UpdateStatementNode.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.Collections.Generic;
using System.Linq;
using System.Linq.Expressions;

using Deveel.Data.Sql.Statements;

namespace Deveel.Data.Sql.Parser {
    class UpdateStatementNode : SqlStatementNode {
        public SimpleUpdateNode SimpleUpdate { get; private set; }

        public QueryUpdateNode QueryUpdate { get; private set; }

        protected override ISqlNode OnChildNode(ISqlNode node) {
            if (node is SimpleUpdateNode) {
                SimpleUpdate = (SimpleUpdateNode) node;
            } else if (node is QueryUpdateNode) {
                QueryUpdate = (QueryUpdateNode) node;
            }

            return base.OnChildNode(node);
        }

        protected override void BuildStatement(StatementBuilder builder) {
            if (SimpleUpdate != null) {
                BuildSimpleUpdate(builder, SimpleUpdate);
            } else if (QueryUpdate != null) {
                BuildQueryUpdate(builder, QueryUpdate);
            }
        }

        private void BuildSimpleUpdate(StatementBuilder builder, SimpleUpdateNode node) {
            var whereExpression = ExpressionBuilder.Build(node.WhereExpression);
            var assignments = UpdateAssignments(node.Columns);
            builder.Statements.Add(new UpdateStatement(node.TableName, whereExpression, assignments));
        }

        private IEnumerable<SqlColumnAssignment> UpdateAssignments(IEnumerable<UpdateColumnNode> columns) {
            if (columns == null)
                return null;

            return columns.Select(column => new SqlColumnAssignment(column.ColumnName, ExpressionBuilder.Build(column.Expression)));
        }

        private void BuildQueryUpdate(StatementBuilder builder, QueryUpdateNode node) {
            throw new NotImplementedException();
        }
    }
}