DeclareVariableNode.cs

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// 
//  Copyright 2010-2015 Deveel
// 
//    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.
//

using System;
using System.Linq;

using Deveel.Data.Sql.Statements;

namespace Deveel.Data.Sql.Parser {
    class DeclareVariableNode : SqlStatementNode, IDeclareNode {
        public string VariableName { get; private set; }

        public DataTypeNode Type { get; private set; }

        public bool IsConstant { get; private set; }

        public bool IsNotNull { get; private set; }

        public IExpressionNode DefaultExpression { get; private set; }

        protected override ISqlNode OnChildNode(ISqlNode node) {
            if (node is IdentifierNode) {
                VariableName = ((IdentifierNode) node).Text;
            } else if (node is DataTypeNode) {
                Type = (DataTypeNode)node;
            }  else if (node.NodeName.Equals("constant_opt")) {
                IsConstant = node.ChildNodes.Any();
            } else if (node.NodeName.Equals("var_not_null_opt")) {
                IsNotNull = node.ChildNodes.Any();
            } else if (node.NodeName.Equals("var_default_opt")) {
                GetDefaultExpression(node);
            }

            return base.OnChildNode(node);
        }

        private void GetDefaultExpression(ISqlNode node) {
            foreach (var childNode in node.ChildNodes) {
                if (childNode is IExpressionNode)
                    DefaultExpression = (IExpressionNode) childNode;
            }
        }

        protected override void BuildStatement(StatementBuilder builder) {
            var varType = DataTypeBuilder.Build(builder.TypeResolver, Type);
            var statement = new DeclareVariableStatement(VariableName, varType);
            if (DefaultExpression != null)
                statement.DefaultExpression = ExpressionBuilder.Build(DefaultExpression);

            statement.IsConstant = IsConstant;
            statement.IsNotNull = IsConstant || IsNotNull;
            builder.Statements.Add(statement);
        }
    }
}