diff --git a/migrator/migrator.go b/migrator/migrator.go
index 03ffdd02..da9ddd49 100644
--- a/migrator/migrator.go
+++ b/migrator/migrator.go
@@ -2,9 +2,11 @@ package migrator
 
 import (
 	"context"
+	"database/sql"
 	"fmt"
 	"reflect"
 	"regexp"
+	"strconv"
 	"strings"
 
 	"gorm.io/gorm"
@@ -155,7 +157,8 @@ func (m Migrator) AutoMigrate(values ...interface{}) error {
 }
 
 func (m Migrator) CreateTable(values ...interface{}) error {
-	for _, value := range m.ReorderModels(values, false) {
+	results := m.ReorderModels(values, false)
+	for _, value := range results {
 		tx := m.DB.Session(&gorm.Session{})
 		if err := m.RunWithValue(value, func(stmt *gorm.Statement) (errr error) {
 			var (
@@ -206,12 +209,10 @@ func (m Migrator) CreateTable(values ...interface{}) error {
 
 			for _, rel := range stmt.Schema.Relationships.Relations {
 				if !m.DB.DisableForeignKeyConstraintWhenMigrating {
-					if constraint := rel.ParseConstraint(); constraint != nil {
-						if constraint.Schema == stmt.Schema {
-							sql, vars := buildConstraint(constraint)
-							createTableSQL += sql + ","
-							values = append(values, vars...)
-						}
+					if constraint := rel.ParseConstraint(); constraint != nil && constraint.Schema == stmt.Schema {
+						sql, vars := buildConstraint(constraint)
+						createTableSQL += sql + ","
+						values = append(values, vars...)
 					}
 				}
 			}
@@ -221,10 +222,7 @@ func (m Migrator) CreateTable(values ...interface{}) error {
 				values = append(values, clause.Column{Name: chk.Name}, clause.Expr{SQL: chk.Constraint})
 			}
 
-			createTableSQL = strings.TrimSuffix(createTableSQL, ",")
-
-			createTableSQL += ")"
-
+			createTableSQL = strings.TrimSuffix(createTableSQL, ",") + ")"
 			if tableOption, ok := m.DB.Get("gorm:table_options"); ok {
 				createTableSQL += fmt.Sprint(tableOption)
 			}
@@ -382,29 +380,26 @@ func (m Migrator) MigrateColumn(value interface{}, field *schema.Field, columnTy
 			alterColumn = true
 		} else {
 			// has size in data type and not equal
-
 			// Since the following code is frequently called in the for loop, reg optimization is needed here
 			matches := regRealDataType.FindAllStringSubmatch(realDataType, -1)
 			matches2 := regFullDataType.FindAllStringSubmatch(fullDataType, -1)
-			if (len(matches) == 1 && matches[0][1] != fmt.Sprint(field.Size) || !field.PrimaryKey) && (len(matches2) == 1 && matches2[0][1] != fmt.Sprint(length)) {
+			if (len(matches) == 1 && matches[0][1] != strconv.Itoa(field.Size) || !field.PrimaryKey) &&
+				(len(matches2) == 1 && matches2[0][1] != strconv.FormatInt(length, 10)) {
 				alterColumn = true
 			}
 		}
 	}
 
 	// check precision
-	if precision, _, ok := columnType.DecimalSize(); ok && int64(field.Precision) != precision {
-		if regexp.MustCompile(fmt.Sprintf("[^0-9]%d[^0-9]", field.Precision)).MatchString(m.DataTypeOf(field)) {
-			alterColumn = true
-		}
+	if precision, _, ok := columnType.DecimalSize(); ok && int64(field.Precision) != precision &&
+		regexp.MustCompile(fmt.Sprintf("[^0-9]%d[^0-9]", field.Precision)).MatchString(m.DataTypeOf(field)) {
+		alterColumn = true
 	}
 
 	// check nullable
-	if nullable, ok := columnType.Nullable(); ok && nullable == field.NotNull {
+	if nullable, ok := columnType.Nullable(); ok && nullable == field.NotNull && !field.PrimaryKey && nullable {
 		// not primary key & database is nullable
-		if !field.PrimaryKey && nullable {
-			alterColumn = true
-		}
+		alterColumn = true
 	}
 
 	if alterColumn && !field.IgnoreMigration {
@@ -414,22 +409,30 @@ func (m Migrator) MigrateColumn(value interface{}, field *schema.Field, columnTy
 	return nil
 }
 
-func (m Migrator) ColumnTypes(value interface{}) (columnTypes []gorm.ColumnType, err error) {
-	columnTypes = make([]gorm.ColumnType, 0)
-	err = m.RunWithValue(value, func(stmt *gorm.Statement) error {
+func (m Migrator) ColumnTypes(value interface{}) ([]gorm.ColumnType, error) {
+	columnTypes := make([]gorm.ColumnType, 0)
+	execErr := m.RunWithValue(value, func(stmt *gorm.Statement) error {
 		rows, err := m.DB.Session(&gorm.Session{}).Table(stmt.Table).Limit(1).Rows()
-		if err == nil {
-			defer rows.Close()
-			rawColumnTypes, err := rows.ColumnTypes()
-			if err == nil {
-				for _, c := range rawColumnTypes {
-					columnTypes = append(columnTypes, c)
-				}
-			}
+		if err != nil {
+			return err
 		}
-		return err
+
+		defer rows.Close()
+
+		var rawColumnTypes []*sql.ColumnType
+		rawColumnTypes, err = rows.ColumnTypes()
+		if err != nil {
+			return err
+		}
+
+		for _, c := range rawColumnTypes {
+			columnTypes = append(columnTypes, c)
+		}
+
+		return nil
 	})
-	return
+
+	return columnTypes, execErr
 }
 
 func (m Migrator) CreateView(name string, option gorm.ViewOption) error {
@@ -608,7 +611,7 @@ func (m Migrator) CreateIndex(value interface{}, name string) error {
 			return m.DB.Exec(createIndexSQL, values...).Error
 		}
 
-		return fmt.Errorf("failed to create index with name %v", name)
+		return fmt.Errorf("failed to create index with name %s", name)
 	})
 }