gorm/chainable_api.go

250 lines
6.8 KiB
Go

package gorm
import (
"fmt"
"strings"
"github.com/jinzhu/gorm/clause"
"github.com/jinzhu/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 the 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
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 {
whereConds = append(whereConds, cond)
}
}
if len(whereConds) > 0 {
tx.Statement.AddClause(clause.Where{Exprs: tx.Statement.BuildCondtion(whereConds[0], whereConds[1:]...)})
}
return
}
// Table specify the table you would like to run db operations
func (db *DB) Table(name string) (tx *DB) {
tx = db.getInstance()
tx.Statement.Table = name
return
}
// Select specify fields that you want when querying, creating, updating
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
}
}
case string:
fields := strings.FieldsFunc(v, utils.IsChar)
// normal field names
if len(fields) == 1 || (len(fields) == 3 && strings.ToUpper(fields[1]) == "AS") {
tx.Statement.Selects = fields
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{
Expression: clause.Expr{SQL: v, Vars: args},
})
return
}
}
} else {
tx.Statement.AddClause(clause.Select{
Expression: clause.Expr{SQL: v, Vars: args},
})
}
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.IsChar)
} else {
tx.Statement.Omits = columns
}
return
}
// Where add conditions
func (db *DB) Where(query interface{}, args ...interface{}) (tx *DB) {
tx = db.getInstance()
tx.Statement.AddClause(clause.Where{Exprs: tx.Statement.BuildCondtion(query, args...)})
return
}
// Not add NOT conditions
func (db *DB) Not(query interface{}, args ...interface{}) (tx *DB) {
tx = db.getInstance()
tx.Statement.AddClause(clause.Where{Exprs: []clause.Expression{clause.Not(tx.Statement.BuildCondtion(query, args...)...)}})
return
}
// Or add OR conditions
func (db *DB) Or(query interface{}, args ...interface{}) (tx *DB) {
tx = db.getInstance()
tx.Statement.AddClause(clause.Where{Exprs: []clause.Expression{clause.Or(tx.Statement.BuildCondtion(query, args...)...)}})
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)
func (db *DB) Joins(query string, args ...interface{}) (tx *DB) {
tx = db.getInstance()
if tx.Statement.Joins == nil {
tx.Statement.Joins = map[string][]interface{}{}
}
tx.Statement.Joins[query] = args
return
}
// Group specify the group method on the find
func (db *DB) Group(name string) (tx *DB) {
tx = db.getInstance()
tx.Statement.AddClause(clause.GroupBy{
Columns: []clause.Column{{Name: name}},
})
return
}
// Having specify HAVING conditions for GROUP BY
func (db *DB) Having(query interface{}, args ...interface{}) (tx *DB) {
tx = db.getInstance()
tx.Statement.AddClause(clause.GroupBy{
Having: tx.Statement.BuildCondtion(query, args...),
})
return
}
// Order specify order when retrieve records from database
// db.Order("name DESC")
// db.Order(gorm.Expr("name = ? DESC", "first")) // sql expression
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},
})
default:
tx.Statement.AddClause(clause.OrderBy{
Columns: []clause.OrderByColumn{{
Column: clause.Column{Name: fmt.Sprint(value), Raw: true},
}},
})
}
return
}
// Limit specify the number of records to be retrieved
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
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) *DB {
for _, f := range funcs {
db = f(db)
}
return db
}
// Preload preload associations with given conditions
// 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
}
func (db *DB) Attrs(attrs ...interface{}) (tx *DB) {
tx = db.getInstance()
tx.Statement.attrs = attrs
return
}
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()
return
}
func (db *DB) Raw(sql string, values ...interface{}) (tx *DB) {
tx = db.getInstance()
tx.Statement.SQL = strings.Builder{}
clause.Expr{SQL: sql, Vars: values}.Build(tx.Statement)
return
}