SchemaStatVisitor support relationship

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

@@ -22,6 +22,15 @@ public class TableStat {
     int deleteCount = 0;
     int insertCount = 0;
     int dropCount   = 0;
+    int mergeCount  = 0;
+
+    public int getMergeCount() {
+        return mergeCount;
+    }
+
+    public void incrementMergeCount() {
+        this.mergeCount++;
+    }
 
     public int getDropCount() {
         return dropCount;
@@ -85,6 +94,9 @@ public class TableStat {
 
     public String toString() {
         StringBuilder buf = new StringBuilder(4);
+        if (mergeCount > 0) {
+            buf.append("Merge");
+        }
         if (insertCount > 0) {
             buf.append("Insert");
         }
@@ -135,6 +147,89 @@ public class TableStat {
         }
     }
 
+    public static class Relationship {
+
+        private Column left;
+        private Column right;
+        private String operator;
+
+        public Column getLeft() {
+            return left;
+        }
+
+        public void setLeft(Column left) {
+            this.left = left;
+        }
+
+        public Column getRight() {
+            return right;
+        }
+
+        public void setRight(Column right) {
+            this.right = right;
+        }
+
+        public String getOperator() {
+            return operator;
+        }
+
+        public void setOperator(String operator) {
+            this.operator = operator;
+        }
+
+        @Override
+        public int hashCode() {
+            final int prime = 31;
+            int result = 1;
+            result = prime * result + ((left == null) ? 0 : left.hashCode());
+            result = prime * result + ((operator == null) ? 0 : operator.hashCode());
+            result = prime * result + ((right == null) ? 0 : right.hashCode());
+            return result;
+        }
+
+        @Override
+        public boolean equals(Object obj) {
+            if (this == obj) {
+                return true;
+            }
+            if (obj == null) {
+                return false;
+            }
+            if (getClass() != obj.getClass()) {
+                return false;
+            }
+            Relationship other = (Relationship) obj;
+            if (left == null) {
+                if (other.left != null) {
+                    return false;
+                }
+            } else if (!left.equals(other.left)) {
+                return false;
+            }
+            if (operator == null) {
+                if (other.operator != null) {
+                    return false;
+                }
+            } else if (!operator.equals(other.operator)) {
+                return false;
+            }
+            if (right == null) {
+                if (other.right != null) {
+                    return false;
+                }
+            } else if (!right.equals(other.right)) {
+                return false;
+            }
+            return true;
+        }
+
+        @Override
+        public String toString() {
+            return left + " " + operator + " " + right;
+        }
+
+    }
+
     public static class Condition {
 
         private Column column;
@@ -272,7 +367,7 @@ public class TableStat {
     }
 
     public static enum Mode {
-        Insert(1), Update(2), Delete(4), Select(8);
+        Insert(1), Update(2), Delete(4), Select(8), Merge(16);
 
         public final int mark;