DropTableStatement.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 Deveel.Data.Serialization;
using Deveel.Data.Sql.Tables;

namespace Deveel.Data.Sql.Statements {
    public sealed class DropTableStatement : SqlStatement, IPreparableStatement {
        public DropTableStatement(string[] tableNames) 
            : this(tableNames, false) {
        }

        public DropTableStatement(string[] tableNames, bool ifExists) {
            if (tableNames == null)
                throw new ArgumentNullException("tableNames");
            if (tableNames.Length == 0)
                throw new ArgumentException("The table name list cannot be empty", "tableNames");

            if (tableNames.Any(String.IsNullOrEmpty))
                throw new ArgumentException("One of the specified table names is null.");

            TableNames = tableNames;
            IfExists = ifExists;
        }

        public DropTableStatement(string tableName)
            : this(tableName, false) {
        }

        public DropTableStatement(string tableName, bool ifExists)
            : this(new[] {tableName}, ifExists) {
        }

        public string[] TableNames { get; private set; }

        public bool IfExists { get; set; }

        IStatement IPreparableStatement.Prepare(IRequest context) {
            var tableNameList = TableNames.ToList();
            var dropTables = new List<string>();

            foreach (var tableName in tableNameList) {
                if (dropTables.Contains(tableName, StringComparer.OrdinalIgnoreCase))
                    throw new StatementPrepareException(String.Format("Duplicated table name '{0}' in the list of tables to drop.",
                        tableName));

                dropTables.Add(tableName);
            }

            var resolvedTableNames = dropTables.Select(context.Query.ResolveTableName);

            return new Prepared(resolvedTableNames.ToArray(), IfExists);
        }

        #region Prepared

        [Serializable]
        class Prepared : SqlStatement {
            public Prepared(ObjectName[] tableNames, bool ifExists) {
                TableNames = tableNames;
                IfExists = ifExists;
            }

            private Prepared(ObjectData data) {
                TableNames = data.GetValue<ObjectName[]>("TableNames");
                IfExists = data.GetBoolean("IfExists");
            }

            public ObjectName[] TableNames { get; private set; }

            public bool IfExists { get; private set; }

            protected override void GetData(SerializeData data) {
                data.SetValue("TableNames", TableNames);
                data.SetValue("IfExists", IfExists);
            }

            protected override void ExecuteStatement(ExecutionContext context) {
                context.Request.Query.DropTables(TableNames, IfExists);
            }
        }

        #endregion
    }
}