Fix issue 3966, get_format(TIMESTAMP, 'USA') (#3976)

expression/builtin_time.go

@@ -34,9 +34,10 @@ import (
 )
 
 const ( // GET_FORMAT first argument.
-	dateFormat     = "DATE"
-	datetimeFormat = "DATETIME"
-	timeFormat     = "TIME"
+	dateFormat      = "DATE"
+	datetimeFormat  = "DATETIME"
+	timestampFormat = "TIMESTAMP"
+	timeFormat      = "TIME"
 )
 
 const ( // GET_FORMAT location.
@@ -1129,7 +1130,7 @@ func (b *builtinGetFormatSig) eval(row []types.Datum) (d types.Datum, err error)
 		case internalLocation:
 			d.SetString("%Y%m%d")
 		}
-	case datetimeFormat:
+	case datetimeFormat, timestampFormat:
 		switch l {
 		case usaLocation:
 			d.SetString("%Y-%m-%d %H.%i.%s")

parser/parser.y

@@ -862,7 +862,7 @@ import (
 	logAnd			"logical and operator"
 	logOr			"logical or operator"
 	FieldsOrColumns 	"Fields or columns"
-	GetFormatSelector	"{DATE|DATETIME|TIME}"
+	GetFormatSelector	"{DATE|DATETIME|TIME|TIMESTAMP}"
 
 %type	<ident>
 	Identifier			"identifier or unreserved keyword"
@@ -3826,6 +3826,10 @@ GetFormatSelector:
 	{
 		$$ = strings.ToUpper($1)
 	}
+|	"TIMESTAMP"
+	{
+		$$ = strings.ToUpper($1)
+	}
 
 
 FunctionNameDateArith:

parser/parser_test.go

@@ -752,6 +752,7 @@ func (s *testParserSuite) TestBuiltin(c *C) {
 		{"SELECT GET_FORMAT(DATE, 'USA');", true},
 		{"SELECT GET_FORMAT(DATETIME, 'USA');", true},
 		{"SELECT GET_FORMAT(TIME, 'USA');", true},
+		{"SELECT GET_FORMAT(TIMESTAMP, 'USA');", true},
 
 		// for LOCALTIME, LOCALTIMESTAMP
 		{"SELECT LOCALTIME(), LOCALTIME(1)", true},