sql parser schema stat

src/main/java/com/alibaba/druid/sql/dialect/postgresql/visitor/PGEvalVisitor.java

@@ -0,0 +1,64 @@
+package com.alibaba.druid.sql.dialect.postgresql.visitor;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import com.alibaba.druid.sql.ast.expr.SQLBinaryOpExpr;
+import com.alibaba.druid.sql.ast.expr.SQLCharExpr;
+import com.alibaba.druid.sql.ast.expr.SQLVariantRefExpr;
+import com.alibaba.druid.sql.visitor.SQLEvalVisitor;
+import com.alibaba.druid.sql.visitor.SQLEvalVisitorUtils;
+
+
+public class PGEvalVisitor extends PGASTVisitorAdapter implements SQLEvalVisitor {
+    private List<Object> parameters       = new ArrayList<Object>();
+
+    private int          variantIndex     = -1;
+
+    private boolean      markVariantIndex = true;
+
+    public PGEvalVisitor(){
+        this(new ArrayList<Object>(1));
+    }
+
+    public PGEvalVisitor(List<Object> parameters){
+        this.parameters = parameters;
+    }
+
+    public List<Object> getParameters() {
+        return parameters;
+    }
+
+    public void setParameters(List<Object> parameters) {
+        this.parameters = parameters;
+    }
+
+    public boolean visit(SQLCharExpr x) {
+        return SQLEvalVisitorUtils.visit(this, x);
+    }
+
+    public int incrementAndGetVariantIndex() {
+        return ++variantIndex;
+    }
+
+    public int getVariantIndex() {
+        return variantIndex;
+    }
+
+    public boolean visit(SQLVariantRefExpr x) {
+        return SQLEvalVisitorUtils.visit(this, x);
+    }
+
+    public boolean visit(SQLBinaryOpExpr x) {
+        return SQLEvalVisitorUtils.visit(this, x);
+    }
+
+    public boolean isMarkVariantIndex() {
+        return markVariantIndex;
+    }
+
+    public void setMarkVariantIndex(boolean markVariantIndex) {
+        this.markVariantIndex = markVariantIndex;
+    }
+
+}

src/main/java/com/alibaba/druid/sql/dialect/postgresql/visitor/PGSchemaStatVisitor.java

@@ -23,9 +23,15 @@ import com.alibaba.druid.sql.dialect.postgresql.ast.stmt.PGUpdateStatement;
 import com.alibaba.druid.sql.visitor.SchemaStatVisitor;
 import com.alibaba.druid.stat.TableStat;
 import com.alibaba.druid.stat.TableStat.Mode;
+import com.alibaba.druid.util.JdbcUtils;
 
 public class PGSchemaStatVisitor extends SchemaStatVisitor implements PGASTVisitor {
 
+    @Override
+    public String getDbType() {
+        return JdbcUtils.POSTGRESQL;
+    }
+    
     @Override
     public void endVisit(WindowClause x) {