From 0e605681b23b28c284df9f2b10426f48c071e6d7 Mon Sep 17 00:00:00 2001
From: Ariel Mashraki <mashraki@fb.com>
Date: Sun, 23 Jun 2019 01:48:26 -0700
Subject: [PATCH] quote table name on DESCRIBE statement (#7)

Summary:
Pull Request resolved: https://github.com/facebookincubator/ent/pull/7

avoid conflicting with reserved words (e.g. "groups" became reserved word in MySQL 8.x)

Reviewed By: alexsn

Differential Revision: D15957279

fbshipit-source-id: b6944752c7e5f6ec37119b11cc0ab8a0d7d3a7ff
---
 dialect/sql/builder.go           | 19 +++++++++++++++++++
 dialect/sql/builder_test.go      |  4 ++++
 dialect/sql/schema/mysql.go      |  3 ++-
 dialect/sql/schema/mysql_test.go |  4 ++--
 4 files changed, 27 insertions(+), 3 deletions(-)

diff --git a/dialect/sql/builder.go b/dialect/sql/builder.go
index b6296d384..1a13c8e8f 100644
--- a/dialect/sql/builder.go
+++ b/dialect/sql/builder.go
@@ -257,6 +257,25 @@ func (t *TableBuilder) Query() (string, []interface{}) {
 	return t.b.String(), t.b.args
 }
 
+// DescribeBuilder is a query builder for `DESCRIBE` statement.
+type DescribeBuilder struct {
+	b    Builder
+	name string // table name.
+}
+
+// Describe returns a query builder for the `DESCRIBE` statement.
+//
+//	Describe("users")
+//
+func Describe(name string) *DescribeBuilder { return &DescribeBuilder{b: Builder{}, name: name} }
+
+// Query returns query representation of a `DESCRIBE` statement.
+func (t *DescribeBuilder) Query() (string, []interface{}) {
+	t.b.WriteString("DESCRIBE ")
+	t.b.Append(t.name)
+	return t.b.String(), nil
+}
+
 // TableAlter is a query builder for `ALTER TABLE` statement.
 type TableAlter struct {
 	b     Builder
diff --git a/dialect/sql/builder_test.go b/dialect/sql/builder_test.go
index ef02be266..a5b100e99 100644
--- a/dialect/sql/builder_test.go
+++ b/dialect/sql/builder_test.go
@@ -13,6 +13,10 @@ func TestBuilder(t *testing.T) {
 		wantQuery string
 		wantArgs  []interface{}
 	}{
+		{
+			input:     Describe("users"),
+			wantQuery: "DESCRIBE `users`",
+		},
 		{
 			input: CreateTable("users").
 				Columns(
diff --git a/dialect/sql/schema/mysql.go b/dialect/sql/schema/mysql.go
index 3021fbf8b..58f65223b 100644
--- a/dialect/sql/schema/mysql.go
+++ b/dialect/sql/schema/mysql.go
@@ -131,7 +131,8 @@ func (d *MySQL) exist(ctx context.Context, tx dialect.Tx, query string, args ...
 // table loads the current table description from the database.
 func (d *MySQL) table(ctx context.Context, tx dialect.Tx, name string) (*Table, error) {
 	rows := &sql.Rows{}
-	if err := tx.Query(ctx, "DESCRIBE "+name, []interface{}{}, rows); err != nil {
+	query, args := sql.Describe(name).Query()
+	if err := tx.Query(ctx, query, args, rows); err != nil {
 		return nil, fmt.Errorf("dialect/mysql: reading table description %v", err)
 	}
 	defer rows.Close()
diff --git a/dialect/sql/schema/mysql_test.go b/dialect/sql/schema/mysql_test.go
index 802cf20a2..d6e64368f 100644
--- a/dialect/sql/schema/mysql_test.go
+++ b/dialect/sql/schema/mysql_test.go
@@ -151,7 +151,7 @@ func TestMySQL_Create(t *testing.T) {
 						AND TABLE_NAME = ?`)).
 					WithArgs("users").
 					WillReturnRows(sqlmock.NewRows([]string{"count"}).AddRow(1))
-				mock.ExpectQuery("DESCRIBE users").
+				mock.ExpectQuery("DESCRIBE `users`").
 					WillReturnRows(sqlmock.NewRows([]string{"Field", "Type", "Null", "Key", "Default", "Extra"}).
 						AddRow("id", "int(11)", "NO", "PRI", "NULL", "auto_increment").
 						AddRow("name", "varchar(255)", "NO", "YES", "NULL", ""))
@@ -194,7 +194,7 @@ func TestMySQL_Create(t *testing.T) {
 						AND TABLE_NAME = ?`)).
 					WithArgs("users").
 					WillReturnRows(sqlmock.NewRows([]string{"count"}).AddRow(1))
-				mock.ExpectQuery("DESCRIBE users").
+				mock.ExpectQuery("DESCRIBE `users`").
 					WillReturnRows(sqlmock.NewRows([]string{"Field", "Type", "Null", "Key", "Default", "Extra"}).
 						AddRow("id", "int(11)", "NO", "PRI", "NULL", "auto_increment").
 						AddRow("name", "varchar(255)", "NO", "YES", "NULL", ""))