From b2ce51a06d99e42ac4b85622872631fe87609dfd Mon Sep 17 00:00:00 2001
From: Han Fei <hanfei19910905@gmail.com>
Date: Mon, 9 Jan 2017 23:25:22 +0800
Subject: [PATCH] *: support substr. (#2422)

---
 ast/functions.go          | 1 +
 expression/builtin.go     | 1 +
 plan/logical_plan_test.go | 4 ++++
 3 files changed, 6 insertions(+)

diff --git a/ast/functions.go b/ast/functions.go
index ecf30b695157d..62ec9e8cdc544 100644
--- a/ast/functions.go
+++ b/ast/functions.go
@@ -145,6 +145,7 @@ const (
 	Space          = "space"
 	Strcmp         = "strcmp"
 	Substring      = "substring"
+	Substr         = "substr"
 	SubstringIndex = "substring_index"
 	Trim           = "trim"
 	Upper          = "upper"
diff --git a/expression/builtin.go b/expression/builtin.go
index c91f01cf38a39..6832051713ba6 100644
--- a/expression/builtin.go
+++ b/expression/builtin.go
@@ -215,6 +215,7 @@ var Funcs = map[string]Func{
 	ast.Space:          {builtinSpace, 1, 1},
 	ast.Strcmp:         {builtinStrcmp, 2, 2},
 	ast.Substring:      {builtinSubstring, 2, 3},
+	ast.Substr:         {builtinSubstring, 2, 3},
 	ast.SubstringIndex: {builtinSubstringIndex, 3, 3},
 	ast.Trim:           {builtinTrim, 1, 3},
 	ast.Upper:          {builtinUpper, 1, 1},
diff --git a/plan/logical_plan_test.go b/plan/logical_plan_test.go
index 7cbc5a1c391f8..c87e0d43f7c6e 100644
--- a/plan/logical_plan_test.go
+++ b/plan/logical_plan_test.go
@@ -577,6 +577,10 @@ func (s *testPlanSuite) TestPlanBuilder(c *C) {
 			sql:  "do sleep(5)",
 			plan: "*plan.TableDual->Projection",
 		},
+		{
+			sql:  "select substr(\"abc\", 1)",
+			plan: "*plan.TableDual->Projection",
+		},
 	}
 	for _, ca := range cases {
 		comment := Commentf("for %s", ca.sql)