improved support hints.

src/main/java/com/alibaba/druid/sql/ast/statement/SQLCharacterDataType.java

@@ -15,9 +15,12 @@
  */
 package com.alibaba.druid.sql.ast.statement;
 
+import com.alibaba.druid.sql.ast.SQLCommentHint;
 import com.alibaba.druid.sql.ast.SQLDataTypeImpl;
 import com.alibaba.druid.sql.visitor.SQLASTVisitor;
 
+import java.util.List;
+
 public class SQLCharacterDataType extends SQLDataTypeImpl {
 
     private String             charSetName;
@@ -26,6 +29,8 @@ public class SQLCharacterDataType extends SQLDataTypeImpl {
     private String             charType;
     private boolean            hasBinary;
 
+    public List<SQLCommentHint> hints;
+
     public final static String CHAR_TYPE_BYTE = "BYTE";
     public final static String CHAR_TYPE_CHAR = "CHAR";
 
@@ -65,6 +70,14 @@ public class SQLCharacterDataType extends SQLDataTypeImpl {
         this.charType = charType;
     }
 
+    public List<SQLCommentHint> getHints() {
+        return hints;
+    }
+
+    public void setHints(List<SQLCommentHint> hints) {
+        this.hints = hints;
+    }
+
     @Override
     protected void accept0(SQLASTVisitor visitor) {
         if (visitor.visit(this)) {

src/main/java/com/alibaba/druid/sql/ast/statement/SQLConstraintImpl.java

@@ -15,18 +15,33 @@
  */
 package com.alibaba.druid.sql.ast.statement;
 
+import com.alibaba.druid.sql.ast.SQLCommentHint;
 import com.alibaba.druid.sql.ast.SQLName;
 import com.alibaba.druid.sql.ast.SQLObjectImpl;
 
+import java.util.List;
+
 public abstract class SQLConstraintImpl extends SQLObjectImpl implements SQLConstraint {
 
     private SQLName name;
     private Boolean enable;
 
+    public List<SQLCommentHint> hints;
+
     public SQLConstraintImpl(){
 
     }
 
+
+    public List<SQLCommentHint> getHints() {
+        return hints;
+    }
+
+    public void setHints(List<SQLCommentHint> hints) {
+        this.hints = hints;
+    }
+
+
     public SQLName getName() {
         return name;
     }

src/main/java/com/alibaba/druid/sql/ast/statement/SQLNotNullConstraint.java

@@ -15,10 +15,15 @@
  */
 package com.alibaba.druid.sql.ast.statement;
 
+import com.alibaba.druid.sql.ast.SQLCommentHint;
 import com.alibaba.druid.sql.visitor.SQLASTVisitor;
 
+import java.util.List;
+
 public class SQLNotNullConstraint extends SQLConstraintImpl implements SQLColumnConstraint {
 
+
+
     public SQLNotNullConstraint(){
 
     }

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

@@ -405,6 +405,14 @@ public class MySqlOutputVisitor extends SQLASTOutputVisitor implements MySqlASTV
                     print0(charType.getCollate());
                 }
             }
+
+            List<SQLCommentHint> hints = ((SQLCharacterDataType) x).hints;
+            if (hints != null) {
+                print(' ');
+                for (SQLCommentHint hint : hints) {
+                    hint.accept(this);
+                }
+            }
         }
         return false;
     }
@@ -434,6 +442,14 @@ public class MySqlOutputVisitor extends SQLASTOutputVisitor implements MySqlASTV
             print0(x.getCollate());
         }
 
+        List<SQLCommentHint> hints = ((SQLCharacterDataType) x).hints;
+        if (hints != null) {
+            print(' ');
+            for (SQLCommentHint hint : hints) {
+                hint.accept(this);
+            }
+        }
+
         return false;
     }
 

src/main/java/com/alibaba/druid/sql/parser/SQLExprParser.java

@@ -1758,7 +1758,14 @@ public class SQLExprParser extends SQLParser {
                 accept(Token.RPAREN);
             }
 
-            return parseCharTypeRest(charType);
+            charType = (SQLCharacterDataType) parseCharTypeRest(charType);
+
+            if (lexer.token() == Token.HINT) {
+                List<SQLCommentHint> hints = this.parseHints();
+                charType.setHints(hints);
+            }
+
+            return charType;
         }
 
         if ("character".equalsIgnoreCase(typeName) && "varying".equalsIgnoreCase(lexer.stringVal())) {
@@ -1867,7 +1874,12 @@ public class SQLExprParser extends SQLParser {
         if (lexer.token() == Token.NOT) {
             lexer.nextToken();
             accept(Token.NULL);
-            column.addConstraint(new SQLNotNullConstraint());
+            SQLNotNullConstraint notNull = new SQLNotNullConstraint();
+            if (lexer.token() == Token.HINT) {
+                List<SQLCommentHint> hints = this.parseHints();
+                notNull.setHints(hints);
+            }
+            column.addConstraint(notNull);
             return parseColumnRest(column);
         }
 

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

@@ -537,6 +537,15 @@ public class SQLASTOutputVisitor extends SQLASTVisitorAdapter implements Paramet
 
     public boolean visit(SQLCharacterDataType x) {
         visit((SQLDataType) x);
+
+        List<SQLCommentHint> hints = ((SQLCharacterDataType) x).hints;
+        if (hints != null) {
+            print(' ');
+            for (SQLCommentHint hint : hints) {
+                hint.accept(this);
+            }
+        }
+
         return false;
     }
 
@@ -1678,6 +1687,16 @@ public class SQLASTOutputVisitor extends SQLASTVisitorAdapter implements Paramet
             print(' ');
         }
         print0(ucase ? "NOT NULL" : "not null");
+
+        List<SQLCommentHint> hints = x.hints;
+
+        if (hints != null) {
+            print(' ');
+            for (SQLCommentHint hint : hints) {
+                hint.accept(this);
+            }
+        }
+
         return false;
     }