/mcs/class/System.Data.Linq/src/DbLinq/Data/Linq/Implementation/QueryProvider.cs
C# | 239 lines | 114 code | 17 blank | 108 comment | 9 complexity | 0ab41400f16e8cb736a75e214f148930 MD5 | raw file
Possible License(s): MPL-2.0-no-copyleft-exception, CC-BY-SA-3.0, GPL-2.0, Unlicense
- #region MIT license
- //
- // MIT license
- //
- // Copyright (c) 2007-2008 Jiri Moudry, Pascal Craponne
- //
- // Permission is hereby granted, free of charge, to any person obtaining a copy
- // of this software and associated documentation files (the "Software"), to deal
- // in the Software without restriction, including without limitation the rights
- // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- // copies of the Software, and to permit persons to whom the Software is
- // furnished to do so, subject to the following conditions:
- //
- // The above copyright notice and this permission notice shall be included in
- // all copies or substantial portions of the Software.
- //
- // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
- // THE SOFTWARE.
- //
- #endregion
-
- using System;
- using System.Collections;
- using System.Collections.Generic;
- using System.Linq;
- using System.Linq.Expressions;
- using DbLinq.Data.Linq.Sugar;
- using DbLinq.Util;
-
- #if MONO_STRICT
- using System.Data.Linq;
- #else
- using DbLinq.Data.Linq;
- #endif
-
- namespace DbLinq.Data.Linq.Implementation
- {
- /// <summary>
- /// QueryProvider is used by both DataContext and Table
- /// to build queries
- /// It is split is two parts (non-generic and generic) for copy reasons
- /// </summary>
- internal abstract class QueryProvider
- {
- /// <summary>
- /// Gets or sets the expression chain.
- /// </summary>
- /// <value>The expression chain.</value>
- public ExpressionChain ExpressionChain { get; set; }
- /// <summary>
- /// Gets or sets the type of the table.
- /// </summary>
- /// <value>The type of the table.</value>
- public Type TableType { get; set; }
- /// <summary>
- /// Gets the query.
- /// </summary>
- /// <param name="expression">The expression.</param>
- /// <returns></returns>
- public abstract SelectQuery GetQuery(Expression expression);
- }
-
- /// <summary>
- /// QueryProvider, generic version
- /// </summary>
- /// <typeparam name="T"></typeparam>
- internal class QueryProvider<T> : QueryProvider, IQueryProvider, IQueryable<T>, IOrderedQueryable<T>
- {
- /// <summary>
- /// Holder current datancontext
- /// </summary>
- protected readonly DataContext _dataContext;
-
- /// <summary>
- /// Initializes a new instance of the <see cref="QueryProvider<T>"/> class.
- /// </summary>
- /// <param name="dataContext">The data context.</param>
- public QueryProvider(DataContext dataContext)
- {
- _dataContext = dataContext;
- TableType = typeof(T);
- ExpressionChain = new ExpressionChain();
- }
-
- /// <summary>
- /// Initializes a new instance of the <see cref="QueryProvider<T>"/> class.
- /// </summary>
- /// <param name="tableType">Type of the table.</param>
- /// <param name="dataContext">The data context.</param>
- /// <param name="expressionChain">The expression chain.</param>
- /// <param name="expression">The expression.</param>
- public QueryProvider(Type tableType, DataContext dataContext, ExpressionChain expressionChain, Expression expression)
- {
- _dataContext = dataContext;
- TableType = tableType;
- ExpressionChain = new ExpressionChain(expressionChain, expression);
- }
-
- /// <summary>
- /// Creates the query.
- /// </summary>
- /// <typeparam name="S"></typeparam>
- /// <param name="t">The t.</param>
- /// <param name="tableType">Type of the table.</param>
- /// <param name="dataContext">The data context.</param>
- /// <param name="expressionChain">The expression chain.</param>
- /// <param name="expression">The expression.</param>
- /// <returns></returns>
- protected S CreateQuery<S>(Type t, Type tableType, DataContext dataContext, ExpressionChain expressionChain, Expression expression)
- {
- // no way to work differently
- var typedQueryProviderType = typeof(QueryProvider<>).MakeGenericType(t);
- var queryProvider = (S)Activator.CreateInstance(typedQueryProviderType, tableType, dataContext,
- expressionChain, expression);
- return queryProvider;
- }
-
- /// <summary>
- /// Builds the query, given a LINQ expression
- /// </summary>
- /// <param name="expression"></param>
- /// <returns></returns>
- public IQueryable CreateQuery(Expression expression)
- {
- var type = expression.Type;
- if (!type.IsGenericType)
- throw Error.BadArgument("S0066: Don't know how to handle non-generic type '{0}'", type);
- var genericType = type.GetGenericTypeDefinition();
- if (genericType == typeof(IQueryable<>) || genericType == typeof(IOrderedQueryable<>))
- type = type.GetGenericArguments()[0];
- else
- Error.BadArgument("S0068: Don't know how to handle type '{0}'", type);
- return CreateQuery<IQueryable>(type, TableType, _dataContext, ExpressionChain, expression);
- }
-
- /// <summary>
- /// Creates the query.
- /// </summary>
- /// <typeparam name="TElement">The type of the element.</typeparam>
- /// <param name="expression">The expression.</param>
- /// <returns></returns>
- public IQueryable<TElement> CreateQuery<TElement>(Expression expression)
- {
- Profiler.At("START QueryProvider.CreateQuery<{0}>({1})", typeof(TElement).Name, expression.ToString());
- var query = new QueryProvider<TElement>(TableType, _dataContext, ExpressionChain, expression);
- Profiler.At("END QueryProvider.CreateQuery<{0}>(...)", typeof(TElement).Name);
- return query;
- }
-
- /// <summary>
- /// Gets the query.
- /// </summary>
- /// <param name="expression">The expression.</param>
- /// <returns></returns>
- public override SelectQuery GetQuery(Expression expression)
- {
- var expressionChain = ExpressionChain;
- if (expression != null)
- expressionChain = new ExpressionChain(expressionChain, expression);
- return _dataContext.QueryBuilder.GetSelectQuery(expressionChain, new QueryContext(_dataContext));
- }
-
- /// <summary>
- /// Runs query
- /// </summary>
- /// <param name="expression"></param>
- /// <returns></returns>
- public object Execute(Expression expression)
- {
- return this.GetType()
- .GetMethods()
- .Where(m => m.Name == "Execute" && m.IsGenericMethod)
- .Single()
- .MakeGenericMethod(new Type[] { expression.Type })
- .Invoke(this, new object[] { expression });
- }
-
- /// <summary>
- /// Runs query
- /// </summary>
- /// <typeparam name="TResult"></typeparam>
- /// <param name="expression"></param>
- /// <returns></returns>
- public TResult Execute<TResult>(Expression expression)
- {
- Profiler.At("START QueryProvider.Execute<{0}>(): Executing expression...", typeof(TResult).Name);
- var query = GetQuery(expression);
- var result = _dataContext.QueryRunner.SelectScalar<TResult>(query);
- Profiler.At("END QueryProvider.Execute<{0}>(): Executing expression...", typeof(TResult).Name);
- return result;
- }
-
- /// <summary>
- /// Enumerates all query items
- /// </summary>
- /// <returns></returns>
- IEnumerator IEnumerable.GetEnumerator()
- {
- var enumerator = GetEnumerator();
- return enumerator;
- }
-
- /// <summary>
- /// Enumerates all query items
- /// </summary>
- /// <returns></returns>
- public IEnumerator<T> GetEnumerator()
- {
- Profiler.At("START QueryProvider.GetEnumerator<{0}>(): Executing expression...", typeof(T).Name);
- var query = GetQuery(null);
- var enumerator = _dataContext.QueryRunner.Select<T>(query).GetEnumerator();
- Profiler.At("END QueryProvider.GetEnumerator<{0}>(): Executing expression...", typeof(T).Name);
- return enumerator;
- }
-
- /// <summary>
- /// Returns this QueryProvider as an exception
- /// </summary>
- public Expression Expression
- {
- get { return Expression.Constant(this); }
- }
-
- public Type ElementType
- {
- get { return (typeof(T)); }
- }
-
- public IQueryProvider Provider
- {
- get { return this; }
- }
- }
- }