle.test

@@ -82,3 +82,16 @@ alter table t add stats_extended s1 correlation(a,b);
 ## no error
 analyze table t;
 set session tidb_enable_extended_stats = default;
+
+# TestHandleDDLEventForTimestampDefaultValue
+drop table if exists t;
+set time_zone = '+08:00';
+create table t(a int);
+alter table t add column ts timestamp DEFAULT '1970-01-01 08:00:01';
+drop table if exists t;
+set time_zone = '+09:00';
+create table t(a int);
+-- error 1067
+alter table t add column ts timestamp DEFAULT '1970-01-01 08:00:01';
+drop table if exists t;
+set time_zone = default;