MariaDB always use null as default value

commit 22fde3a755dfab3c9a9dc1a73e797771e37302ff
Author: Jinzhu <wosmvp@gmail.com>
Date:   Sat May 28 22:59:11 2022 +0800

    Add don't support null as default value config

commit 195eea7
Author: a631807682 <631807682@qq.com>
Date:   Mon May 23 21:05:34 2022 +0800

    refactor: add config for mariadb default value

commit 4e5537b
Author: a631807682 <631807682@qq.com>
Date:   Fri May 20 21:07:25 2022 +0800

    fix: rewrite mariadb default value

migrator.go

@@ -203,6 +203,13 @@ func (m Migrator) ColumnTypes(value interface{}) ([]gorm.ColumnType, error) {
 			}
 
 			column.DefaultValueValue.String = strings.Trim(column.DefaultValueValue.String, "'")
+			if m.Dialector.DontSupportNullAsDefaultValue {
+				// rewrite mariadb default value like other version
+				if column.DefaultValueValue.Valid && column.DefaultValueValue.String == "NULL" {
+					column.DefaultValueValue.Valid = false
+					column.DefaultValueValue.String = ""
+				}
+			}
 
 			if datetimePrecision.Valid {
 				column.DecimalSizeValue = datetimePrecision

mysql.go

@@ -18,17 +18,18 @@ import (
 )
 
 type Config struct {
-	DriverName                string
-	ServerVersion             string
-	DSN                       string
-	Conn                      gorm.ConnPool
-	SkipInitializeWithVersion bool
-	DefaultStringSize         uint
-	DefaultDatetimePrecision  *int
-	DisableDatetimePrecision  bool
-	DontSupportRenameIndex    bool
-	DontSupportRenameColumn   bool
-	DontSupportForShareClause bool
+	DriverName                    string
+	ServerVersion                 string
+	DSN                           string
+	Conn                          gorm.ConnPool
+	SkipInitializeWithVersion     bool
+	DefaultStringSize             uint
+	DefaultDatetimePrecision      *int
+	DisableDatetimePrecision      bool
+	DontSupportRenameIndex        bool
+	DontSupportRenameColumn       bool
+	DontSupportForShareClause     bool
+	DontSupportNullAsDefaultValue bool
 }
 
 type Dialector struct {
@@ -120,6 +121,7 @@ func (dialector Dialector) Initialize(db *gorm.DB) (err error) {
 			dialector.Config.DontSupportRenameIndex = true
 			dialector.Config.DontSupportRenameColumn = true
 			dialector.Config.DontSupportForShareClause = true
+			dialector.Config.DontSupportNullAsDefaultValue = true
 		} else if strings.HasPrefix(dialector.ServerVersion, "5.6.") {
 			dialector.Config.DontSupportRenameIndex = true
 			dialector.Config.DontSupportRenameColumn = true