bug fixed for concurrent & sql schema stat

src/main/java/com/alibaba/druid/pool/ConnectionHolder.java

@@ -39,7 +39,7 @@ public final class ConnectionHolder {
     private final List<ConnectionEventListener> connectionEventListeners = new CopyOnWriteArrayList<ConnectionEventListener>();
     private final List<StatementEventListener>  statementEventListeners  = new CopyOnWriteArrayList<StatementEventListener>();
     private final long                          connecttimeMillis;
-    private long                                lastActiveTimeMillis;
+    private transient long                      lastActiveTimeMillis;
     private long                                useCount                 = 0;
 
     private PreparedStatementPool               statementPool;
@@ -67,14 +67,15 @@ public final class ConnectionHolder {
         this.lastActiveTimeMillis = connecttimeMillis;
 
         this.underlyingAutoCommit = conn.getAutoCommit();
-        this.underlyingHoldability =  conn.getHoldability();
+        this.underlyingHoldability = conn.getHoldability();
         this.underlyingReadOnly = conn.isReadOnly();
         try {
             this.underlyingTransactionIsolation = conn.getTransactionIsolation();
         } catch (SQLException e) {
-            if ("com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException".equals(e.getClass().getName()));
+            if ("com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException".equals(e.getClass().getName()))
+            ;
         }
-        
+
         this.defaultHoldability = underlyingHoldability;
         this.defaultTransactionIsolation = underlyingTransactionIsolation;
         this.defaultAutoCommit = underlyingAutoCommit;

src/main/java/com/alibaba/druid/sql/dialect/oracle/visitor/OracleSchemaStatVisitor.java

@@ -318,7 +318,6 @@ public class OracleSchemaStatVisitor extends SchemaStatVisitor implements Oracle
     }
 
     public void endVisit(OracleUpdateStatement x) {
-        clearAliasMap();
     }
 
     public boolean visit(OracleDeleteStatement x) {
@@ -326,7 +325,6 @@ public class OracleSchemaStatVisitor extends SchemaStatVisitor implements Oracle
     }
 
     public void endVisit(OracleDeleteStatement x) {
-        clearAliasMap();
     }
 
     public boolean visit(OracleSelectQueryBlock x) {
@@ -1035,7 +1033,6 @@ public class OracleSchemaStatVisitor extends SchemaStatVisitor implements Oracle
 
     @Override
     public void endVisit(OracleMergeStatement x) {
-        clearAliasMap();
     }
 
     @Override

src/main/java/com/alibaba/druid/sql/visitor/SchemaStatVisitor.java

@@ -723,7 +723,6 @@ public class SchemaStatVisitor extends SQLASTVisitorAdapter {
     }
 
     public void endVisit(SQLSelectStatement x) {
-        clearAliasMap();
     }
 
     public boolean visit(SQLSubqueryTableSource x) {
@@ -897,11 +896,10 @@ public class SchemaStatVisitor extends SQLASTVisitorAdapter {
     }
 
     public void endVisit(SQLDeleteStatement x) {
-        clearAliasMap();
+        
     }
 
     public void endVisit(SQLUpdateStatement x) {
-        clearAliasMap();
     }
 
     public boolean visit(SQLCreateTableStatement x) {

src/main/java/com/alibaba/druid/stat/TableStat.java

@@ -337,7 +337,26 @@ public class TableStat {
         }
 
         public String toString() {
-            return this.column.toString() + " " + this.operator;
+            StringBuffer buf = new StringBuffer();
+            buf.append(this.column.toString());
+            buf.append(' ');
+            buf.append(this.operator);
+
+            if (values.size() == 1) {
+                buf.append(' ');
+                buf.append(String.valueOf(this.values.get(0)));
+            } else if (values.size() > 0) {
+                buf.append(" (");
+                for (int i = 0; i < values.size(); ++i) {
+                    if (i != 0) {
+                        buf.append(", ");
+                    }
+                    buf.append(String.valueOf(values.get(i)));
+                }
+                buf.append(")");
+            }
+
+            return buf.toString();
         }
     }