(WIP) Implement Generics API

callbacks/create.go

@@ -89,6 +89,10 @@ func Create(config *Config) func(db *gorm.DB) {
 					db.AddError(rows.Close())
 				}()
 				gorm.Scan(rows, db, mode)
+
+				if db.Statement.Result != nil {
+					db.Statement.Result.RowsAffected = db.RowsAffected
+				}
 			}
 
 			return
@@ -103,6 +107,12 @@ func Create(config *Config) func(db *gorm.DB) {
 		}
 
 		db.RowsAffected, _ = result.RowsAffected()
+
+		if db.Statement.Result != nil {
+			db.Statement.Result.Result = result
+			db.Statement.Result.RowsAffected = db.RowsAffected
+		}
+
 		if db.RowsAffected == 0 {
 			return
 		}

callbacks/delete.go

@@ -157,15 +157,25 @@ func Delete(config *Config) func(db *gorm.DB) {
 			ok, mode := hasReturning(db, supportReturning)
 			if !ok {
 				result, err := db.Statement.ConnPool.ExecContext(db.Statement.Context, db.Statement.SQL.String(), db.Statement.Vars...)
+
 				if db.AddError(err) == nil {
 					db.RowsAffected, _ = result.RowsAffected()
+
+					if db.Statement.Result != nil {
+						db.Statement.Result.Result = result
+						db.Statement.Result.RowsAffected = db.RowsAffected
+					}
 				}
 
 				return
 			}
 
 			if rows, err := db.Statement.ConnPool.QueryContext(db.Statement.Context, db.Statement.SQL.String(), db.Statement.Vars...); db.AddError(err) == nil {
 				gorm.Scan(rows, db, mode)
+
+				if db.Statement.Result != nil {
+					db.Statement.Result.RowsAffected = db.RowsAffected
+				}
 				db.AddError(rows.Close())
 			}
 		}

callbacks/preload.go

@@ -275,6 +275,8 @@ func preload(tx *gorm.DB, rel *schema.Relationship, conds []interface{}, preload
 	column, values := schema.ToQueryValues(clause.CurrentTable, relForeignKeys, foreignValues)
 
 	if len(values) != 0 {
+		tx = tx.Model(reflectResults.Addr().Interface()).Where(clause.IN{Column: column, Values: values})
+
 		for _, cond := range conds {
 			if fc, ok := cond.(func(*gorm.DB) *gorm.DB); ok {
 				tx = fc(tx)
@@ -283,7 +285,11 @@ func preload(tx *gorm.DB, rel *schema.Relationship, conds []interface{}, preload
 			}
 		}
 
-		if err := tx.Where(clause.IN{Column: column, Values: values}).Find(reflectResults.Addr().Interface(), inlineConds...).Error; err != nil {
+		if len(inlineConds) > 0 {
+			tx = tx.Where(inlineConds[0], inlineConds[1:]...)
+		}
+
+		if err := tx.Find(reflectResults.Addr().Interface()).Error; err != nil {
 			return err
 		}
 	}

callbacks/query.go

@@ -25,6 +25,10 @@ func Query(db *gorm.DB) {
 				db.AddError(rows.Close())
 			}()
 			gorm.Scan(rows, db, 0)
+
+			if db.Statement.Result != nil {
+				db.Statement.Result.RowsAffected = db.RowsAffected
+			}
 		}
 	}
 }
@@ -110,7 +114,7 @@ func BuildQuerySQL(db *gorm.DB) {
 				}
 			}
 
-			specifiedRelationsName := make(map[string]interface{})
+			specifiedRelationsName := map[string]string{clause.CurrentTable: clause.CurrentTable}
 			for _, join := range db.Statement.Joins {
 				if db.Statement.Schema != nil {
 					var isRelations bool // is relations or raw sql
@@ -124,12 +128,12 @@ func BuildQuerySQL(db *gorm.DB) {
 						nestedJoinNames := strings.Split(join.Name, ".")
 						if len(nestedJoinNames) > 1 {
 							isNestedJoin := true
-							gussNestedRelations := make([]*schema.Relationship, 0, len(nestedJoinNames))
+							guessNestedRelations := make([]*schema.Relationship, 0, len(nestedJoinNames))
 							currentRelations := db.Statement.Schema.Relationships.Relations
 							for _, relname := range nestedJoinNames {
 								// incomplete match, only treated as raw sql
 								if relation, ok = currentRelations[relname]; ok {
-									gussNestedRelations = append(gussNestedRelations, relation)
+									guessNestedRelations = append(guessNestedRelations, relation)
 									currentRelations = relation.FieldSchema.Relationships.Relations
 								} else {
 									isNestedJoin = false
@@ -139,18 +143,13 @@ func BuildQuerySQL(db *gorm.DB) {
 
 							if isNestedJoin {
 								isRelations = true
-								relations = gussNestedRelations
+								relations = guessNestedRelations
 							}
 						}
 					}
 
 					if isRelations {
-						genJoinClause := func(joinType clause.JoinType, parentTableName string, relation *schema.Relationship) clause.Join {
-							tableAliasName := relation.Name
-							if parentTableName != clause.CurrentTable {
-								tableAliasName = utils.NestedRelationName(parentTableName, tableAliasName)
-							}
-
+						genJoinClause := func(joinType clause.JoinType, tableAliasName string, parentTableName string, relation *schema.Relationship) clause.Join {
 							columnStmt := gorm.Statement{
 								Table: tableAliasName, DB: db, Schema: relation.FieldSchema,
 								Selects: join.Selects, Omits: join.Omits,
@@ -167,6 +166,13 @@ func BuildQuerySQL(db *gorm.DB) {
 								}
 							}
 
+							if join.Expression != nil {
+								return clause.Join{
+									Type:       join.JoinType,
+									Expression: join.Expression,
+								}
+							}
+
 							exprs := make([]clause.Expression, len(relation.References))
 							for idx, ref := range relation.References {
 								if ref.OwnPrimaryKey {
@@ -226,19 +232,24 @@ func BuildQuerySQL(db *gorm.DB) {
 						}
 
 						parentTableName := clause.CurrentTable
-						for _, rel := range relations {
+						for idx, rel := range relations {
 							// joins table alias like "Manager, Company, Manager__Company"
-							nestedAlias := utils.NestedRelationName(parentTableName, rel.Name)
-							if _, ok := specifiedRelationsName[nestedAlias]; !ok {
-								fromClause.Joins = append(fromClause.Joins, genJoinClause(join.JoinType, parentTableName, rel))
-								specifiedRelationsName[nestedAlias] = nil
+							curAliasName := rel.Name
+							if parentTableName != clause.CurrentTable {
+								curAliasName = utils.NestedRelationName(parentTableName, curAliasName)
 							}
 
-							if parentTableName != clause.CurrentTable {
-								parentTableName = utils.NestedRelationName(parentTableName, rel.Name)
-							} else {
-								parentTableName = rel.Name
+							if _, ok := specifiedRelationsName[curAliasName]; !ok {
+								aliasName := curAliasName
+								if idx == len(relations)-1 && join.Alias != "" {
+									aliasName = join.Alias
+								}
+
+								fromClause.Joins = append(fromClause.Joins, genJoinClause(join.JoinType, aliasName, specifiedRelationsName[parentTableName], rel))
+								specifiedRelationsName[curAliasName] = aliasName
 							}
+
+							parentTableName = curAliasName
 						}
 					} else {
 						fromClause.Joins = append(fromClause.Joins, clause.Join{

callbacks/raw.go

@@ -13,5 +13,10 @@ func RawExec(db *gorm.DB) {
 		}
 
 		db.RowsAffected, _ = result.RowsAffected()
+
+		if db.Statement.Result != nil {
+			db.Statement.Result.Result = result
+			db.Statement.Result.RowsAffected = db.RowsAffected
+		}
 	}
 }

callbacks/update.go

@@ -92,13 +92,22 @@ func Update(config *Config) func(db *gorm.DB) {
 					gorm.Scan(rows, db, mode)
 					db.Statement.Dest = dest
 					db.AddError(rows.Close())
+
+					if db.Statement.Result != nil {
+						db.Statement.Result.RowsAffected = db.RowsAffected
+					}
 				}
 			} else {
 				result, err := db.Statement.ConnPool.ExecContext(db.Statement.Context, db.Statement.SQL.String(), db.Statement.Vars...)
 
 				if db.AddError(err) == nil {
 					db.RowsAffected, _ = result.RowsAffected()
 				}
+
+				if db.Statement.Result != nil {
+					db.Statement.Result.Result = result
+					db.Statement.Result.RowsAffected = db.RowsAffected
+				}
 			}
 		}
 	}

chainable_api.go

@@ -448,9 +448,10 @@ func (db *DB) Assign(attrs ...interface{}) (tx *DB) {
 // Unscoped allows queries to include records marked as deleted,
 // overriding the soft deletion behavior.
 // Example:
-//    var users []User
-//    db.Unscoped().Find(&users)
-//    // Retrieves all users, including deleted ones.
+//
+//	var users []User
+//	db.Unscoped().Find(&users)
+//	// Retrieves all users, including deleted ones.
 func (db *DB) Unscoped() (tx *DB) {
 	tx = db.getInstance()
 	tx.Statement.Unscoped = true

clause/joins.go

@@ -1,5 +1,7 @@
 package clause
 
+import "gorm.io/gorm/utils"
+
 type JoinType string
 
 const (
@@ -9,6 +11,30 @@ const (
 	RightJoin JoinType = "RIGHT"
 )
 
+type JoinTarget struct {
+	Type        JoinType
+	Association string
+	Subquery    Expression
+	Table       string
+}
+
+func Has(name string) JoinTarget {
+	return JoinTarget{Type: InnerJoin, Association: name}
+}
+
+func (jt JoinType) Association(name string) JoinTarget {
+	return JoinTarget{Type: jt, Association: name}
+}
+
+func (jt JoinType) AssociationFrom(name string, subquery Expression) JoinTarget {
+	return JoinTarget{Type: jt, Association: name, Subquery: subquery}
+}
+
+func (jt JoinTarget) As(name string) JoinTarget {
+	jt.Table = name
+	return jt
+}
+
 // Join clause for from
 type Join struct {
 	Type       JoinType
@@ -18,6 +44,12 @@ type Join struct {
 	Expression Expression
 }
 
+func JoinTable(names ...string) Table {
+	return Table{
+		Name: utils.JoinNestedRelationNames(names),
+	}
+}
+
 func (join Join) Build(builder Builder) {
 	if join.Expression != nil {
 		join.Expression.Build(builder)

finisher_api.go

@@ -1,6 +1,7 @@
 package gorm
 
 import (
+	"context"
 	"database/sql"
 	"errors"
 	"fmt"
@@ -673,11 +674,18 @@
 		opt = opts[0]
 	}
 
+	ctx := tx.Statement.Context
+	if _, ok := ctx.Deadline(); !ok {
+		if db.Config.DefaultTransactionTimeout > 0 {
+			ctx, _ = context.WithTimeout(ctx, db.Config.DefaultTransactionTimeout)
+		}
+	}
+
 	switch beginner := tx.Statement.ConnPool.(type) {
 	case TxBeginner:
-		tx.Statement.ConnPool, err = beginner.BeginTx(tx.Statement.Context, opt)
+		tx.Statement.ConnPool, err = beginner.BeginTx(ctx, opt)
 	case ConnPoolBeginner:
-		tx.Statement.ConnPool, err = beginner.BeginTx(tx.Statement.Context, opt)
+		tx.Statement.ConnPool, err = beginner.BeginTx(ctx, opt)
 	default:
 		err = ErrInvalidTransaction
 	}