improved sql parser schema repository.

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

@@ -314,11 +314,13 @@ public class MySqlCreateTableStatement extends SQLCreateTableStatement implement
             }
         }
 
-        for (SQLTableElement e : tableElementList) {
+        for (int i = 0; i < tableElementList.size(); i++) {
+            SQLTableElement e = tableElementList.get(i);
             if(e instanceof MySqlTableIndex) {
-                ((MySqlTableIndex) e).apply(item);
-            } else if (e instanceof MySqlKey) {
-                ((MySqlKey) e).applyColumnRename(columnName, column.getName());
+                ((MySqlTableIndex) e).applyColumnRename(columnName, column.getName());
+            } else if (e instanceof SQLUnique) {
+                SQLUnique unique = (SQLUnique) e;
+                unique.applyColumnRename(columnName, column.getName());
             }
         }
 

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

@@ -18,6 +18,7 @@ package com.alibaba.druid.sql.dialect.mysql.ast.statement;
 import java.util.ArrayList;
 import java.util.List;
 
+import com.alibaba.druid.sql.SQLUtils;
 import com.alibaba.druid.sql.ast.SQLExpr;
 import com.alibaba.druid.sql.ast.SQLName;
 import com.alibaba.druid.sql.ast.statement.SQLColumnDefinition;
@@ -85,7 +86,27 @@ public class MySqlTableIndex extends MySqlObjectImpl implements SQLTableElement
         return x;
     }
 
-    public boolean apply(MySqlAlterTableChangeColumn x) {
+    public boolean applyColumnRename(SQLName columnName, SQLName to) {
+        for (SQLSelectOrderByItem orderByItem : columns) {
+            SQLExpr expr = orderByItem.getExpr();
+            if (expr instanceof SQLName
+                    && SQLUtils.nameEquals((SQLName) expr, columnName)) {
+                orderByItem.setExpr(to.clone());
+                return true;
+            }
+        }
+        return false;
+    }
+
+    public boolean applyDropColumn(SQLName columnName) {
+        for (int i = columns.size() - 1; i >= 0; i--) {
+            SQLExpr expr = columns.get(i).getExpr();
+            if (expr instanceof SQLName
+                    && SQLUtils.nameEquals((SQLName) expr, columnName)) {
+                columns.remove(i);
+                return true;
+            }
+        }
         return false;
     }
 }