Grow SQL capacity to reduce allocation

callbacks/create.go

@@ -42,6 +42,7 @@ func Create(config *Config) func(db *gorm.DB) {
 				}
 
 				if db.Statement.SQL.String() == "" {
+					db.Statement.SQL.Grow(180)
 					db.Statement.AddClauseIfNotExists(clause.Insert{
 						Table: clause.Table{Name: db.Statement.Table},
 					})
@@ -211,6 +212,7 @@ func ConvertToCreateValues(stmt *gorm.Statement) clause.Values {
 
 		switch stmt.ReflectValue.Kind() {
 		case reflect.Slice, reflect.Array:
+			stmt.SQL.Grow(stmt.ReflectValue.Len() * 15)
 			values.Values = make([][]interface{}, stmt.ReflectValue.Len())
 			defaultValueFieldsHavingValue := map[string][]interface{}{}
 			for i := 0; i < stmt.ReflectValue.Len(); i++ {

callbacks/delete.go

@@ -30,6 +30,7 @@ func Delete(db *gorm.DB) {
 		}
 
 		if db.Statement.SQL.String() == "" {
+			db.Statement.SQL.Grow(100)
 			db.Statement.AddClauseIfNotExists(clause.Delete{})
 
 			if db.Statement.Schema != nil {

callbacks/query.go

@@ -37,6 +37,7 @@ func Query(db *gorm.DB) {
 }
 
 func BuildQuerySQL(db *gorm.DB) {
+	db.Statement.SQL.Grow(100)
 	clauseSelect := clause.Select{Distinct: db.Statement.Distinct}
 
 	if db.Statement.ReflectValue.Kind() == reflect.Struct {

callbacks/update.go

@@ -59,6 +59,7 @@ func Update(db *gorm.DB) {
 		}
 
 		if db.Statement.SQL.String() == "" {
+			db.Statement.SQL.Grow(180)
 			db.Statement.AddClauseIfNotExists(clause.Update{})
 			if set := ConvertToAssignments(db.Statement); len(set) != 0 {
 				db.Statement.AddClause(set)