Added ANSI_QUOTES mode

Author: sananguliyev

README.md

@@ -68,6 +68,34 @@ func main() {
 }
 ```
 
+Parsing SQL mode `ANSI_QUOTES`:
+
+Treat `"` as an identifier quote character (like the \` quote character) and not as a string quote character. You can still use \` to quote identifiers with this mode enabled. With `ANSI_QUOTES` enabled, you cannot use double quotation marks to quote literal strings because they are interpreted as identifiers.
+
+```go
+package main
+
+import (
+    "github.com/SananGuliyev/sqlparser"
+)
+
+func main() {
+    sql := "SELECT * FROM table WHERE a = 'abc'"
+    sqlparser.SQLMode = sqlparser.SQLModeANSIQuotes
+    stmt, err := sqlparser.Parse(sql)
+    if err != nil {
+    	// Do something with the err
+    }
+    
+    // Otherwise do something with stmt
+    switch stmt := stmt.(type) {
+    case *sqlparser.Select:
+    	_ = stmt
+    case *sqlparser.Insert:
+    }
+}
+```
+
 See [parse_test.go](https://github.com/SananGuliyev/sqlparser/blob/master/parse_test.go) for more examples, or read the [godoc](https://godoc.org/github.com/SananGuliyev/sqlparser).
 
 

analyzer.go

@@ -300,7 +300,7 @@ func ExtractSetValues(sql string) (keyValues map[SetKey]interface{}, scope strin
 			if setStmt.Scope != "" && scope != "" {
 				return nil, "", fmt.Errorf("unsupported in set: mixed using of variable scope")
 			}
-			_, out := NewStringTokenizer(key).Scan()
+			_, out := NewStringTokenizer(key, SQLMode).Scan()
 			key = string(out)
 		}
 

ast.go

@@ -29,6 +29,13 @@ import (
 	"github.com/SananGuliyev/sqlparser/dependency/sqltypes"
 )
 
+const (
+	SQLModeStandard = iota
+	SQLModeANSIQuotes
+)
+
+var SQLMode = SQLModeStandard
+
 // Instructions for creating new types: If a type
 // needs to satisfy an interface, declare that function
 // along with that interface. This will help users
@@ -46,7 +53,7 @@ import (
 // is partially parsed but still contains a syntax error, the
 // error is ignored and the DDL is returned anyway.
 func Parse(sql string) (Statement, error) {
-	tokenizer := NewStringTokenizer(sql)
+	tokenizer := NewStringTokenizer(sql, SQLMode)
 	if yyParse(tokenizer) != 0 {
 		if tokenizer.partialDDL != nil {
 			log.Printf("ignoring error parsing DDL '%s': %v", sql, tokenizer.LastError)
@@ -61,7 +68,7 @@ func Parse(sql string) (Statement, error) {
 // ParseStrictDDL is the same as Parse except it errors on
 // partially parsed DDL statements.
 func ParseStrictDDL(sql string) (Statement, error) {
-	tokenizer := NewStringTokenizer(sql)
+	tokenizer := NewStringTokenizer(sql, SQLMode)
 	if yyParse(tokenizer) != 0 {
 		return nil, tokenizer.LastError
 	}
@@ -97,7 +104,7 @@ func ParseNext(tokenizer *Tokenizer) (Statement, error) {
 // SplitStatement returns the first sql statement up to either a ; or EOF
 // and the remainder from the given buffer
 func SplitStatement(blob string) (string, string, error) {
-	tokenizer := NewStringTokenizer(blob)
+	tokenizer := NewStringTokenizer(blob, SQLMode)
 	tkn := 0
 	for {
 		tkn, _ = tokenizer.Scan()
@@ -118,7 +125,7 @@ func SplitStatement(blob string) (string, string, error) {
 // returns the sql pieces blob contains; or error if sql cannot be parsed
 func SplitStatementToPieces(blob string) (pieces []string, err error) {
 	pieces = make([]string, 0, 16)
-	tokenizer := NewStringTokenizer(blob)
+	tokenizer := NewStringTokenizer(blob, SQLMode)
 
 	tkn := 0
 	var stmt string
@@ -3430,6 +3437,12 @@ func Backtick(in string) string {
 }
 
 func formatID(buf *TrackedBuffer, original, lowered string) {
+	var identChar rune
+	if SQLMode == SQLModeANSIQuotes {
+		identChar = '"'
+	} else {
+		identChar = '`'
+	}
 	isDbSystemVariable := false
 	if len(original) > 1 && original[:2] == "@@" {
 		isDbSystemVariable = true
@@ -3449,14 +3462,14 @@ func formatID(buf *TrackedBuffer, original, lowered string) {
 	return
 
 mustEscape:
-	buf.WriteByte('`')
+	_, _ = buf.WriteRune(identChar)
 	for _, c := range original {
-		buf.WriteRune(c)
-		if c == '`' {
-			buf.WriteByte('`')
+		_, _ = buf.WriteRune(c)
+		if c == identChar {
+			_, _ = buf.WriteRune(identChar)
 		}
 	}
-	buf.WriteByte('`')
+	_, _ = buf.WriteRune(identChar)
 }
 
 func compliantName(in string) string {

parse_next_test.go

@@ -67,7 +67,7 @@ func TestParseNextErrors(t *testing.T) {
 		}
 
 		sql := tcase.input + "; select 1 from t"
-		tokens := NewStringTokenizer(sql)
+		tokens := NewStringTokenizer(sql, SQLMode)
 
 		// The first statement should be an error
 		_, err := ParseNext(tokens)
@@ -136,13 +136,12 @@ func TestParseNextEdgeCases(t *testing.T) {
 	}}
 
 	for _, test := range tests {
-		tokens := NewStringTokenizer(test.input)
+		tokens := NewStringTokenizer(test.input, SQLMode)
 
 		for i, want := range test.want {
 			tree, err := ParseNext(tokens)
 			if err != nil {
 				t.Fatalf("[%d] ParseNext(%q) err = %q, want nil", i, test.input, err)
-				continue
 			}
 
 			if got := String(tree); got != want {

token.go

@@ -44,6 +44,7 @@ type Tokenizer struct {
 	posVarIndex    int
 	ParseTree      Statement
 	partialDDL     *DDL
+	sqlMode        int
 	nesting        int
 	multi          bool
 	specialComment *Tokenizer
@@ -55,11 +56,12 @@ type Tokenizer struct {
 
 // NewStringTokenizer creates a new Tokenizer for the
 // sql string.
-func NewStringTokenizer(sql string) *Tokenizer {
+func NewStringTokenizer(sql string, sqlMode int) *Tokenizer {
 	buf := []byte(sql)
 	return &Tokenizer{
 		buf:     buf,
 		bufSize: len(buf),
+		sqlMode: sqlMode,
 	}
 }
 
@@ -595,7 +597,12 @@ func (tkn *Tokenizer) Scan() (int, []byte) {
 				return NE, nil
 			}
 			return int(ch), nil
-		case '\'', '"':
+		case '\'':
+			return tkn.scanString(ch, STRING)
+		case '"':
+			if tkn.sqlMode == SQLModeANSIQuotes {
+				return tkn.scanLiteralIdentifier()
+			}
 			return tkn.scanString(ch, STRING)
 		case '`':
 			return tkn.scanLiteralIdentifier()
@@ -667,25 +674,41 @@ func (tkn *Tokenizer) scanBitLiteral() (int, []byte) {
 func (tkn *Tokenizer) scanLiteralIdentifier() (int, []byte) {
 	buffer := &bytes2.Buffer{}
 	backTickSeen := false
+	quoteSeen := false
 	for {
 		if backTickSeen {
 			if tkn.lastChar != '`' {
 				break
 			}
 			backTickSeen = false
-			buffer.WriteByte('`')
+			_ = buffer.WriteByte('`')
+			tkn.next()
+			continue
+		}
+		if quoteSeen {
+			if tkn.lastChar != '"' {
+				break
+			}
+			quoteSeen = false
+			_ = buffer.WriteByte('"')
 			tkn.next()
 			continue
 		}
 		// The previous char was not a backtick.
 		switch tkn.lastChar {
 		case '`':
 			backTickSeen = true
+		case '"':
+			if tkn.sqlMode == SQLModeANSIQuotes {
+				quoteSeen = true
+			} else {
+				_ = buffer.WriteByte(byte(tkn.lastChar))
+			}
 		case eofChar:
 			// Premature EOF.
 			return LEX_ERROR, buffer.Bytes()
 		default:
-			buffer.WriteByte(byte(tkn.lastChar))
+			_ = buffer.WriteByte(byte(tkn.lastChar))
 		}
 		tkn.next()
 	}
@@ -880,7 +903,7 @@ func (tkn *Tokenizer) scanMySQLSpecificComment() (int, []byte) {
 		tkn.consumeNext(buffer)
 	}
 	_, sql := ExtractMysqlComment(buffer.String())
-	tkn.specialComment = NewStringTokenizer(sql)
+	tkn.specialComment = NewStringTokenizer(sql, SQLMode)
 	return tkn.Scan()
 }
 

token_test.go

@@ -57,7 +57,7 @@ func TestLiteralID(t *testing.T) {
 	}}
 
 	for _, tcase := range testcases {
-		tkn := NewStringTokenizer(tcase.in)
+		tkn := NewStringTokenizer(tcase.in, SQLMode)
 		id, out := tkn.Scan()
 		if tcase.id != id || string(out) != tcase.out {
 			t.Errorf("Scan(%s): %d, %s, want %d, %s", tcase.in, id, out, tcase.id, tcase.out)
@@ -130,7 +130,7 @@ func TestString(t *testing.T) {
 	}}
 
 	for _, tcase := range testcases {
-		id, got := NewStringTokenizer(tcase.in).Scan()
+		id, got := NewStringTokenizer(tcase.in, SQLMode).Scan()
 		if tcase.id != id || string(got) != tcase.want {
 			t.Errorf("Scan(%q) = (%s, %q), want (%s, %q)", tcase.in, tokenName(id), got, tokenName(tcase.id), tcase.want)
 		}
@@ -189,3 +189,31 @@ func TestSplitStatement(t *testing.T) {
 		}
 	}
 }
+
+func TestParseANSIQuotesMode(t *testing.T) {
+	testcases := []struct {
+		in  string
+		out string
+	}{{
+		in:  `select * from "table"`,
+		out: `select * from "table"`,
+	}, {
+		in:  `select * from "tbl"`,
+		out: `select * from tbl`,
+	}}
+
+	SQLMode = SQLModeANSIQuotes
+	for _, tcase := range testcases {
+		stmt, err := Parse(tcase.in)
+		if err != nil {
+			t.Errorf("EndOfStatementPosition(%s): ERROR: %v", tcase.in, err)
+			continue
+		}
+
+		finalSQL := String(stmt)
+		if tcase.out != finalSQL {
+			t.Errorf("EndOfStatementPosition(%s) got sql \"%s\" want \"%s\"", tcase.in, finalSQL, tcase.out)
+		}
+	}
+	SQLMode = SQLModeStandard
+}

tracked_buffer.go

@@ -68,7 +68,7 @@ func (buf *TrackedBuffer) Myprintf(format string, values ...interface{}) {
 			i++
 		}
 		if i > lasti {
-			buf.WriteString(format[lasti:i])
+			_, _ = buf.WriteString(format[lasti:i])
 		}
 		if i >= end {
 			break
@@ -78,18 +78,18 @@ func (buf *TrackedBuffer) Myprintf(format string, values ...interface{}) {
 		case 'c':
 			switch v := values[fieldnum].(type) {
 			case byte:
-				buf.WriteByte(v)
+				_ = buf.WriteByte(v)
 			case rune:
-				buf.WriteRune(v)
+				_, _ = buf.WriteRune(v)
 			default:
 				panic(fmt.Sprintf("unexpected TrackedBuffer type %T", v))
 			}
 		case 's':
 			switch v := values[fieldnum].(type) {
 			case []byte:
-				buf.Write(v)
+				_, _ = buf.Write(v)
 			case string:
-				buf.WriteString(v)
+				_, _ = buf.WriteString(v)
 			default:
 				panic(fmt.Sprintf("unexpected TrackedBuffer type %T", v))
 			}
@@ -118,7 +118,7 @@ func (buf *TrackedBuffer) WriteArg(arg string) {
 		offset: buf.Len(),
 		length: len(arg),
 	})
-	buf.WriteString(arg)
+	_, _ = buf.WriteString(arg)
 }
 
 // ParsedQuery returns a ParsedQuery that contains bind