diff --git a/.gitignore b/.gitignore
index 912d58f7..c14d6005 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,4 +1,4 @@
-TODO
+TODO*
 documents
 coverage.txt
 _book
diff --git a/association.go b/association.go
new file mode 100644
index 00000000..17f8f4a5
--- /dev/null
+++ b/association.go
@@ -0,0 +1,5 @@
+package gorm
+
+// Association Mode contains some helper methods to handle relationship things easily.
+type Association struct {
+}
diff --git a/chainable_api.go b/chainable_api.go
new file mode 100644
index 00000000..d8f2116c
--- /dev/null
+++ b/chainable_api.go
@@ -0,0 +1,138 @@
+package gorm
+
+// 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()
+	return
+}
+
+// Table specify the table you would like to run db operations
+func (db *DB) Table(name string) (tx *DB) {
+	tx = db.getInstance()
+	return
+}
+
+// Select specify fields that you want when querying, creating, updating
+func (db *DB) Select(query interface{}, args ...interface{}) (tx *DB) {
+	tx = db.getInstance()
+	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()
+	return
+}
+
+func (db *DB) Where(query interface{}, args ...interface{}) (tx *DB) {
+	tx = db.getInstance()
+	return
+}
+
+// Not add NOT condition
+func (db *DB) Not(query interface{}, args ...interface{}) (tx *DB) {
+	tx = db.getInstance()
+	return
+}
+
+// Or add OR conditions
+func (db *DB) Or(query interface{}, args ...interface{}) (tx *DB) {
+	tx = db.getInstance()
+	return
+}
+
+// Joins specify Joins conditions
+//     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()
+	return
+}
+
+// Group specify the group method on the find
+func (db *DB) Group(column string) (tx *DB) {
+	tx = db.getInstance()
+	return
+}
+
+// Having specify HAVING conditions for GROUP BY
+func (db *DB) Having(query interface{}, args ...interface{}) (tx *DB) {
+	tx = db.getInstance()
+	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()
+	return
+}
+
+// Limit specify the number of records to be retrieved
+func (db *DB) Limit(limit int64) (tx *DB) {
+	tx = db.getInstance()
+	return
+}
+
+// Offset specify the number of records to skip before starting to return the records
+func (db *DB) Offset(offset int64) (tx *DB) {
+	tx = db.getInstance()
+	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)
+// Refer https://jinzhu.github.io/gorm/crud.html#scopes
+func (db *DB) Scopes(funcs ...func(*DB) *DB) (tx *DB) {
+	for _, f := range funcs {
+		db = f(db)
+	}
+	return db
+}
+
+//Preloads only preloads relations, don`t touch out
+func (db *DB) Preloads(out interface{}) (tx *DB) {
+	tx = db.getInstance()
+	return
+}
+
+// Preload preload associations with given conditions
+//    db.Preload("Orders", "state NOT IN (?)", "cancelled").Find(&users)
+func (db *DB) Preload(column string, conditions ...interface{}) (tx *DB) {
+	tx = db.getInstance()
+	return
+}
+
+func (db *DB) Assign(attrs ...interface{}) (tx *DB) {
+	tx = db.getInstance()
+	return
+}
+
+func (db *DB) Attrs(attrs ...interface{}) (tx *DB) {
+	tx = db.getInstance()
+	return
+}
+
+func (db *DB) Unscoped() (tx *DB) {
+	tx = db.getInstance()
+	return
+}
+
+func (db *DB) Raw(sql string, values ...interface{}) (tx *DB) {
+	tx = db.getInstance()
+	return
+}
diff --git a/clause/clause.go b/clause/clause.go
new file mode 100644
index 00000000..4495a9d5
--- /dev/null
+++ b/clause/clause.go
@@ -0,0 +1,53 @@
+package clause
+
+// Builder builder interface
+type BuilderInterface interface {
+	Write(sql ...string) error
+	WriteQuoted(field interface{}) error
+	AddVar(vars ...interface{}) string
+	Quote(field interface{}) string
+}
+
+// Interface clause interface
+type Interface interface {
+	Name() string
+	Build(builder BuilderInterface)
+}
+
+// NegationBuilder negation condition builder
+type NegationBuilder interface {
+	NegationBuild(builder BuilderInterface)
+}
+
+// Where where clause
+type Where struct {
+}
+
+// Select select attrs when querying, updating, creating
+type Select struct {
+	Omit bool
+}
+
+// Join join clause
+type Join struct {
+}
+
+// GroupBy group by clause
+type GroupBy struct {
+}
+
+// Having having clause
+type Having struct {
+}
+
+// Order order clause
+type Order struct {
+}
+
+// Limit limit clause
+type Limit struct {
+}
+
+// Offset offset clause
+type Offset struct {
+}
diff --git a/clause/expr.go b/clause/expr.go
new file mode 100644
index 00000000..94edb702
--- /dev/null
+++ b/clause/expr.go
@@ -0,0 +1,19 @@
+package clause
+
+type ExprInterface interface {
+}
+
+type Expr struct {
+}
+
+type Average struct {
+}
+
+type Minimum struct {
+}
+
+type Maximum struct {
+}
+
+type Sum struct {
+}
diff --git a/clause/operators.go b/clause/operators.go
new file mode 100644
index 00000000..331abea7
--- /dev/null
+++ b/clause/operators.go
@@ -0,0 +1,195 @@
+package clause
+
+import "strings"
+
+type AddConditions []Interface
+
+func (cs AddConditions) Build(builder BuilderInterface) {
+	for idx, c := range cs {
+		if idx > 0 {
+			builder.Write(" AND ")
+		}
+		c.Build(builder)
+	}
+}
+
+type ORConditions []Interface
+
+func (cs ORConditions) Build(builder BuilderInterface) {
+	for idx, c := range cs {
+		if idx > 0 {
+			builder.Write(" OR ")
+		}
+		c.Build(builder)
+	}
+}
+
+type NotConditions []Interface
+
+func (cs NotConditions) Build(builder BuilderInterface) {
+	for idx, c := range cs {
+		if idx > 0 {
+			builder.Write(" AND ")
+		}
+
+		if negationBuilder, ok := c.(NegationBuilder); ok {
+			negationBuilder.NegationBuild(builder)
+		} else {
+			builder.Write(" NOT ")
+			c.Build(builder)
+		}
+	}
+}
+
+// Raw raw sql for where
+type Raw struct {
+	SQL    string
+	Values []interface{}
+}
+
+func (raw Raw) Build(builder BuilderInterface) {
+	sql := raw.SQL
+	for _, v := range raw.Values {
+		sql = strings.Replace(sql, " ? ", " "+builder.AddVar(v)+" ", 1)
+	}
+	builder.Write(sql)
+}
+
+// IN Whether a value is within a set of values
+type IN struct {
+	Column interface{}
+	Values []interface{}
+}
+
+func (in IN) Build(builder BuilderInterface) {
+	builder.WriteQuoted(in.Column)
+
+	if len(in.Values) == 0 {
+		builder.Write(" IN (NULL)")
+	} else {
+		builder.Write(" IN (", builder.AddVar(in.Values...), ")")
+	}
+}
+
+func (in IN) NegationBuild(builder BuilderInterface) {
+	if len(in.Values) != 0 {
+		builder.WriteQuoted(in.Column)
+		builder.Write(" NOT IN (", builder.AddVar(in.Values...), ")")
+	}
+}
+
+// Eq equal to for where
+type Eq struct {
+	Column interface{}
+	Value  interface{}
+}
+
+func (eq Eq) Build(builder BuilderInterface) {
+	builder.WriteQuoted(eq.Column)
+
+	if eq.Value == nil {
+		builder.Write(" IS NULL")
+	} else {
+		builder.Write(" = ", builder.AddVar(eq.Value))
+	}
+}
+
+func (eq Eq) NegationBuild(builder BuilderInterface) {
+	Neq{eq.Column, eq.Value}.Build(builder)
+}
+
+// Neq not equal to for where
+type Neq struct {
+	Column interface{}
+	Value  interface{}
+}
+
+func (neq Neq) Build(builder BuilderInterface) {
+	builder.WriteQuoted(neq.Column)
+
+	if neq.Value == nil {
+		builder.Write(" IS NOT NULL")
+	} else {
+		builder.Write(" <> ", builder.AddVar(neq.Value))
+	}
+}
+
+func (neq Neq) NegationBuild(builder BuilderInterface) {
+	Eq{neq.Column, neq.Value}.Build(builder)
+}
+
+// Gt greater than for where
+type Gt struct {
+	Column interface{}
+	Value  interface{}
+}
+
+func (gt Gt) Build(builder BuilderInterface) {
+	builder.WriteQuoted(gt.Column)
+	builder.Write(" > ", builder.AddVar(gt.Value))
+}
+
+func (gt Gt) NegationBuild(builder BuilderInterface) {
+	Lte{gt.Column, gt.Value}.Build(builder)
+}
+
+// Gte greater than or equal to for where
+type Gte struct {
+	Column interface{}
+	Value  interface{}
+}
+
+func (gte Gte) Build(builder BuilderInterface) {
+	builder.WriteQuoted(gte.Column)
+	builder.Write(" >= ", builder.AddVar(gte.Value))
+}
+
+func (gte Gte) NegationBuild(builder BuilderInterface) {
+	Lt{gte.Column, gte.Value}.Build(builder)
+}
+
+// Lt less than for where
+type Lt struct {
+	Column interface{}
+	Value  interface{}
+}
+
+func (lt Lt) Build(builder BuilderInterface) {
+	builder.WriteQuoted(lt.Column)
+	builder.Write(" < ", builder.AddVar(lt.Value))
+}
+
+func (lt Lt) NegationBuild(builder BuilderInterface) {
+	Gte{lt.Column, lt.Value}.Build(builder)
+}
+
+// Lte less than or equal to for where
+type Lte struct {
+	Column interface{}
+	Value  interface{}
+}
+
+func (lte Lte) Build(builder BuilderInterface) {
+	builder.WriteQuoted(lte.Column)
+	builder.Write(" <= ", builder.AddVar(lte.Value))
+}
+
+func (lte Lte) NegationBuild(builder BuilderInterface) {
+	Gt{lte.Column, lte.Value}.Build(builder)
+}
+
+// Like whether string matches regular expression
+type Like struct {
+	Column interface{}
+	Value  interface{}
+}
+
+func (like Like) Build(builder BuilderInterface) {
+	builder.WriteQuoted(like.Column)
+	builder.Write(" LIKE ", builder.AddVar(like.Value))
+}
+
+func (like Like) NegationBuild(builder BuilderInterface) {
+	builder.WriteQuoted(like.Column)
+	builder.Write(" NOT LIKE ", builder.AddVar(like.Value))
+}
diff --git a/finisher_api.go b/finisher_api.go
new file mode 100644
index 00000000..687843e3
--- /dev/null
+++ b/finisher_api.go
@@ -0,0 +1,154 @@
+package gorm
+
+import (
+	"database/sql"
+)
+
+func (db *DB) Count(sql string, values ...interface{}) (tx *DB) {
+	tx = db.getInstance()
+	return
+}
+
+// First find first record that match given conditions, order by primary key
+func (db *DB) First(out interface{}, where ...interface{}) (tx *DB) {
+	tx = db.getInstance()
+	return
+}
+
+// Take return a record that match given conditions, the order will depend on the database implementation
+func (db *DB) Take(out interface{}, where ...interface{}) (tx *DB) {
+	tx = db.getInstance()
+	return
+}
+
+// Last find last record that match given conditions, order by primary key
+func (db *DB) Last(out interface{}, where ...interface{}) (tx *DB) {
+	tx = db.getInstance()
+	return
+}
+
+// Find find records that match given conditions
+func (db *DB) Find(out interface{}, where ...interface{}) (tx *DB) {
+	tx = db.getInstance()
+	return
+}
+
+// Scan scan value to a struct
+
+func (db *DB) Row() *sql.Row {
+	// TODO
+	return nil
+}
+
+func (db *DB) Rows() (*sql.Rows, error) {
+	// TODO
+	return nil, nil
+}
+
+func (db *DB) Scan(dest interface{}) (tx *DB) {
+	tx = db.getInstance()
+	return
+}
+
+func (db *DB) ScanRows(rows *sql.Rows, result interface{}) error {
+	return nil
+}
+
+// Create insert the value into database
+func (db *DB) Create(value interface{}) (tx *DB) {
+	tx = db.getInstance()
+	return
+}
+
+// Save update value in database, if the value doesn't have primary key, will insert it
+func (db *DB) Save(value interface{}) (tx *DB) {
+	tx = db.getInstance()
+	return
+}
+
+// Update update attributes with callbacks, refer: https://jinzhu.github.io/gorm/crud.html#update
+func (db *DB) Update(column string, value interface{}) (tx *DB) {
+	tx = db.getInstance()
+	return
+}
+
+// Updates update attributes with callbacks, refer: https://jinzhu.github.io/gorm/crud.html#update
+func (db *DB) Updates(values interface{}) (tx *DB) {
+	tx = db.getInstance()
+	return
+}
+
+func (db *DB) UpdateColumn(attrs ...interface{}) (tx *DB) {
+	tx = db.getInstance()
+	return
+}
+
+func (db *DB) UpdateColumns(values interface{}) (tx *DB) {
+	tx = db.getInstance()
+	return
+}
+
+func (db *DB) FirstOrCreate(out interface{}, where ...interface{}) (tx *DB) {
+	tx = db.getInstance()
+	return
+}
+
+func (db *DB) FirstOrInit(out interface{}, where ...interface{}) (tx *DB) {
+	tx = db.getInstance()
+	return
+}
+
+// Delete delete value match given conditions, if the value has primary key, then will including the primary key as condition
+func (db *DB) Delete(value interface{}, where ...interface{}) (tx *DB) {
+	tx = db.getInstance()
+	return
+}
+
+func (db *DB) Related(value interface{}, foreignKeys ...string) (tx *DB) {
+	tx = db.getInstance()
+	return
+}
+
+func (db *DB) Transaction(fc func(tx *DB) error, opts ...*sql.TxOptions) (err error) {
+	panicked := true
+	tx := db.Begin(opts...)
+	defer func() {
+		// Make sure to rollback when panic, Block error or Commit error
+		if panicked || err != nil {
+			tx.Rollback()
+		}
+	}()
+
+	err = fc(tx)
+
+	if err == nil {
+		err = tx.Commit().Error
+	}
+
+	panicked = false
+	return
+}
+
+func (db *DB) Begin(opts ...*sql.TxOptions) (tx *DB) {
+	tx = db.getInstance()
+	return
+}
+
+func (db *DB) Commit() (tx *DB) {
+	tx = db.getInstance()
+	return
+}
+
+func (db *DB) Rollback() (tx *DB) {
+	tx = db.getInstance()
+	return
+}
+
+func (db *DB) Exec(sql string, values ...interface{}) (tx *DB) {
+	tx = db.getInstance()
+	return
+}
+
+func (db *DB) Association(column string) *Association {
+	return nil
+}
diff --git a/gorm.go b/gorm.go
index 274f4c62..1b6d88df 100644
--- a/gorm.go
+++ b/gorm.go
@@ -1,8 +1,10 @@
 package gorm
 
 import (
+	"context"
 	"time"
 
+	"github.com/jinzhu/gorm/clause"
 	"github.com/jinzhu/gorm/logger"
 )
 
@@ -38,9 +40,69 @@ type Model struct {
 // Dialector GORM database dialector
 type Dialector interface {
 	Migrator() Migrator
+	BindVar(stmt Statement, v interface{}) string
+}
+
+// Result
+type Result struct {
+	Error        error
+	RowsAffected int64
+	Statement    *Statement
 }
 
 // DB GORM DB definition
 type DB struct {
 	*Config
+	Dialector
+	Result
+	Context context.Context
+}
+
+// WithContext change current instance db's context to ctx
+func (db *DB) WithContext(ctx context.Context) *DB {
+	tx := db.getInstance()
+	tx.Context = ctx
+	return tx
+}
+
+// Set store value with key into current db instance's context
+func (db *DB) Set(key string, value interface{}) *DB {
+	tx := db.getInstance()
+	tx.Statement.Settings.Store(key, value)
+	return tx
+}
+
+// Get get value with key from current db instance's context
+func (db *DB) Get(key string) (interface{}, bool) {
+	if db.Statement != nil {
+		return db.Statement.Settings.Load(key)
+	}
+	return nil, false
+}
+
+func (db *DB) Close() *DB {
+	// TODO
+	return db
+}
+
+func (db *DB) getInstance() *DB {
+	// db.Result.Statement == nil means root DB
+	if db.Result.Statement == nil {
+		return &DB{
+			Config:    db.Config,
+			Dialector: db.Dialector,
+			Context:   context.Background(),
+			Result: Result{
+				Statement: &Statement{DB: db, Clauses: map[string][]clause.Interface{}},
+			},
+		}
+	}
+
+	return db
+}
+
+// Debug start debug mode
+func (db *DB) Debug() (tx *DB) {
+	tx = db.getInstance()
+	return
 }
diff --git a/model/model.go b/model/model.go
new file mode 100644
index 00000000..316f3ab5
--- /dev/null
+++ b/model/model.go
@@ -0,0 +1,37 @@
+package model
+
+import (
+	"reflect"
+)
+
+type Model struct {
+	ModelType               reflect.Type
+	Table                   string
+	PrioritizedPrimaryField *Field
+	PrimaryFields           []*Field
+	Fields                  []*Field
+	FieldsByName            map[string]*Field
+	FieldsByDBName          map[string]*Field
+	Relationships           Relationships
+}
+
+type Field struct {
+	Name            string
+	DBName          string
+	DataType        reflect.Type
+	DBDataType      string
+	Tag             reflect.StructTag
+	TagSettings     map[string]string
+	PrimaryKey      bool
+	AutoIncrement   bool
+	Creatable       bool
+	Updatable       bool
+	Nullable        bool
+	Unique          bool
+	Precision       int
+	Size            int
+	HasDefaultValue bool
+	DefaultValue    string
+	StructField     reflect.StructField
+	Model           *Model
+}
diff --git a/model/relationship.go b/model/relationship.go
new file mode 100644
index 00000000..60b0751e
--- /dev/null
+++ b/model/relationship.go
@@ -0,0 +1,37 @@
+package model
+
+// RelationshipType relationship type
+type RelationshipType string
+
+const (
+	HasOneRel    RelationshipType = "has_one"      // HasOneRel has one relationship
+	HasManyRel   RelationshipType = "has_many"     // HasManyRel has many relationship
+	BelongsToRel RelationshipType = "belongs_to"   // BelongsToRel belongs to relationship
+	Many2ManyRel RelationshipType = "many_to_many" // Many2ManyRel many to many relationship
+)
+
+type Relationships struct {
+	HasOne    map[string]*Relationship
+	BelongsTo map[string]*Relationship
+	HasMany   map[string]*Relationship
+	Many2Many map[string]*Relationship
+}
+
+type Relationship struct {
+	Type                   RelationshipType
+	ForeignKeys            []*RelationField // self
+	AssociationForeignKeys []*RelationField // association
+	JoinTable              *JoinTable
+}
+
+type RelationField struct {
+	*Field
+	PolymorphicField *Field
+	PolymorphicValue string
+}
+
+type JoinTable struct {
+	Table                  string
+	ForeignKeys            []*RelationField
+	AssociationForeignKeys []*RelationField
+}
diff --git a/statement.go b/statement.go
new file mode 100644
index 00000000..21e95e11
--- /dev/null
+++ b/statement.go
@@ -0,0 +1,68 @@
+package gorm
+
+import (
+	"bytes"
+	"context"
+	"database/sql"
+	"fmt"
+	"strings"
+	"sync"
+
+	"github.com/jinzhu/gorm/clause"
+)
+
+// Statement statement
+type Statement struct {
+	Dest     interface{}
+	Table    interface{}
+	Clauses  map[string][]clause.Interface
+	Settings sync.Map
+	Context  context.Context
+	DB       *DB
+	StatementBuilder
+}
+
+// StatementBuilder statement builder
+type StatementBuilder struct {
+	SQL       bytes.Buffer
+	Vars      []interface{}
+	NamedVars []sql.NamedArg
+}
+
+// Write write string
+func (stmt Statement) Write(sql ...string) (err error) {
+	for _, s := range sql {
+		_, err = stmt.SQL.WriteString(s)
+	}
+	return
+}
+
+// WriteQuoted write quoted field
+func (stmt Statement) WriteQuoted(field interface{}) (err error) {
+	_, err = stmt.SQL.WriteString(stmt.Quote(field))
+	return
+}
+
+// Write write string
+func (stmt Statement) AddVar(vars ...interface{}) string {
+	var placeholders []string
+	for _, v := range vars {
+		if namedArg, ok := v.(sql.NamedArg); ok && len(namedArg.Name) > 0 {
+			stmt.NamedVars = append(stmt.NamedVars, namedArg)
+			placeholders = append(placeholders, "@"+namedArg.Name)
+		} else {
+			placeholders = append(placeholders, stmt.DB.Dialector.BindVar(stmt, v))
+		}
+	}
+	return strings.Join(placeholders, ",")
+}
+
+// Quote returns quoted value
+func (stmt Statement) Quote(field interface{}) (str string) {
+	return fmt.Sprint(field)
+}
+
+// AddClause add clause
+func (s Statement) AddClause(clause clause.Interface) {
+	s.Clauses[clause.Name()] = append(s.Clauses[clause.Name()], clause)
+}