diff --git a/callbacks/create.go b/callbacks/create.go
index 028cdbc4..983b95ce 100644
--- a/callbacks/create.go
+++ b/callbacks/create.go
@@ -4,6 +4,7 @@ import (
 	"fmt"
 
 	"github.com/jinzhu/gorm"
+	"github.com/jinzhu/gorm/clause"
 )
 
 func BeforeCreate(db *gorm.DB) {
@@ -17,8 +18,14 @@ func SaveBeforeAssociations(db *gorm.DB) {
 }
 
 func Create(db *gorm.DB) {
-	db.Statement.Build("WITH", "INSERT", "VALUES", "ON_CONFLICT", "RETURNING")
-	db.DB.ExecContext(db.Context, db.Statement.SQL.String(), db.Statement.Vars...)
+	db.Statement.AddClauseIfNotExists(clause.Insert{
+		Table: clause.Table{Table: db.Statement.Table},
+	})
+
+	db.Statement.Build("INSERT", "VALUES", "ON_CONFLICT", "RETURNING")
+	result, err := db.DB.ExecContext(db.Context, db.Statement.SQL.String(), db.Statement.Vars...)
+	fmt.Println(err)
+	fmt.Println(result)
 	fmt.Println(db.Statement.SQL.String(), db.Statement.Vars)
 }
 
diff --git a/chainable_api.go b/chainable_api.go
index 95d5975c..b577d5cf 100644
--- a/chainable_api.go
+++ b/chainable_api.go
@@ -55,7 +55,9 @@ func (db *DB) Omit(columns ...string) (tx *DB) {
 
 func (db *DB) Where(query interface{}, args ...interface{}) (tx *DB) {
 	tx = db.getInstance()
-	tx.Statement.AddClause(clause.Where{AndConditions: tx.Statement.BuildCondtion(query, args...)})
+	tx.Statement.AddClause(clause.Where{
+		AndConditions: tx.Statement.BuildCondtion(query, args...),
+	})
 	return
 }
 
@@ -63,7 +65,9 @@ func (db *DB) Where(query interface{}, args ...interface{}) (tx *DB) {
 func (db *DB) Not(query interface{}, args ...interface{}) (tx *DB) {
 	tx = db.getInstance()
 	tx.Statement.AddClause(clause.Where{
-		AndConditions: []clause.Expression{clause.NotConditions(tx.Statement.BuildCondtion(query, args...))},
+		AndConditions: []clause.Expression{
+			clause.NotConditions(tx.Statement.BuildCondtion(query, args...)),
+		},
 	})
 	return
 }
@@ -72,7 +76,9 @@ func (db *DB) Not(query interface{}, args ...interface{}) (tx *DB) {
 func (db *DB) Or(query interface{}, args ...interface{}) (tx *DB) {
 	tx = db.getInstance()
 	tx.Statement.AddClause(clause.Where{
-		ORConditions: []clause.ORConditions{tx.Statement.BuildCondtion(query, args...)},
+		ORConditions: []clause.ORConditions{
+			tx.Statement.BuildCondtion(query, args...),
+		},
 	})
 	return
 }
diff --git a/clause/insert.go b/clause/insert.go
new file mode 100644
index 00000000..e056b35e
--- /dev/null
+++ b/clause/insert.go
@@ -0,0 +1,34 @@
+package clause
+
+type Insert struct {
+	Table    Table
+	Priority string
+}
+
+// Name insert clause name
+func (insert Insert) Name() string {
+	return "INSERT"
+}
+
+// Build build insert clause
+func (insert Insert) Build(builder Builder) {
+	if insert.Priority != "" {
+		builder.Write(insert.Priority)
+		builder.WriteByte(' ')
+	}
+
+	builder.Write("INTO ")
+	builder.WriteQuoted(insert.Table)
+}
+
+// MergeExpression merge insert clauses
+func (insert Insert) MergeExpression(expr Expression) {
+	if v, ok := expr.(Insert); ok {
+		if insert.Priority == "" {
+			insert.Priority = v.Priority
+		}
+		if insert.Table.Table == "" {
+			insert.Table = v.Table
+		}
+	}
+}
diff --git a/clause/value.go b/clause/value.go
new file mode 100644
index 00000000..4de0d91e
--- /dev/null
+++ b/clause/value.go
@@ -0,0 +1,39 @@
+package clause
+
+type Values struct {
+	Columns []Column
+	Values  [][]interface{}
+}
+
+// Name from clause name
+func (Values) Name() string {
+	return ""
+}
+
+// Build build from clause
+func (values Values) Build(builder Builder) {
+	if len(values.Columns) > 0 {
+		builder.WriteByte('(')
+		for idx, column := range values.Columns {
+			if idx > 0 {
+				builder.WriteByte(',')
+			}
+			builder.WriteQuoted(column)
+		}
+		builder.WriteByte(')')
+
+		builder.Write(" VALUES ")
+
+		for idx, value := range values.Values {
+			builder.WriteByte('(')
+			if idx > 0 {
+				builder.WriteByte(',')
+			}
+
+			builder.Write(builder.AddVar(value...))
+			builder.WriteByte(')')
+		}
+	} else {
+		builder.Write("DEFAULT VALUES")
+	}
+}
diff --git a/dialects/postgres/postgres.go b/dialects/postgres/postgres.go
new file mode 100644
index 00000000..3abf05e3
--- /dev/null
+++ b/dialects/postgres/postgres.go
@@ -0,0 +1,33 @@
+package postgres
+
+import (
+	"database/sql"
+
+	"github.com/jinzhu/gorm"
+	"github.com/jinzhu/gorm/callbacks"
+	_ "github.com/lib/pq"
+)
+
+type Dialector struct {
+	DSN string
+}
+
+func Open(dsn string) gorm.Dialector {
+	return &Dialector{DSN: dsn}
+}
+
+func (dialector Dialector) Initialize(db *gorm.DB) (err error) {
+	// register callbacks
+	callbacks.RegisterDefaultCallbacks(db)
+
+	db.DB, err = sql.Open("postgres", dialector.DSN)
+	return
+}
+
+func (Dialector) Migrator() gorm.Migrator {
+	return nil
+}
+
+func (Dialector) BindVar(stmt *gorm.Statement, v interface{}) string {
+	return "?"
+}
diff --git a/dialects/sqlite/sqlite.go b/dialects/sqlite/sqlite.go
index bcd6bd5c..91c3389e 100644
--- a/dialects/sqlite/sqlite.go
+++ b/dialects/sqlite/sqlite.go
@@ -1,29 +1,33 @@
 package sqlite
 
 import (
+	"database/sql"
+
 	"github.com/jinzhu/gorm"
 	"github.com/jinzhu/gorm/callbacks"
 	_ "github.com/mattn/go-sqlite3"
 )
 
 type Dialector struct {
+	DSN string
 }
 
 func Open(dsn string) gorm.Dialector {
-	return &Dialector{}
+	return &Dialector{DSN: dsn}
 }
 
-func (Dialector) Initialize(db *gorm.DB) error {
+func (dialector Dialector) Initialize(db *gorm.DB) (err error) {
 	// register callbacks
 	callbacks.RegisterDefaultCallbacks(db)
 
-	return nil
+	db.DB, err = sql.Open("sqlite3", dialector.DSN)
+	return
 }
 
 func (Dialector) Migrator() gorm.Migrator {
 	return nil
 }
 
-func (Dialector) BindVar(stmt gorm.Statement, v interface{}) string {
+func (Dialector) BindVar(stmt *gorm.Statement, v interface{}) string {
 	return "?"
 }
diff --git a/finisher_api.go b/finisher_api.go
index c79915d2..a311ca78 100644
--- a/finisher_api.go
+++ b/finisher_api.go
@@ -4,7 +4,16 @@ import (
 	"database/sql"
 )
 
-func (db *DB) Count(sql string, values ...interface{}) (tx *DB) {
+// Create insert the value into database
+func (db *DB) Create(value interface{}) (tx *DB) {
+	tx = db.getInstance()
+	tx.Statement.Dest = value
+	tx.callbacks.Create().Execute(tx)
+	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
 }
@@ -36,32 +45,12 @@ func (db *DB) Find(out interface{}, where ...interface{}) (tx *DB) {
 	return
 }
 
-func (db *DB) Row() *sql.Row {
-	return nil
-}
-
-func (db *DB) Rows() (*sql.Rows, error) {
-	return nil, nil
-}
-
-// Scan scan value to a struct
-func (db *DB) Scan(dest interface{}) (tx *DB) {
+func (db *DB) FirstOrInit(out interface{}, where ...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) {
+func (db *DB) FirstOrCreate(out interface{}, where ...interface{}) (tx *DB) {
 	tx = db.getInstance()
 	return
 }
@@ -78,7 +67,7 @@ func (db *DB) Updates(values interface{}) (tx *DB) {
 	return
 }
 
-func (db *DB) UpdateColumn(attrs ...interface{}) (tx *DB) {
+func (db *DB) UpdateColumn(column string, value interface{}) (tx *DB) {
 	tx = db.getInstance()
 	return
 }
@@ -88,16 +77,6 @@ func (db *DB) UpdateColumns(values interface{}) (tx *DB) {
 	return
 }
 
-func (db *DB) FirstOrInit(out interface{}, where ...interface{}) (tx *DB) {
-	tx = db.getInstance()
-	return
-}
-
-func (db *DB) FirstOrCreate(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()
@@ -119,6 +98,29 @@ func (db *DB) Association(column string) *Association {
 	return nil
 }
 
+func (db *DB) Count(value interface{}) (tx *DB) {
+	tx = db.getInstance()
+	return
+}
+
+func (db *DB) Row() *sql.Row {
+	return nil
+}
+
+func (db *DB) Rows() (*sql.Rows, error) {
+	return nil, nil
+}
+
+// Scan scan value to a struct
+func (db *DB) Scan(dest interface{}) (tx *DB) {
+	tx = db.getInstance()
+	return
+}
+
+func (db *DB) ScanRows(rows *sql.Rows, result interface{}) error {
+	return nil
+}
+
 func (db *DB) Transaction(fc func(tx *DB) error, opts ...*sql.TxOptions) (err error) {
 	panicked := true
 	tx := db.Begin(opts...)
diff --git a/go.mod b/go.mod
index 516a9759..1f4d31a2 100644
--- a/go.mod
+++ b/go.mod
@@ -2,4 +2,8 @@ module github.com/jinzhu/gorm
 
 go 1.13
 
-require github.com/jinzhu/inflection v1.0.0
+require (
+	github.com/jinzhu/inflection v1.0.0
+	github.com/lib/pq v1.3.0
+	github.com/mattn/go-sqlite3 v2.0.3+incompatible
+)
diff --git a/gorm.go b/gorm.go
index 8ac7e057..a72314bd 100644
--- a/gorm.go
+++ b/gorm.go
@@ -28,10 +28,11 @@ type DB struct {
 	*Config
 	Dialector
 	Instance
-	DB         CommonDB
-	clone      bool
-	callbacks  *callbacks
-	cacheStore *sync.Map
+	DB             CommonDB
+	ClauseBuilders map[string]clause.ClauseBuilder
+	clone          bool
+	callbacks      *callbacks
+	cacheStore     *sync.Map
 }
 
 // Session session config when create session with Session() method
@@ -140,11 +141,12 @@ func (db *DB) getInstance() *DB {
 				Context:   ctx,
 				Statement: &Statement{DB: db, Clauses: map[string]clause.Clause{}},
 			},
-			Config:     db.Config,
-			Dialector:  db.Dialector,
-			DB:         db.DB,
-			callbacks:  db.callbacks,
-			cacheStore: db.cacheStore,
+			Config:         db.Config,
+			Dialector:      db.Dialector,
+			ClauseBuilders: db.ClauseBuilders,
+			DB:             db.DB,
+			callbacks:      db.callbacks,
+			cacheStore:     db.cacheStore,
 		}
 	}
 
diff --git a/interfaces.go b/interfaces.go
index 98d04592..6ba24dc4 100644
--- a/interfaces.go
+++ b/interfaces.go
@@ -9,7 +9,7 @@ import (
 type Dialector interface {
 	Initialize(*DB) error
 	Migrator() Migrator
-	BindVar(stmt Statement, v interface{}) string
+	BindVar(stmt *Statement, v interface{}) string
 }
 
 // CommonDB common db interface
diff --git a/statement.go b/statement.go
index 4d959cbb..c01be0f5 100644
--- a/statement.go
+++ b/statement.go
@@ -5,6 +5,7 @@ import (
 	"database/sql"
 	"database/sql/driver"
 	"fmt"
+	"log"
 	"strconv"
 	"strings"
 	"sync"
@@ -21,7 +22,7 @@ type Instance struct {
 	Statement    *Statement
 }
 
-func (instance Instance) ToSQL(clauses ...string) (string, []interface{}) {
+func (instance *Instance) ToSQL(clauses ...string) (string, []interface{}) {
 	if len(clauses) > 0 {
 		instance.Statement.Build(clauses...)
 	}
@@ -29,7 +30,7 @@ func (instance Instance) ToSQL(clauses ...string) (string, []interface{}) {
 }
 
 // AddError add error to instance
-func (inst Instance) AddError(err error) {
+func (inst *Instance) AddError(err error) {
 	if inst.Error == nil {
 		inst.Error = err
 	} else {
@@ -55,11 +56,11 @@ type Statement struct {
 
 // StatementOptimizer statement optimizer interface
 type StatementOptimizer interface {
-	OptimizeStatement(Statement)
+	OptimizeStatement(*Statement)
 }
 
 // Write write string
-func (stmt Statement) Write(sql ...string) (err error) {
+func (stmt *Statement) Write(sql ...string) (err error) {
 	for _, s := range sql {
 		_, err = stmt.SQL.WriteString(s)
 	}
@@ -67,12 +68,12 @@ func (stmt Statement) Write(sql ...string) (err error) {
 }
 
 // Write write string
-func (stmt Statement) WriteByte(c byte) (err error) {
+func (stmt *Statement) WriteByte(c byte) (err error) {
 	return stmt.SQL.WriteByte(c)
 }
 
 // WriteQuoted write quoted field
-func (stmt Statement) WriteQuoted(field interface{}) (err error) {
+func (stmt *Statement) WriteQuoted(field interface{}) (err error) {
 	_, err = stmt.SQL.WriteString(stmt.Quote(field))
 	return
 }
@@ -107,7 +108,7 @@ func (stmt Statement) Quote(field interface{}) string {
 }
 
 // Write write string
-func (stmt Statement) AddVar(vars ...interface{}) string {
+func (stmt *Statement) AddVar(vars ...interface{}) string {
 	var placeholders strings.Builder
 	for idx, v := range vars {
 		if idx > 0 {
@@ -134,7 +135,7 @@ func (stmt Statement) AddVar(vars ...interface{}) string {
 }
 
 // AddClause add clause
-func (stmt Statement) AddClause(v clause.Interface) {
+func (stmt *Statement) AddClause(v clause.Interface) {
 	if optimizer, ok := v.(StatementOptimizer); ok {
 		optimizer.OptimizeStatement(stmt)
 	}
@@ -154,6 +155,30 @@ func (stmt Statement) AddClause(v clause.Interface) {
 	stmt.Clauses[v.Name()] = c
 }
 
+// AddClauseIfNotExists add clause if not exists
+func (stmt *Statement) AddClauseIfNotExists(v clause.Interface) {
+	if optimizer, ok := v.(StatementOptimizer); ok {
+		optimizer.OptimizeStatement(stmt)
+	}
+
+	log.Println(v.Name())
+	if c, ok := stmt.Clauses[v.Name()]; !ok {
+		if namer, ok := v.(clause.OverrideNameInterface); ok {
+			c.Name = namer.OverrideName()
+		} else {
+			c.Name = v.Name()
+		}
+
+		if c.Expression != nil {
+			v.MergeExpression(c.Expression)
+		}
+
+		c.Expression = v
+		stmt.Clauses[v.Name()] = c
+		log.Println(stmt.Clauses[v.Name()])
+	}
+}
+
 // BuildCondtion build condition
 func (stmt Statement) BuildCondtion(query interface{}, args ...interface{}) (conditions []clause.Expression) {
 	if sql, ok := query.(string); ok {
@@ -211,7 +236,7 @@ func (stmt Statement) BuildCondtion(query interface{}, args ...interface{}) (con
 }
 
 // Build build sql with clauses names
-func (stmt Statement) Build(clauses ...string) {
+func (stmt *Statement) Build(clauses ...string) {
 	var firstClauseWritten bool
 
 	for _, name := range clauses {
@@ -221,7 +246,11 @@ func (stmt Statement) Build(clauses ...string) {
 			}
 
 			firstClauseWritten = true
-			c.Build(stmt)
+			if b, ok := stmt.DB.ClauseBuilders[name]; ok {
+				b.Build(c, stmt)
+			} else {
+				c.Build(stmt)
+			}
 		}
 	}
 	// TODO handle named vars