Drop existing default on Users.Timezone prior to column type change (#18669)

store/sqlstore/store.go

@@ -133,6 +133,7 @@ type SqlStore struct {
 // ColumnInfo holds information about a column.
 type ColumnInfo struct {
 	DataType          string
+	DefaultValue      string
 	CharMaximumLength int
 }
 
@@ -651,7 +652,7 @@ func (ss *SqlStore) GetColumnInfo(tableName, columnName string) (*ColumnInfo, er
 	var columnInfo ColumnInfo
 	if ss.DriverName() == model.DatabaseDriverPostgres {
 		err := ss.GetMaster().SelectOne(&columnInfo,
-			`SELECT data_type as DataType,
+			`SELECT data_type as DataType, COALESCE(column_default, '') as DefaultValue,
 					COALESCE(character_maximum_length, 0) as CharMaximumLength
 			 FROM information_schema.columns
 			 WHERE lower(table_name) = lower($1)
@@ -663,7 +664,7 @@ func (ss *SqlStore) GetColumnInfo(tableName, columnName string) (*ColumnInfo, er
 		return &columnInfo, nil
 	} else if ss.DriverName() == model.DatabaseDriverMysql {
 		err := ss.GetMaster().SelectOne(&columnInfo,
-			`SELECT data_type as DataType,
+			`SELECT data_type as DataType, COALESCE(column_default, '') as DefaultValue,
 					COALESCE(character_maximum_length, 0) as CharMaximumLength
 			 FROM information_schema.columns
 			 WHERE table_schema = DATABASE()

store/sqlstore/upgrade.go

@@ -1301,7 +1301,6 @@ func upgradeDatabaseToVersion539(sqlStore *SqlStore) {
 
 func upgradeDatabaseToVersion600(sqlStore *SqlStore) {
 	if shouldPerformUpgrade(sqlStore, Version5390, Version600) {
-
 		sqlStore.GetMaster().ExecNoTimeout("UPDATE Posts SET RootId = ParentId WHERE RootId = '' AND RootId != ParentId")
 		if sqlStore.DriverName() == model.DatabaseDriverMysql {
 			if sqlStore.DoesColumnExist("Posts", "ParentId") {
@@ -1323,6 +1322,16 @@ func upgradeDatabaseToVersion600(sqlStore *SqlStore) {
 		sqlStore.AlterColumnTypeIfExists("Threads", "Participants", "JSON", "jsonb")
 		sqlStore.AlterColumnTypeIfExists("Users", "Props", "JSON", "jsonb")
 		sqlStore.AlterColumnTypeIfExists("Users", "NotifyProps", "JSON", "jsonb")
+		info, err := sqlStore.GetColumnInfo("Users", "Timezone")
+		if err != nil {
+			mlog.Error("Error getting column info",
+				mlog.String("table", "Users"),
+				mlog.String("column", "Timezone"),
+				mlog.Err(err),
+			)
+		} else if info.DefaultValue != "" {
+			sqlStore.RemoveDefaultIfColumnExists("Users", "Timezone")
+		}
 		sqlStore.AlterColumnTypeIfExists("Users", "Timezone", "JSON", "jsonb")
 
 		sqlStore.GetMaster().ExecNoTimeout("UPDATE CommandWebhooks SET RootId = ParentId WHERE RootId = '' AND RootId != ParentId")