Merge pull request #6 from coreybutler/master

Add field alias support.

README.md

@@ -34,6 +34,7 @@ query.Query {
 	Updates: map[]
 	Inserts: []
 	Fields: [a]
+	Aliases: map[]
 }
 ```
 
@@ -49,6 +50,7 @@ query.Query {
 	Updates: map[]
 	Inserts: []
 	Fields: [a]
+	Aliases: map[]
 }
 ```
 
@@ -64,6 +66,23 @@ query.Query {
 	Updates: map[]
 	Inserts: []
 	Fields: [a c d]
+	Aliases: map[]
+}
+```
+
+### Example: SELECT with alias works
+
+```
+query, err := sqlparser.Parse(`SELECT a as z, b as y, c FROM 'b'`)
+
+query.Query {
+	Type: Select
+	TableName: b
+	Conditions: []
+	Updates: map[]
+	Inserts: []
+	Fields: [a b c]
+	Aliases: map[a:z b:y]
 }
 ```
 
@@ -86,6 +105,7 @@ query.Query {
 	Updates: map[]
 	Inserts: []
 	Fields: [a c d]
+	Aliases: map[]
 }
 ```
 
@@ -108,6 +128,7 @@ query.Query {
 	Updates: map[]
 	Inserts: []
 	Fields: [a c d]
+	Aliases: map[]
 }
 ```
 
@@ -130,6 +151,7 @@ query.Query {
 	Updates: map[]
 	Inserts: []
 	Fields: [a c d]
+	Aliases: map[]
 }
 ```
 
@@ -152,6 +174,7 @@ query.Query {
 	Updates: map[]
 	Inserts: []
 	Fields: [a c d]
+	Aliases: map[]
 }
 ```
 
@@ -174,6 +197,7 @@ query.Query {
 	Updates: map[]
 	Inserts: []
 	Fields: [a c d]
+	Aliases: map[]
 }
 ```
 
@@ -196,6 +220,7 @@ query.Query {
 	Updates: map[]
 	Inserts: []
 	Fields: [a c d]
+	Aliases: map[]
 }
 ```
 
@@ -218,6 +243,7 @@ query.Query {
 	Updates: map[]
 	Inserts: []
 	Fields: [a c d]
+	Aliases: map[]
 }
 ```
 
@@ -233,6 +259,7 @@ query.Query {
 	Updates: map[]
 	Inserts: []
 	Fields: [*]
+	Aliases: map[]
 }
 ```
 
@@ -248,6 +275,7 @@ query.Query {
 	Updates: map[]
 	Inserts: []
 	Fields: [a *]
+	Aliases: map[]
 }
 ```
 
@@ -277,6 +305,7 @@ query.Query {
 	Updates: map[]
 	Inserts: []
 	Fields: [a c d]
+	Aliases: map[]
 }
 ```
 
@@ -299,6 +328,7 @@ query.Query {
 	Updates: map[b:hello]
 	Inserts: []
 	Fields: []
+	Aliases: map[]
 }
 ```
 
@@ -321,6 +351,7 @@ query.Query {
 	Updates: map[b:hello\'world]
 	Inserts: []
 	Fields: []
+	Aliases: map[]
 }
 ```
 
@@ -343,6 +374,7 @@ query.Query {
 	Updates: map[b:hello c:bye]
 	Inserts: []
 	Fields: []
+	Aliases: map[]
 }
 ```
 
@@ -372,6 +404,7 @@ query.Query {
 	Updates: map[b:hello c:bye]
 	Inserts: []
 	Fields: []
+	Aliases: map[]
 }
 ```
 
@@ -394,6 +427,7 @@ query.Query {
 	Updates: map[]
 	Inserts: []
 	Fields: []
+	Aliases: map[]
 }
 ```
 
@@ -409,6 +443,7 @@ query.Query {
 	Updates: map[]
 	Inserts: [[1]]
 	Fields: [b]
+	Aliases: map[]
 }
 ```
 
@@ -424,6 +459,7 @@ query.Query {
 	Updates: map[]
 	Inserts: [[1 2 3]]
 	Fields: [b c d]
+	Aliases: map[]
 }
 ```
 
@@ -439,6 +475,7 @@ query.Query {
 	Updates: map[]
 	Inserts: [[1 2 3] [4 5 6]]
 	Fields: [b c d]
+	Aliases: map[]
 }
 ```
 

README.template

@@ -43,6 +43,7 @@ query.Query {
 	Updates: {{.Expected.Updates}}
 	Inserts: {{.Expected.Inserts}}
 	Fields: {{.Expected.Fields}}
+	Aliases: {{.Expected.Aliases}}
 }
 ```
 {{end}}

query/query.go

@@ -8,6 +8,7 @@ type Query struct {
 	Updates    map[string]string
 	Inserts    [][]string
 	Fields     []string // Used for SELECT (i.e. SELECTed field names) and INSERT (INSERTEDed field names)
+	Aliases    map[string]string
 }
 
 // Type is the type of SQL query, e.g. SELECT/UPDATE

sql.go

@@ -121,6 +121,19 @@ func (p *parser) doParse() (query.Query, error) {
 			p.query.Fields = append(p.query.Fields, identifier)
 			p.pop()
 			maybeFrom := p.peek()
+			if strings.ToUpper(maybeFrom) == "AS" {
+				p.pop()
+				alias := p.peek()
+				if !isIdentifier(alias) {
+					return p.query, fmt.Errorf("at SELECT: expected field alias for \"" + identifier + " as\" to SELECT")
+				}
+				if p.query.Aliases == nil {
+					p.query.Aliases = make(map[string]string)
+				}
+				p.query.Aliases[identifier] = alias
+				p.pop()
+				maybeFrom = p.peek()
+			}
 			if strings.ToUpper(maybeFrom) == "FROM" {
 				p.step = stepSelectFrom
 				continue
@@ -370,7 +383,7 @@ func (p *parser) popWhitespace() {
 
 var reservedWords = []string{
 	"(", ")", ">=", "<=", "!=", ",", "=", ">", "<", "SELECT", "INSERT INTO", "VALUES", "UPDATE", "DELETE FROM",
-	"WHERE", "FROM", "SET",
+	"WHERE", "FROM", "SET", "AS",
 }
 
 func (p *parser) peekWithLength() (string, int) {

sql_test.go

@@ -70,6 +70,21 @@ func TestSQL(t *testing.T) {
 			Expected: query.Query{Type: query.Select, TableName: "b", Fields: []string{"a", "c", "d"}},
 			Err:      nil,
 		},
+		{
+			Name: "SELECT with alias works",
+			SQL:  "SELECT a as z, b as y, c FROM 'b'",
+			Expected: query.Query{
+				Type:      query.Select,
+				TableName: "b",
+				Fields:    []string{"a", "b", "c"},
+				Aliases: map[string]string{
+					"a": "z",
+					"b": "y",
+				},
+			},
+			Err: nil,
+		},
+
 		{
 			Name:     "SELECT with empty WHERE fails",
 			SQL:      "SELECT a, c, d FROM 'b' WHERE",