package gorm import ( "fmt" "regexp" "strings" "gorm.io/gorm/clause" "gorm.io/gorm/utils" ) // Model specify the model you would like to run db operations // // // update all users's name to `hello` // db.Model(&User{}).Update("name", "hello") // // if user's primary key is non-blank, will use it as condition, then will only update that user's name to `hello` // db.Model(&user).Update("name", "hello") func (db *DB) Model(value interface{}) (tx *DB) { tx = db.getInstance() tx.Statement.Model = value return } // Clauses Add clauses // // This supports both standard clauses (clause.OrderBy, clause.Limit, clause.Where) and more // advanced techniques like specifying lock strength and optimizer hints. See the // [docs] for more depth. // // // add a simple limit clause // db.Clauses(clause.Limit{Limit: 1}).Find(&User{}) // // tell the optimizer to use the `idx_user_name` index // db.Clauses(hints.UseIndex("idx_user_name")).Find(&User{}) // // specify the lock strength to UPDATE // db.Clauses(clause.Locking{Strength: "UPDATE"}).Find(&users) // // [docs]: https://gorm.io/docs/sql_builder.html#Clauses func (db *DB) Clauses(conds ...clause.Expression) (tx *DB) { tx = db.getInstance() var whereConds []interface{} for _, cond := range conds { if c, ok := cond.(clause.Interface); ok { tx.Statement.AddClause(c) } else if optimizer, ok := cond.(StatementModifier); ok { optimizer.ModifyStatement(tx.Statement) } else { whereConds = append(whereConds, cond) } } if len(whereConds) > 0 { tx.Statement.AddClause(clause.Where{Exprs: tx.Statement.BuildCondition(whereConds[0], whereConds[1:]...)}) } return } var tableRegexp = regexp.MustCompile(`(?i)(?:.+? AS (\w+)\s*(?:$|,)|^\w+\s+(\w+)$)`) // Table specify the table you would like to run db operations // // // Get a user // db.Table("users").take(&result) func (db *DB) Table(name string, args ...interface{}) (tx *DB) { tx = db.getInstance() if strings.Contains(name, " ") || strings.Contains(name, "`") || len(args) > 0 { tx.Statement.TableExpr = &clause.Expr{SQL: name, Vars: args} if results := tableRegexp.FindStringSubmatch(name); len(results) == 3 { if results[1] != "" { tx.Statement.Table = results[1] } else { tx.Statement.Table = results[2] } } } else if tables := strings.Split(name, "."); len(tables) == 2 { tx.Statement.TableExpr = &clause.Expr{SQL: tx.Statement.Quote(name)} tx.Statement.Table = tables[1] } else if name != "" { tx.Statement.TableExpr = &clause.Expr{SQL: tx.Statement.Quote(name)} tx.Statement.Table = name } else { tx.Statement.TableExpr = nil tx.Statement.Table = "" } return } // Distinct specify distinct fields that you want querying // // // Select distinct names of users // db.Distinct("name").Find(&results) // // Select distinct name/age pairs from users // db.Distinct("name", "age").Find(&results) func (db *DB) Distinct(args ...interface{}) (tx *DB) { tx = db.getInstance() tx.Statement.Distinct = true if len(args) > 0 { tx = tx.Select(args[0], args[1:]...) } return } // Select specify fields that you want when querying, creating, updating // // Use Select when you only want a subset of the fields. By default, GORM will select all fields. // Select accepts both string arguments and arrays. // // // Select name and age of user using multiple arguments // db.Select("name", "age").Find(&users) // // Select name and age of user using an array // db.Select([]string{"name", "age"}).Find(&users) func (db *DB) Select(query interface{}, args ...interface{}) (tx *DB) { tx = db.getInstance() switch v := query.(type) { case []string: tx.Statement.Selects = v for _, arg := range args { switch arg := arg.(type) { case string: tx.Statement.Selects = append(tx.Statement.Selects, arg) case []string: tx.Statement.Selects = append(tx.Statement.Selects, arg...) default: tx.AddError(fmt.Errorf("unsupported select args %v %v", query, args)) return } } if clause, ok := tx.Statement.Clauses["SELECT"]; ok { clause.Expression = nil tx.Statement.Clauses["SELECT"] = clause } case string: if strings.Count(v, "?") >= len(args) && len(args) > 0 { tx.Statement.AddClause(clause.Select{ Distinct: db.Statement.Distinct, Expression: clause.Expr{SQL: v, Vars: args}, }) } else if strings.Count(v, "@") > 0 && len(args) > 0 { tx.Statement.AddClause(clause.Select{ Distinct: db.Statement.Distinct, Expression: clause.NamedExpr{SQL: v, Vars: args}, }) } else { tx.Statement.Selects = []string{v} for _, arg := range args { switch arg := arg.(type) { case string: tx.Statement.Selects = append(tx.Statement.Selects, arg) case []string: tx.Statement.Selects = append(tx.Statement.Selects, arg...) default: tx.Statement.AddClause(clause.Select{ Distinct: db.Statement.Distinct, Expression: clause.Expr{SQL: v, Vars: args}, }) return } } if clause, ok := tx.Statement.Clauses["SELECT"]; ok { clause.Expression = nil tx.Statement.Clauses["SELECT"] = clause } } default: tx.AddError(fmt.Errorf("unsupported select args %v %v", query, args)) } return } // Omit specify fields that you want to ignore when creating, updating and querying func (db *DB) Omit(columns ...string) (tx *DB) { tx = db.getInstance() if len(columns) == 1 && strings.ContainsRune(columns[0], ',') { tx.Statement.Omits = strings.FieldsFunc(columns[0], utils.IsValidDBNameChar) } else { tx.Statement.Omits = columns } return } // Where add conditions // // See the [docs] for details on the various formats that where clauses can take. By default, where clauses chain with AND. // // // Find the first user with name jinzhu // db.Where("name = ?", "jinzhu").First(&user) // // Find the first user with name jinzhu and age 20 // db.Where(&User{Name: "jinzhu", Age: 20}).First(&user) // // Find the first user with name jinzhu and age not equal to 20 // db.Where("name = ?", "jinzhu").Where("age <> ?", "20").First(&user) // // [docs]: https://gorm.io/docs/query.html#Conditions func (db *DB) Where(query interface{}, args ...interface{}) (tx *DB) { tx = db.getInstance() if conds := tx.Statement.BuildCondition(query, args...); len(conds) > 0 { tx.Statement.AddClause(clause.Where{Exprs: conds}) } return } // Not add NOT conditions // // Not works similarly to where, and has the same syntax. // // // Find the first user with name not equal to jinzhu // db.Not("name = ?", "jinzhu").First(&user) func (db *DB) Not(query interface{}, args ...interface{}) (tx *DB) { tx = db.getInstance() if conds := tx.Statement.BuildCondition(query, args...); len(conds) > 0 { tx.Statement.AddClause(clause.Where{Exprs: []clause.Expression{clause.Not(conds...)}}) } return } // Or add OR conditions // // Or is used to chain together queries with an OR. // // // Find the first user with name equal to jinzhu or john // db.Where("name = ?", "jinzhu").Or("name = ?", "john").First(&user) func (db *DB) Or(query interface{}, args ...interface{}) (tx *DB) { tx = db.getInstance() if conds := tx.Statement.BuildCondition(query, args...); len(conds) > 0 { tx.Statement.AddClause(clause.Where{Exprs: []clause.Expression{clause.Or(clause.And(conds...))}}) } return } // Joins specify Joins conditions // // db.Joins("Account").Find(&user) // db.Joins("JOIN emails ON emails.user_id = users.id AND emails.email = ?", "jinzhu@example.org").Find(&user) // db.Joins("Account", DB.Select("id").Where("user_id = users.id AND name = ?", "someName").Model(&Account{})) func (db *DB) Joins(query string, args ...interface{}) (tx *DB) { return joins(db, clause.LeftJoin, query, args...) } // InnerJoins specify inner joins conditions // db.InnerJoins("Account").Find(&user) func (db *DB) InnerJoins(query string, args ...interface{}) (tx *DB) { return joins(db, clause.InnerJoin, query, args...) } func joins(db *DB, joinType clause.JoinType, query string, args ...interface{}) (tx *DB) { tx = db.getInstance() if len(args) == 1 { if db, ok := args[0].(*DB); ok { j := join{ Name: query, Conds: args, Selects: db.Statement.Selects, Omits: db.Statement.Omits, JoinType: joinType, } if where, ok := db.Statement.Clauses["WHERE"].Expression.(clause.Where); ok { j.On = &where } tx.Statement.Joins = append(tx.Statement.Joins, j) return } } tx.Statement.Joins = append(tx.Statement.Joins, join{Name: query, Conds: args, JoinType: joinType}) return } // Group specify the group method on the find // // // Select the sum age of users with given names // db.Model(&User{}).Select("name, sum(age) as total").Group("name").Find(&results) func (db *DB) Group(name string) (tx *DB) { tx = db.getInstance() fields := strings.FieldsFunc(name, utils.IsValidDBNameChar) tx.Statement.AddClause(clause.GroupBy{ Columns: []clause.Column{{Name: name, Raw: len(fields) != 1}}, }) return } // Having specify HAVING conditions for GROUP BY // // // Select the sum age of users with name jinzhu // db.Model(&User{}).Select("name, sum(age) as total").Group("name").Having("name = ?", "jinzhu").Find(&result) func (db *DB) Having(query interface{}, args ...interface{}) (tx *DB) { tx = db.getInstance() tx.Statement.AddClause(clause.GroupBy{ Having: tx.Statement.BuildCondition(query, args...), }) return } // Order specify order when retrieving records from database // // db.Order("name DESC") // db.Order(clause.OrderByColumn{Column: clause.Column{Name: "name"}, Desc: true}) func (db *DB) Order(value interface{}) (tx *DB) { tx = db.getInstance() switch v := value.(type) { case clause.OrderByColumn: tx.Statement.AddClause(clause.OrderBy{ Columns: []clause.OrderByColumn{v}, }) case string: if v != "" { tx.Statement.AddClause(clause.OrderBy{ Columns: []clause.OrderByColumn{{ Column: clause.Column{Name: v, Raw: true}, }}, }) } } return } // Limit specify the number of records to be retrieved // // Limit conditions can be cancelled by using `Limit(-1)`. // // // retrieve 3 users // db.Limit(3).Find(&users) // // retrieve 3 users into users1, and all users into users2 // db.Limit(3).Find(&users1).Limit(-1).Find(&users2) func (db *DB) Limit(limit int) (tx *DB) { tx = db.getInstance() tx.Statement.AddClause(clause.Limit{Limit: &limit}) return } // Offset specify the number of records to skip before starting to return the records // // Offset conditions can be cancelled by using `Offset(-1)`. // // // select the third user // db.Offset(2).First(&user) // // select the first user by cancelling an earlier chained offset // db.Offset(5).Offset(-1).First(&user) func (db *DB) Offset(offset int) (tx *DB) { tx = db.getInstance() tx.Statement.AddClause(clause.Limit{Offset: offset}) return } // Scopes pass current database connection to arguments `func(DB) DB`, which could be used to add conditions dynamically // // func AmountGreaterThan1000(db *gorm.DB) *gorm.DB { // return db.Where("amount > ?", 1000) // } // // func OrderStatus(status []string) func (db *gorm.DB) *gorm.DB { // return func (db *gorm.DB) *gorm.DB { // return db.Scopes(AmountGreaterThan1000).Where("status in (?)", status) // } // } // // db.Scopes(AmountGreaterThan1000, OrderStatus([]string{"paid", "shipped"})).Find(&orders) func (db *DB) Scopes(funcs ...func(*DB) *DB) (tx *DB) { tx = db.getInstance() tx.Statement.scopes = append(tx.Statement.scopes, funcs...) return tx } func (db *DB) executeScopes() (tx *DB) { tx = db.getInstance() scopes := db.Statement.scopes if len(scopes) == 0 { return tx } tx.Statement.scopes = nil conditions := make([]clause.Interface, 0, 4) if cs, ok := tx.Statement.Clauses["WHERE"]; ok && cs.Expression != nil { conditions = append(conditions, cs.Expression.(clause.Interface)) cs.Expression = nil tx.Statement.Clauses["WHERE"] = cs } for _, scope := range scopes { tx = scope(tx) if cs, ok := tx.Statement.Clauses["WHERE"]; ok && cs.Expression != nil { conditions = append(conditions, cs.Expression.(clause.Interface)) cs.Expression = nil tx.Statement.Clauses["WHERE"] = cs } } for _, condition := range conditions { tx.Statement.AddClause(condition) } return tx } // Preload preload associations with given conditions // // // get all users, and preload all non-cancelled orders // db.Preload("Orders", "state NOT IN (?)", "cancelled").Find(&users) func (db *DB) Preload(query string, args ...interface{}) (tx *DB) { tx = db.getInstance() if tx.Statement.Preloads == nil { tx.Statement.Preloads = map[string][]interface{}{} } tx.Statement.Preloads[query] = args return } // Attrs provide attributes used in [FirstOrCreate] or [FirstOrInit] // // Attrs only adds attributes if the record is not found. // // // assign an email if the record is not found // db.Where(User{Name: "non_existing"}).Attrs(User{Email: "fake@fake.org"}).FirstOrInit(&user) // // user -> User{Name: "non_existing", Email: "fake@fake.org"} // // // assign an email if the record is not found, otherwise ignore provided email // db.Where(User{Name: "jinzhu"}).Attrs(User{Email: "fake@fake.org"}).FirstOrInit(&user) // // user -> User{Name: "jinzhu", Age: 20} // // [FirstOrCreate]: https://gorm.io/docs/advanced_query.html#FirstOrCreate // [FirstOrInit]: https://gorm.io/docs/advanced_query.html#FirstOrInit func (db *DB) Attrs(attrs ...interface{}) (tx *DB) { tx = db.getInstance() tx.Statement.attrs = attrs return } // Assign provide attributes used in [FirstOrCreate] or [FirstOrInit] // // Assign adds attributes even if the record is found. If using FirstOrCreate, this means that // records will be updated even if they are found. // // // assign an email regardless of if the record is not found // db.Where(User{Name: "non_existing"}).Assign(User{Email: "fake@fake.org"}).FirstOrInit(&user) // // user -> User{Name: "non_existing", Email: "fake@fake.org"} // // // assign email regardless of if record is found // db.Where(User{Name: "jinzhu"}).Assign(User{Email: "fake@fake.org"}).FirstOrInit(&user) // // user -> User{Name: "jinzhu", Age: 20, Email: "fake@fake.org"} // // [FirstOrCreate]: https://gorm.io/docs/advanced_query.html#FirstOrCreate // [FirstOrInit]: https://gorm.io/docs/advanced_query.html#FirstOrInit func (db *DB) Assign(attrs ...interface{}) (tx *DB) { tx = db.getInstance() tx.Statement.assigns = attrs return } func (db *DB) Unscoped() (tx *DB) { tx = db.getInstance() tx.Statement.Unscoped = true return } func (db *DB) Raw(sql string, values ...interface{}) (tx *DB) { tx = db.getInstance() tx.Statement.SQL = strings.Builder{} if strings.Contains(sql, "@") { clause.NamedExpr{SQL: sql, Vars: values}.Build(tx.Statement) } else { clause.Expr{SQL: sql, Vars: values}.Build(tx.Statement) } return }