content: /*
   * Copyright 2021-2022 Alibaba Group Holding Ltd.
   *
   *    Licensed under the Apache License, Version 2.0 (the "License");
   *    you may not use this file except in compliance with the License.
   *    You may obtain a copy of the License at
   *
   *      http://www.apache.org/licenses/LICENSE-2.0
   *
   *    Unless required by applicable law or agreed to in writing, software
   *    distributed under the License is distributed on an "AS IS" BASIS,
   *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   *    See the License for the specific language governing permissions and
   *    limitations under the License.
   */
  
  package com.aliyun.fastmodel.core.tree.statement.table.constraint;
  
  import java.util.List;
  
  import com.aliyun.fastmodel.core.tree.AstVisitor;
  import com.aliyun.fastmodel.core.tree.Node;
  import com.aliyun.fastmodel.core.tree.expr.Identifier;
  import com.aliyun.fastmodel.core.tree.statement.constants.ConstraintType;
  import com.google.common.collect.ImmutableList;
  import lombok.Data;
  import lombok.EqualsAndHashCode;
  import lombok.Getter;
  
  /**
   * 非空约束
   *
   * @author panguanjing
   * @date 2020/11/6
   */
  @Getter
  @EqualsAndHashCode(callSuper = false)
  public class NotNullConstraint extends BaseConstraint {
  
      public NotNullConstraint(Identifier constraintName, Boolean enable) {
          super(constraintName, ConstraintType.NOT_NULL, enable);
      }
  
      public NotNullConstraint(Identifier constraintName) {
          this(constraintName, true);
      }
  
      @Override
      public List<? extends Node> getChildren() {
          return ImmutableList.of();
      }
  
      @Override
      public <R, C> R accept(AstVisitor<R, C> visitor, C context) {
          return visitor.visitNotNullConstraint(this, context);
      }
  }
  
  
  