Merge pull request #338 from pingcap/siddontang/update-as

parser: update as option

parser/parser.y

@@ -465,6 +465,7 @@ import (
 	SubSelect		"Sub Select"
 	Symbol			"Constraint Symbol"
 	SystemVariable		"System defined variable name"
+	TableAsOpt		"table as option"
 	TableConstraint		"table constraint definition"
 	TableElement		"table definition element"
 	TableElementList	"table definition element list"
@@ -1537,15 +1538,22 @@ Field1:
 	}
 
 AsOpt:
-	identifier
+	Identifier
 	{
-		// TODO: check potential bug
 		$$ = $1
 	}
 |	"AS" Identifier
 	{
 		$$ = $2
 	}
+|	stringLit
+	{
+		$$ = $1
+	}
+|	"AS" stringLit
+	{
+		$$ = $2
+	}
 
 FieldList:
 	Field
@@ -2927,11 +2935,11 @@ TableFactor:
 	{
 		$$ = &rsets.TableSource{Source: $1, Name: $2.(string)}
 	}
-|	'(' SelectStmt ')' AsOpt
+|	'(' SelectStmt ')' TableAsOpt
 	{
 		$$ = &rsets.TableSource{Source: $2, Name: $4.(string)}
 	}
-|	'(' UnionStmt ')' AsOpt
+|	'(' UnionStmt ')' TableAsOpt
 	{
 		$$ = &rsets.TableSource{Source: $2, Name: $4.(string)}
 	}
@@ -2944,11 +2952,20 @@ TableIdentOpt:
 	{
 		$$ = ""
 	}
-|	AsOpt 
+|	TableAsOpt 
 	{
 		$$ = $1
 	}
 
+TableAsOpt:
+	Identifier
+	{
+		$$ = $1
+	}
+|	"AS" Identifier
+	{
+		$$ = $2
+	}
 
 JoinTable:
 	/* Use %prec to evaluate production TableRef before cross join */

parser/parser_test.go

@@ -499,6 +499,16 @@ func (s *testParserSuite) TestParser0(c *C) {
 
 		// For check clause
 		{"CREATE TABLE Customer (SD integer CHECK (SD > 0), First_Name varchar(30));", true},
+
+		// For as
+		{"select 1 as a, 1 as `a`, 1 as \"a\", 1 as 'a'", true},
+		{`select 1 as a, 1 as "a", 1 as 'a'`, true},
+		{`select 1 a, 1 "a", 1 'a'`, true},
+		{`select * from t as "a"`, false},
+		{`select * from t a`, true},
+		{`select * from t as a`, true},
+		{"select 1 full, 1 row, 1 abs", true},
+		{"select * from t full, t1 row, t2 abs", true},
 	}
 
 	for _, t := range table {