improve test case for sql variant ref expr ;

improve test cast for parameterized

src/main/java/com/alibaba/druid/sql/ast/expr/SQLVariantRefExpr.java

@@ -30,7 +30,7 @@ public class SQLVariantRefExpr extends SQLExprImpl {
 
     private boolean global = false;
 
-    private boolean hasSessionBefore = false;
+    private boolean session = false;
 
     private int     index  = -1;
 
@@ -43,10 +43,10 @@ public class SQLVariantRefExpr extends SQLExprImpl {
         this.global = global;
     }
 
-    public SQLVariantRefExpr(String name, boolean global,boolean hasSessionBefore){
+    public SQLVariantRefExpr(String name, boolean global,boolean session){
         this.name = name;
         this.global = global;
-        this.hasSessionBefore = hasSessionBefore;
+        this.session = session;
     }
 
     public SQLVariantRefExpr(){
@@ -74,12 +74,12 @@ public class SQLVariantRefExpr extends SQLExprImpl {
     }
 
 
-    public boolean isHasSessionBefore() {
-        return hasSessionBefore;
+    public boolean isSession() {
+        return session;
     }
 
-    public void setHasSessionBefore(boolean hasSessionBefore) {
-        this.hasSessionBefore = hasSessionBefore;
+    public void setSession(boolean session) {
+        this.session = session;
     }
 
     @Override

src/main/java/com/alibaba/druid/sql/dialect/mysql/ast/statement/MySqlSetTransactionStatement.java

@@ -29,15 +29,15 @@ public class MySqlSetTransactionStatement extends MySqlStatementImpl {
 
     private String  accessModel;
 
-    private Boolean hasSessionBefore;
+    private Boolean session;
 
 
-    public Boolean getHasSessionBefore() {
-        return hasSessionBefore;
+    public Boolean getSession() {
+        return session;
     }
 
-    public void setHasSessionBefore(Boolean hasSessionBefore) {
-        this.hasSessionBefore = hasSessionBefore;
+    public void setSession(Boolean session) {
+        this.session = session;
     }
 
     public void accept0(MySqlASTVisitor visitor) {

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

@@ -2609,20 +2609,20 @@ public class MySqlStatementParser extends SQLStatementParser {
         }
 
         Boolean global = null;
-        Boolean sessionBefore = null;
+        Boolean session = null;
         if (lexer.identifierEquals(GLOBAL)) {
             global = Boolean.TRUE;
             lexer.nextToken();
         } else if (lexer.identifierEquals(SESSION)) {
             global = Boolean.FALSE;
-            sessionBefore = Boolean.TRUE;
+            session = Boolean.TRUE;
             lexer.nextToken();
         }
 
         if (lexer.identifierEquals("TRANSACTION")) {
             MySqlSetTransactionStatement stmt = new MySqlSetTransactionStatement();
             stmt.setGlobal(global);
-            stmt.setHasSessionBefore(sessionBefore);
+            stmt.setSession(session);
 
             lexer.nextToken();
             if (lexer.identifierEquals("ISOLATION")) {
@@ -2722,14 +2722,14 @@ public class MySqlStatementParser extends SQLStatementParser {
 
             parseAssignItems(stmt.getItems(), stmt);
 
-            if (global != null && global.booleanValue()) {
+            if (global != null && global) {
                 SQLVariantRefExpr varRef = (SQLVariantRefExpr) stmt.getItems().get(0).getTarget();
                 varRef.setGlobal(true);
             }
 
-            if(sessionBefore != null && sessionBefore.booleanValue()){
+            if(session != null && session){
                 SQLVariantRefExpr varRef = (SQLVariantRefExpr) stmt.getItems().get(0).getTarget();
-                varRef.setHasSessionBefore(true);
+                varRef.setSession(true);
             }
 
             if (lexer.token() == Token.HINT) {

src/main/java/com/alibaba/druid/sql/dialect/mysql/visitor/MySqlOutputVisitor.java

@@ -655,7 +655,7 @@ public class MySqlOutputVisitor extends SQLASTOutputVisitor implements MySqlASTV
 
         if (x.isGlobal()) {
             print0("@@global.");
-        }else if(x.isHasSessionBefore()){
+        }else if(x.isSession()){
             print0("@@session.");
         }