refactor

src/main/java/com/alibaba/druid/sql/dialect/mysql/parser/MySqlLexer.java

@@ -102,7 +102,6 @@ public class MySqlLexer extends Lexer {
         map.put("SOME", Token.SOME);
         map.put("ANY", Token.ANY);
         map.put("TRUNCATE", Token.TRUNCATE);
-        map.put("USER", Token.USER);
         map.put("IF", Token.IF);
 
         map.put("TRUE", Token.TRUE);
@@ -110,7 +109,6 @@ public class MySqlLexer extends Lexer {
         map.put("LIMIT", Token.LIMIT);
         map.put("KILL", Token.KILL);
         map.put("IDENTIFIED", Token.IDENTIFIED);
-        map.put("PASSWORD", Token.PASSWORD);
         map.put("DUAL", Token.DUAL);
 
         DEFAULT_MYSQL_KEYWORDS = new Keywords(map);

src/main/java/com/alibaba/druid/sql/dialect/mysql/parser/MySqlStatementParser.java

@@ -192,7 +192,7 @@ public class MySqlStatementParser extends SQLStatementParser {
             return parser.parseCrateTable(false);
         }
 
-        if (lexer.token() == Token.USER) {
+        if (identifierEquals("USER")) {
             return parseCreateUser();
         }
 
@@ -200,7 +200,7 @@ public class MySqlStatementParser extends SQLStatementParser {
     }
 
     public SQLStatement parseCreateUser() throws ParserException {
-        accept(Token.USER);
+        acceptIdentifier("USER");
 
         MySqlCreateUserStatement stmt = new MySqlCreateUserStatement();
 
@@ -222,7 +222,7 @@ public class MySqlStatementParser extends SQLStatementParser {
                 if (lexer.token() == Token.BY) {
                     lexer.nextToken();
 
-                    if (lexer.token() == Token.PASSWORD) {
+                    if (identifierEquals("PASSWORD")) {
                         lexer.nextToken();
                     }
 
@@ -1264,7 +1264,7 @@ public class MySqlStatementParser extends SQLStatementParser {
     }
 
     public SQLStatement parseDropUser() throws ParserException {
-        accept(Token.USER);
+        acceptIdentifier("USER");
 
         MySqlDropUser stmt = new MySqlDropUser();
         for (;;) {

src/main/java/com/alibaba/druid/sql/dialect/postgresql/parser/PGLexer.java

@@ -82,7 +82,6 @@ public class PGLexer extends Lexer {
         map.put("SOME", Token.SOME);
         map.put("ANY", Token.ANY);
         map.put("TRUNCATE", Token.TRUNCATE);
-        map.put("USER", Token.USER);
 
         map.put("LIMIT", Token.LIMIT);
         map.put("OFFSET", Token.OFFSET);

src/main/java/com/alibaba/druid/sql/parser/SQLExprParser.java

@@ -211,8 +211,6 @@ public class SQLExprParser extends SQLParser {
                 sqlExpr = new SQLDefaultExpr();
                 lexer.nextToken();
                 break;
-            case USER:
-            case PASSWORD:
             case DUAL:
             case KEY:
             case DISTINCT:

src/main/java/com/alibaba/druid/sql/parser/SQLStatementParser.java

@@ -121,7 +121,7 @@ public class SQLStatementParser extends SQLParser {
 
                     statementList.add(stmt);
                     continue;
-                } else if (lexer.token() == Token.USER) {
+                } else if (identifierEquals("USER")) {
                     SQLStatement stmt = parseDropUser();
                     statementList.add(stmt);
                     continue;

src/main/java/com/alibaba/druid/sql/parser/Token.java

@@ -67,7 +67,6 @@ public enum Token {
     ON("ON"), 
     SCHEMA("SCHEMA"), 
     CAST("CAST"),
-    USER("USER"),
     COLUMN("COLUMN"),
     USE("USE"),