From 48223227185ce23d3712a973109d3d0a62ff1d4e Mon Sep 17 00:00:00 2001
From: lkk2003rty <superzhaob@gmail.com>
Date: Wed, 26 Apr 2017 22:07:49 +0800
Subject: [PATCH] add buildin function UTC_TIME (#3145)

---
 expression/builtin_time.go      | 16 +++++++++++++++-
 expression/builtin_time_test.go | 27 +++++++++++++++++++++++++++
 plan/typeinferer.go             |  2 +-
 plan/typeinferer_test.go        |  2 ++
 4 files changed, 45 insertions(+), 2 deletions(-)

diff --git a/expression/builtin_time.go b/expression/builtin_time.go
index 84c7f6ee8ad36..c099b65519dcf 100644
--- a/expression/builtin_time.go
+++ b/expression/builtin_time.go
@@ -2330,5 +2330,19 @@ type builtinUTCTimeSig struct {
 // eval evals a builtinUTCTimeSig.
 // See https://dev.mysql.com/doc/refman/5.7/en/date-and-time-functions.html#function_utc-time
 func (b *builtinUTCTimeSig) eval(row []types.Datum) (d types.Datum, err error) {
-	return d, errFunctionNotExists.GenByArgs("UTC_TIME")
+	const utctimeFormat = "15:04:05.000000"
+	args, err := b.evalArgs(row)
+	if err != nil {
+		return types.Datum{}, errors.Trace(err)
+	}
+	fsp := 0
+	sc := b.ctx.GetSessionVars().StmtCtx
+	if len(args) == 1 && !args[0].IsNull() {
+		if fsp, err = checkFsp(sc, args[0]); err != nil {
+			d.SetNull()
+			return d, errors.Trace(err)
+		}
+	}
+	d.SetString(time.Now().UTC().Format(utctimeFormat))
+	return convertToDuration(b.ctx.GetSessionVars().StmtCtx, d, fsp)
 }
diff --git a/expression/builtin_time_test.go b/expression/builtin_time_test.go
index e09cd5dc0f3a6..b0e99baa16804 100644
--- a/expression/builtin_time_test.go
+++ b/expression/builtin_time_test.go
@@ -611,6 +611,33 @@ func (s *testEvaluatorSuite) TestCurrentTime(c *C) {
 	c.Assert(err, NotNil)
 }
 
+func (s *testEvaluatorSuite) TestUTCTime(c *C) {
+	defer testleak.AfterTest(c)()
+
+	tfStr := "15:04:05"
+	last := time.Now().UTC()
+	fc := funcs[ast.UTCTime]
+
+	tests := []struct {
+		param  interface{}
+		expect int
+	}{{nil, 8}, {0, 8}, {3, 12}, {6, 15}, {-1, 0}, {7, 0}}
+
+	for _, test := range tests {
+		f, err := fc.getFunction(datumsToConstants(types.MakeDatums(test.param)), s.ctx)
+		c.Assert(err, IsNil)
+		v, err := f.eval(nil)
+		if test.expect > 0 {
+			c.Assert(err, IsNil)
+			n := v.GetMysqlDuration()
+			c.Assert(n.String(), HasLen, test.expect)
+			c.Assert(n.String(), GreaterEqual, last.Format(tfStr))
+		} else {
+			c.Assert(err, NotNil)
+		}
+	}
+}
+
 func (s *testEvaluatorSuite) TestUTCDate(c *C) {
 	defer testleak.AfterTest(c)()
 	last := time.Now().UTC()
diff --git a/plan/typeinferer.go b/plan/typeinferer.go
index ff4f3d357bf75..4937232e6d2a6 100644
--- a/plan/typeinferer.go
+++ b/plan/typeinferer.go
@@ -381,7 +381,7 @@ func (v *typeInferrer) handleFuncCallExpr(x *ast.FuncCallExpr) {
 		tp = types.NewFieldType(mysql.TypeLonglong)
 		tp.Flag |= mysql.UnsignedFlag
 	// time related
-	case ast.Curtime, ast.CurrentTime, ast.TimeDiff, ast.MakeTime, ast.SecToTime:
+	case ast.Curtime, ast.CurrentTime, ast.TimeDiff, ast.MakeTime, ast.SecToTime, ast.UTCTime:
 		tp = types.NewFieldType(mysql.TypeDuration)
 		tp.Decimal = v.getFsp(x)
 	case ast.Curdate, ast.CurrentDate, ast.Date, ast.FromDays, ast.MakeDate:
diff --git a/plan/typeinferer_test.go b/plan/typeinferer_test.go
index 7625d9bcdb7b9..2e948fbe0cbb9 100644
--- a/plan/typeinferer_test.go
+++ b/plan/typeinferer_test.go
@@ -158,6 +158,8 @@ func (ts *testTypeInferrerSuite) TestInferType(c *C) {
 		{"maketime(12, 15, 30)", mysql.TypeDuration, charset.CharsetBin, mysql.BinaryFlag},
 		{"sec_to_time(2378)", mysql.TypeDuration, charset.CharsetBin, mysql.BinaryFlag},
 		{"current_timestamp()", mysql.TypeDatetime, charset.CharsetBin, mysql.BinaryFlag},
+		{"utc_time()", mysql.TypeDuration, charset.CharsetBin, mysql.BinaryFlag},
+		{"utc_time(3)", mysql.TypeDuration, charset.CharsetBin, mysql.BinaryFlag},
 		{"utc_timestamp()", mysql.TypeDatetime, charset.CharsetBin, mysql.BinaryFlag},
 		{"microsecond('2009-12-31 23:59:59.000010')", mysql.TypeLonglong, charset.CharsetBin, mysql.BinaryFlag},
 		{"second('2009-12-31 23:59:59.000010')", mysql.TypeLonglong, charset.CharsetBin, mysql.BinaryFlag},