improved sql parser.

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

@@ -21,6 +21,7 @@ import static com.alibaba.druid.sql.parser.CharTypes.isWhitespace;
 import static com.alibaba.druid.sql.parser.LayoutCharacters.EOI;
 import static com.alibaba.druid.sql.parser.SQLParserFeature.KeepComments;
 import static com.alibaba.druid.sql.parser.SQLParserFeature.OptimizedForParameterized;
+import static com.alibaba.druid.sql.parser.SQLParserFeature.SkipComments;
 import static com.alibaba.druid.sql.parser.Token.*;
 
 import java.math.BigDecimal;
@@ -1924,6 +1925,8 @@ public class Lexer {
             optimizedForParameterized = state;
         } else if (feature == KeepComments) {
             this.keepComments = state;
+        } else if (feature == SkipComments) {
+            this.skipComment = state;
         }
     }
 

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

@@ -2034,13 +2034,21 @@ public class SQLExprParser extends SQLParser {
             }
         } else if (lexer.token == Token.IN) {
             lexer.nextToken();
-            accept(Token.LPAREN);
 
             SQLInListExpr inListExpr = new SQLInListExpr(expr, true);
-            exprList(inListExpr.getTargetList(), inListExpr);
-            expr = inListExpr;
+            if (lexer.token == Token.LPAREN) {
+                lexer.nextToken();
 
-            accept(Token.RPAREN);
+                exprList(inListExpr.getTargetList(), inListExpr);
+                expr = inListExpr;
+
+                accept(Token.RPAREN);
+            } else {
+                SQLExpr valueExpr = this.primary();
+                valueExpr.setParent(inListExpr);
+                inListExpr.getTargetList().add(valueExpr);
+                expr = inListExpr;
+            }
 
             if (inListExpr.getTargetList().size() == 1) {
                 SQLExpr targetExpr = inListExpr.getTargetList().get(0);
@@ -2670,14 +2678,17 @@ public class SQLExprParser extends SQLParser {
 
             if (token == Token.AS) {
                 lexer.nextToken();
-                String as = lexer.stringVal();
+                String as = null;
+                if (lexer.token != Token.COMMA && lexer.token != Token.FROM) {
+                    as = lexer.stringVal();
 
-                lexer.nextTokenComma();
+                    lexer.nextTokenComma();
 
-                if (lexer.token == Token.DOT) {
-                    lexer.nextToken();
-                    as += '.' + lexer.stringVal();
-                    lexer.nextToken();
+                    if (lexer.token == Token.DOT) {
+                        lexer.nextToken();
+                        as += '.' + lexer.stringVal();
+                        lexer.nextToken();
+                    }
                 }
 
                 return new SQLSelectItem(expr, as, connectByRoot);
@@ -2689,7 +2700,8 @@ public class SQLExprParser extends SQLParser {
                 return new SQLSelectItem(expr, as, connectByRoot);
             }
 
-            if (token == Token.IDENTIFIER && hash_lower != FnvHash.Constants.CURRENT) {
+            if ((token == Token.IDENTIFIER && hash_lower != FnvHash.Constants.CURRENT)
+                    || token == Token.MODEL) {
                 String as = lexer.stringVal();
                 lexer.nextTokenComma();
                 return new SQLSelectItem(expr, as, connectByRoot);
@@ -2716,6 +2728,7 @@ public class SQLExprParser extends SQLParser {
         final String alias;
         switch (lexer.token) {
             case FULL:
+            case MODEL:
                 alias = lexer.stringVal();
                 lexer.nextToken();
                 break;

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

@@ -19,7 +19,8 @@ public enum SQLParserFeature {
     KeepInsertValueClauseOriginalString,
     EnableSQLBinaryOpExprGroup,
     OptimizedForParameterized,
-    KeepComments
+    KeepComments,
+    SkipComments
     ;
 
     private SQLParserFeature(){

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

@@ -21,11 +21,12 @@ import com.alibaba.druid.sql.ast.statement.SQLSelectQueryBlock;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;
+import java.util.concurrent.CopyOnWriteArrayList;
 
 public class SQLSelectListCache {
     private final String dbType;
-    private List<String> sqlCache = new ArrayList<String>();
-    private List<SQLSelectQueryBlock> queryBlockCache = new ArrayList<SQLSelectQueryBlock>();
+    private List<String> sqlCache = new CopyOnWriteArrayList<String>();
+    private List<SQLSelectQueryBlock> queryBlockCache = new CopyOnWriteArrayList<SQLSelectQueryBlock>();
     private List<String> printSqlList = new ArrayList<String>();
 
     public SQLSelectListCache(String dbType) {

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

@@ -2621,7 +2621,7 @@ public class SQLStatementParser extends SQLParser {
     public SQLOpenStatement parseOpen() {
         SQLOpenStatement stmt = new SQLOpenStatement();
         accept(Token.OPEN);
-        stmt.setCursorName(exprParser.name().getSimpleName());
+        stmt.setCursorName(exprParser.name());
 
         if (lexer.token == Token.LPAREN) {
             lexer.nextToken();
@@ -2674,7 +2674,7 @@ public class SQLStatementParser extends SQLParser {
     public SQLStatement parseClose() {
         SQLCloseStatement stmt = new SQLCloseStatement();
         accept(Token.CLOSE);
-        stmt.setCursorName(exprParser.name().getSimpleName());
+        stmt.setCursorName(exprParser.name());
         accept(Token.SEMI);
         stmt.setAfterSemi(true);
         return stmt;