From c1afe197289c4abb99f440af7ad003d6d6224f24 Mon Sep 17 00:00:00 2001
From: Jinzhu <wosmvp@gmail.com>
Date: Fri, 14 Feb 2020 00:09:44 +0800
Subject: [PATCH] Add benchmark tests for clause

---
 clause/benchmarks_test.go | 56 +++++++++++++++++++++++++++++++++++++++
 clause/where.go           | 12 ++++-----
 statement.go              |  6 ++---
 3 files changed, 65 insertions(+), 9 deletions(-)
 create mode 100644 clause/benchmarks_test.go

diff --git a/clause/benchmarks_test.go b/clause/benchmarks_test.go
new file mode 100644
index 00000000..33d3430a
--- /dev/null
+++ b/clause/benchmarks_test.go
@@ -0,0 +1,56 @@
+package clause_test
+
+import (
+	"sync"
+	"testing"
+
+	"github.com/jinzhu/gorm"
+	"github.com/jinzhu/gorm/clause"
+	"github.com/jinzhu/gorm/schema"
+	"github.com/jinzhu/gorm/tests"
+)
+
+func BenchmarkSelect(b *testing.B) {
+	user, _ := schema.Parse(&tests.User{}, &sync.Map{}, db.NamingStrategy)
+
+	for i := 0; i < b.N; i++ {
+		stmt := gorm.Statement{DB: db, Table: user.Table, Schema: user, Clauses: map[string]clause.Clause{}}
+		clauses := []clause.Interface{clause.Select{}, clause.From{}, clause.Where{Exprs: []clause.Expression{clause.Eq{Column: clause.PrimaryColumn, Value: "1"}, clause.Gt{Column: "age", Value: 18}, clause.Or(clause.Neq{Column: "name", Value: "jinzhu"})}}}
+
+		for _, clause := range clauses {
+			stmt.AddClause(clause)
+		}
+
+		stmt.Build("SELECT", "FROM", "WHERE")
+		_ = stmt.SQL.String()
+	}
+}
+
+func BenchmarkComplexSelect(b *testing.B) {
+	user, _ := schema.Parse(&tests.User{}, &sync.Map{}, db.NamingStrategy)
+
+	for i := 0; i < b.N; i++ {
+		stmt := gorm.Statement{DB: db, Table: user.Table, Schema: user, Clauses: map[string]clause.Clause{}}
+		clauses := []clause.Interface{
+			clause.Select{}, clause.From{},
+			clause.Where{Exprs: []clause.Expression{
+				clause.Eq{Column: clause.PrimaryColumn, Value: "1"},
+				clause.Gt{Column: "age", Value: 18},
+				clause.Or(clause.Neq{Column: "name", Value: "jinzhu"}),
+			}},
+			clause.Where{Exprs: []clause.Expression{
+				clause.Or(clause.Gt{Column: "score", Value: 100}, clause.Like{Column: "name", Value: "%linus%"}),
+			}},
+			clause.GroupBy{Columns: []clause.Column{{Name: "role"}}, Having: clause.Where{[]clause.Expression{clause.Eq{"role", "admin"}}}},
+			clause.Limit{Limit: 10, Offset: 20},
+			clause.OrderBy{Columns: []clause.OrderByColumn{{Column: clause.PrimaryColumn, Desc: true}}},
+		}
+
+		for _, clause := range clauses {
+			stmt.AddClause(clause)
+		}
+
+		stmt.Build("SELECT", "FROM", "WHERE", "GROUP BY", "LIMIT", "ORDER BY")
+		_ = stmt.SQL.String()
+	}
+}
diff --git a/clause/where.go b/clause/where.go
index d0f57ed1..0ee1a141 100644
--- a/clause/where.go
+++ b/clause/where.go
@@ -61,7 +61,7 @@ type AndConditions struct {
 
 func (and AndConditions) Build(builder Builder) {
 	if len(and.Exprs) > 1 {
-		builder.Write("(")
+		builder.WriteByte('(')
 	}
 	for idx, c := range and.Exprs {
 		if idx > 0 {
@@ -70,7 +70,7 @@ func (and AndConditions) Build(builder Builder) {
 		c.Build(builder)
 	}
 	if len(and.Exprs) > 1 {
-		builder.Write(")")
+		builder.WriteByte(')')
 	}
 }
 
@@ -87,7 +87,7 @@ type OrConditions struct {
 
 func (or OrConditions) Build(builder Builder) {
 	if len(or.Exprs) > 1 {
-		builder.Write("(")
+		builder.WriteByte('(')
 	}
 	for idx, c := range or.Exprs {
 		if idx > 0 {
@@ -96,7 +96,7 @@ func (or OrConditions) Build(builder Builder) {
 		c.Build(builder)
 	}
 	if len(or.Exprs) > 1 {
-		builder.Write(")")
+		builder.WriteByte(')')
 	}
 }
 
@@ -113,7 +113,7 @@ type NotConditions struct {
 
 func (not NotConditions) Build(builder Builder) {
 	if len(not.Exprs) > 1 {
-		builder.Write("(")
+		builder.WriteByte('(')
 	}
 	for idx, c := range not.Exprs {
 		if idx > 0 {
@@ -128,6 +128,6 @@ func (not NotConditions) Build(builder Builder) {
 		}
 	}
 	if len(not.Exprs) > 1 {
-		builder.Write(")")
+		builder.WriteByte(')')
 	}
 }
diff --git a/statement.go b/statement.go
index 5dd49623..1c3934c1 100644
--- a/statement.go
+++ b/statement.go
@@ -153,13 +153,13 @@ func (stmt *Statement) AddVar(vars ...interface{}) string {
 		case clause.Column:
 			placeholders.WriteString(stmt.Quote(v))
 		case []interface{}:
-			placeholders.WriteByte('(')
 			if len(v) > 0 {
+				placeholders.WriteByte('(')
 				placeholders.WriteString(stmt.AddVar(v...))
+				placeholders.WriteByte(')')
 			} else {
-				placeholders.WriteString("NULL")
+				placeholders.WriteString("(NULL)")
 			}
-			placeholders.WriteByte(')')
 		default:
 			stmt.Vars = append(stmt.Vars, v)
 			placeholders.WriteString(stmt.DB.Dialector.BindVar(stmt, v))