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EntityFrameworkCore.Jet
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Initial support for Skip....Take. Take...Skip and Skip currently do not work properly

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7.0-servicing
Christopher Jolly 3 years ago
parent d7268307bc
commit 8c9dff5d36
3 changed files with 119 additions and 20 deletions
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54
src/EFCore.Jet.Data/JetCommand.cs
Unescape Escape View File

@ -17,11 +17,12 @@ namespace EntityFrameworkCore.Jet.Data
#endif
private JetConnection? _connection;
private JetTransaction? _transaction;
private int _outerSelectSkipEmulationViaDataReaderSkipCount;
private static readonly Regex _createProcedureExpression = new Regex(@"^\s*create\s*procedure\b", RegexOptions.IgnoreCase);
private static readonly Regex _topParameterRegularExpression = new Regex(@"(?<=(?:^|\s)select\s+top\s+)(?:@\w+|\?)(?=\s)", RegexOptions.IgnoreCase);
private static readonly Regex _topMultiParameterRegularExpression = new Regex(@"(?<=(?:^|\s)select\s+top\s+)(?'first'@\w+|\?)(\s)(\+)(\s+)(?'sec'@\w+|\?)", RegexOptions.IgnoreCase);
private static readonly Regex _outerSelectTopValueRegularExpression = new Regex(@"(?<=^\s*select\s+top\s+)\d+(?=\s)", RegexOptions.IgnoreCase);
private static readonly Regex _outerSelectSkipValueOrParameterRegularExpression = new Regex(@"(?<=^\s*select)\s+skip\s+(?<SkipValueOrParameter>@\w+|\?|\d+)(?=\s)", RegexOptions.IgnoreCase);
private static readonly Regex _selectRowCountRegularExpression = new Regex(@"^\s*select\s*@@rowcount\s*;?\s*$", RegexOptions.IgnoreCase);
@ -35,7 +36,7 @@ namespace EntityFrameworkCore.Jet.Data
_connection = source._connection;
_transaction = source._transaction;
InnerCommand = (DbCommand) ((ICloneable) source.InnerCommand).Clone();
InnerCommand = (DbCommand)((ICloneable)source.InnerCommand).Clone();
}
/// <summary>
@ -153,7 +154,7 @@ namespace EntityFrameworkCore.Jet.Data
protected override DbTransaction? DbTransaction
{
get => _transaction;
set => _transaction = (JetTransaction?) value;
set => _transaction = (JetTransaction?)value;
}
/// <summary>
@ -269,7 +270,7 @@ namespace EntityFrameworkCore.Jet.Data
}
FixupGlobalVariables();
if (!CheckExists(InnerCommand.CommandText, out var newCommandText))
return 0;
@ -344,7 +345,7 @@ namespace EntityFrameworkCore.Jet.Data
protected virtual IReadOnlyList<JetCommand> SplitCommands()
{
// At this point, all parameters have already been expanded.
var parser = new JetCommandParser(CommandText);
var commandDelimiters = parser.GetStateIndices(';');
var currentCommandStart = 0;
@ -360,7 +361,7 @@ namespace EntityFrameworkCore.Jet.Data
if (!string.IsNullOrEmpty(commandText))
{
var command = (JetCommand) ((ICloneable) this).Clone();
var command = (JetCommand)((ICloneable)this).Clone();
command.CommandText = commandText;
if (_createProcedureExpression.IsMatch(command.CommandText))
@ -375,7 +376,7 @@ namespace EntityFrameworkCore.Jet.Data
}
var parameterIndices = parser.GetStateIndices(
new[] {'@', '?'},
new[] { '@', '?' },
currentCommandStart,
commandDelimiter - currentCommandStart);
@ -434,7 +435,7 @@ namespace EntityFrameworkCore.Jet.Data
.Value;
bool hasRows;
using (var command = (JetCommand) ((ICloneable) this).Clone())
using (var command = (JetCommand)((ICloneable)this).Clone())
{
command.CommandText = sqlCheckCommand;
using (var reader = command.ExecuteReader())
@ -470,18 +471,18 @@ namespace EntityFrameworkCore.Jet.Data
protected virtual void FixupGlobalVariables()
{
var commandText = InnerCommand.CommandText;
commandText = FixupIdentity(commandText);
commandText = FixupRowCount(commandText);
InnerCommand.CommandText = commandText;
}
protected virtual string FixupIdentity(string commandText)
=> FixupGlobalVariablePlaceholder(
commandText, "@@identity", (outerCommand, placeholder) =>
{
var command = (DbCommand) ((ICloneable) outerCommand.InnerCommand).Clone();
var command = (DbCommand)((ICloneable)outerCommand.InnerCommand).Clone();
command.CommandText = $"SELECT {placeholder}";
command.Parameters.Clear();
@ -511,7 +512,7 @@ namespace EntityFrameworkCore.Jet.Data
newCommandText.Insert(globalVariableIndex, placeholderValue.Value);
}
}
return newCommandText.ToString();
}
@ -527,6 +528,21 @@ namespace EntityFrameworkCore.Jet.Data
var lastCommandText = InnerCommand.CommandText;
var commandText = lastCommandText;
var matchm = _topMultiParameterRegularExpression.Match(lastCommandText);
if (matchm.Success)
{
var first = matchm.Groups["first"];
var sec = matchm.Groups["sec"];
var sp = Convert.ToInt32(ExtractParameter(commandText, sec.Index, parameters).Value);
var fp = Convert.ToInt32(ExtractParameter(commandText, first.Index, parameters).Value);
var total = fp + sp;
commandText = _topMultiParameterRegularExpression.Replace(
lastCommandText,
match => total.ToString(),
1);
lastCommandText = commandText;
}
while ((commandText = _topParameterRegularExpression.Replace(
lastCommandText,
match => Convert.ToInt32(
@ -544,7 +560,7 @@ namespace EntityFrameworkCore.Jet.Data
InnerCommand.Parameters.AddRange(parameters.ToArray());
}
}
private void ModifyOuterSelectTopValueForOuterSelectSkipEmulationViaDataReader()
{
// We modify the TOP clause parameter of the outer most SELECT statement if a SKIP clause was also
@ -587,7 +603,7 @@ namespace EntityFrameworkCore.Jet.Data
var parameter = ExtractParameter(InnerCommand.CommandText, match.Index, parameters);
_outerSelectSkipEmulationViaDataReaderSkipCount = Convert.ToInt32(parameter.Value);
InnerCommand.Parameters.Clear();
InnerCommand.Parameters.AddRange(parameters.ToArray());
}
@ -598,11 +614,11 @@ namespace EntityFrameworkCore.Jet.Data
InnerCommand.CommandText = InnerCommand.CommandText.Remove(match.Index, match.Length);
}
protected virtual bool IsParameter(string fragment)
=> fragment.Equals("?") ||
fragment.Length >= 2 && fragment[0] == '@' && fragment[1] != '@';
protected virtual DbParameter ExtractParameter(string commandText, int count, List<DbParameter> parameters)
{
var indices = GetParameterIndices(commandText.Substring(0, count));
@ -685,7 +701,7 @@ namespace EntityFrameworkCore.Jet.Data
throw new InvalidOperationException($"Cannot find parameter with same name as parameter placeholder \"{placeholder.Name}\".");
}
var newParameter = (DbParameter) (parameter as ICloneable)?.Clone();
var newParameter = (DbParameter)(parameter as ICloneable)?.Clone();
if (newParameter == null)
{
@ -710,7 +726,7 @@ namespace EntityFrameworkCore.Jet.Data
throw new InvalidOperationException("Invalid parameter placeholder found.");
}
placeholders.Add(new ParameterPlaceholder {Index = index, Name = match.Value});
placeholders.Add(new ParameterPlaceholder { Index = index, Name = match.Value });
}
return placeholders.AsReadOnly();
@ -718,7 +734,7 @@ namespace EntityFrameworkCore.Jet.Data
protected virtual IReadOnlyList<int> GetParameterIndices(string sqlFragment)
=> new JetCommandParser(sqlFragment)
.GetStateIndices(new[] {'@', '?'});
.GetStateIndices(new[] { '@', '?' });
/// <summary>
/// Creates a prepared (or compiled) version of the command on the data source

75
src/EFCore.Jet/Query/Internal/JetQueryableMethodTranslatingExpressionVisitor.cs
Unescape Escape View File

@ -1,10 +1,16 @@
// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
using System;
using System.Collections.Generic;
using System.Linq;
using System.Linq.Expressions;
using System.Reflection;
using Microsoft.EntityFrameworkCore.Diagnostics;
using Microsoft.EntityFrameworkCore.Metadata;
using Microsoft.EntityFrameworkCore.Query;
using Microsoft.EntityFrameworkCore.Query.SqlExpressions;
using Microsoft.EntityFrameworkCore.Storage;
namespace EntityFrameworkCore.Jet.Query.Internal;
@ -62,4 +68,73 @@ public class JetQueryableMethodTranslatingExpressionVisitor : RelationalQueryabl
}
return base.TranslateLeftJoin(outer, inner, outerKeySelector, innerKeySelector, resultSelector);
}
protected override ShapedQueryExpression? TranslateSkip(ShapedQueryExpression source, Expression count)
{
var selectExpression = (SelectExpression)source.QueryExpression;
var translation = TranslateExpression(count);
if (translation == null)
{
return null;
}
if (selectExpression.Orderings.Count == 0)
{
//_queryCompilationContext.Logger.RowLimitingOperationWithoutOrderByWarning();
}
var clone = selectExpression.Clone();
var limit = clone.Limit;
if (limit != null)
{
var total = new SqlBinaryExpression(ExpressionType.Add, limit, translation, typeof(int),
RelationalTypeMapping.NullMapping);
selectExpression.ApplyLimit(total);
}
else
{
selectExpression.ApplyLimit(translation);
selectExpression.Tags.Add("DeepSkip");
}
selectExpression.ReverseOrderings();
selectExpression.ApplyLimit(translation);
selectExpression.ReverseOrderings();
return source;
}
protected override ShapedQueryExpression? TranslateTake(ShapedQueryExpression source, Expression count)
{
var selectExpression = (SelectExpression)source.QueryExpression;
var translation = TranslateExpression(count);
if (translation == null)
{
return null;
}
if (selectExpression.Tags.Contains("DeepSkip"))
{
var f1 = selectExpression.Tables.First(d => d is SelectExpression) as SelectExpression;
var f2 = f1?.Tables.First(d => d is SelectExpression) as SelectExpression;
var limit = f2?.Limit;
if (limit != null)
{
var total = new SqlBinaryExpression(ExpressionType.Add, limit, translation, typeof(int),
RelationalTypeMapping.NullMapping);
//var sp = (SqlParameterExpression)limit;
//var sp2 = (SqlParameterExpression)translation;
//var newparam = Expression.Parameter(typeof(int), sp.Name + sp2.Name);
//var sqlparam = typeof(SqlParameterExpression).GetTypeInfo().DeclaredConstructors.First().Invoke(new object[] { newparam, RelationalTypeMapping.NullMapping });
var tp = f2!.GetType().GetMember("Limit").First();
MethodInfo? dynMethod2 = f2.GetType().GetMethod("set_Limit",
BindingFlags.NonPublic | BindingFlags.Instance);
dynMethod2?.Invoke(f2, new object[] { total });
MethodInfo? dynMethod1 = f1!.GetType().GetMethod("set_Limit",
BindingFlags.NonPublic | BindingFlags.Instance);
dynMethod1?.Invoke(f1, new object[] { translation });
selectExpression.Tags.Remove("DeepSkip");
return source;
}
}
return base.TranslateTake(source, count);
}
}

10
src/EFCore.Jet/Query/Sql/Internal/JetQuerySqlGenerator.cs
Unescape Escape View File

@ -95,7 +95,15 @@ namespace EntityFrameworkCore.Jet.Query.Sql.Internal
Sql.Append("DISTINCT ");
}
GenerateTop(selectExpression);
if (selectExpression.Tags.Contains("DeepSkip"))
{
}
else
{
GenerateTop(selectExpression);
}
if (selectExpression.Projection.Any())
{

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