protected override IBuildContext BuildMethodCall(ExpressionBuilder builder, MethodCallExpression methodCall, BuildInfo buildInfo)
{
var deleteType = methodCall.Method.Name switch
{
nameof(LinqExtensions.DeleteWithOutput) => DeleteContext.DeleteType.DeleteOutput,
nameof(LinqExtensions.DeleteWithOutputInto) => DeleteContext.DeleteType.DeleteOutputInto,
_ => DeleteContext.DeleteType.Delete,
};
var sequence = builder.BuildSequence(new BuildInfo(buildInfo, methodCall.Arguments[0]));
if (methodCall.Arguments.Count == 2 && deleteType == DeleteContext.DeleteType.Delete)
{
sequence = builder.BuildWhere(buildInfo.Parent, sequence, (LambdaExpression)methodCall.Arguments[1].Unwrap(), false);
}
var deleteStatement = new SqlDeleteStatement(sequence.SelectQuery);
sequence.Statement = deleteStatement;
// Check association.
//
if (sequence is SelectContext ctx && ctx.IsScalar)
{
var res = ctx.IsExpression(null, 0, RequestFor.Association);
if (res.Result)
{
var isTableResult = res.Context !.IsExpression(null, 0, RequestFor.Table);
if (!isTableResult.Result)
{
throw new LinqException("Can not retrieve Table context from association.");
}
var atc = (TableBuilder.TableContext)isTableResult.Context !;
deleteStatement.Table = atc.SqlTable;
}
else
{
res = ctx.IsExpression(null, 0, RequestFor.Table);
if (res.Result && res.Context is TableBuilder.TableContext context)
{
var tc = context;
if (deleteStatement.SelectQuery.From.Tables.Count == 0 || deleteStatement.SelectQuery.From.Tables[0].Source != tc.SelectQuery)
{
deleteStatement.Table = tc.SqlTable;
}
}
}
}
var indexedParameters
= methodCall.Method.GetParameters().Select((p, i) => Tuple.Create(p, i)).ToDictionary(t => t.Item1.Name, t => t.Item2);
Expression GetArgumentByName(string name)
{
return(methodCall.Arguments[indexedParameters[name]]);
}
LambdaExpression GetOutputExpression(Type outputType)
{
if (!indexedParameters.TryGetValue("outputExpression", out var index))
{
var param = Expression.Parameter(outputType);
return(Expression.Lambda(param, param));
}
return((LambdaExpression)methodCall.Arguments[index].Unwrap());
}
IBuildContext? outputContext = null;
LambdaExpression?outputExpression = null;
if (deleteType != DeleteContext.DeleteType.Delete)
{
outputExpression = GetOutputExpression(methodCall.Method.GetGenericArguments().Last());
deleteStatement.Output = new SqlOutputClause();
var deletedTable = SqlTable.Deleted(methodCall.Method.GetGenericArguments()[0]);
outputContext = new TableBuilder.TableContext(builder, new SelectQuery(), deletedTable);
deleteStatement.Output.DeletedTable = deletedTable;
if (deleteType == DeleteContext.DeleteType.DeleteOutputInto)
{
var outputTable = GetArgumentByName("outputTable");
var destination = builder.BuildSequence(new BuildInfo(buildInfo, outputTable, new SelectQuery()));
UpdateBuilder.BuildSetter(
builder,
buildInfo,
outputExpression,
destination,
deleteStatement.Output.OutputItems,
outputContext);
deleteStatement.Output.OutputTable = ((TableBuilder.TableContext)destination).SqlTable;
}
}
if (deleteType == DeleteContext.DeleteType.DeleteOutput)
{
return(new DeleteWithOutputContext(buildInfo.Parent, sequence, outputContext !, outputExpression !));
}
return(new DeleteContext(buildInfo.Parent, sequence));
}
protected override IBuildContext BuildMethodCall(ExpressionBuilder builder, MethodCallExpression methodCall, BuildInfo buildInfo)
{
var mergeContext = (MergeContext)builder.BuildSequence(new BuildInfo(buildInfo, methodCall.Arguments[0]));
var kind = MergeKind.Merge;
if (methodCall.IsSameGenericMethod(MergeWithOutputInto))
{
kind = MergeKind.MergeWithOutputInto;
}
else if (methodCall.IsSameGenericMethod(MergeWithOutput))
{
kind = MergeKind.MergeWithOutput;
}
if (kind != MergeKind.Merge)
{
var objectType = methodCall.Method.GetGenericArguments()[0];
var actionField = SqlField.FakeField(new DbDataType(typeof(string)), "$action", false);
var insertedTable = SqlTable.Inserted(objectType);
var deletedTable = SqlTable.Deleted(objectType);
mergeContext.Merge.Output = new SqlOutputClause()
{
InsertedTable = insertedTable,
DeletedTable = deletedTable,
};
var selectQuery = new SelectQuery();
var actionFieldContext = new SingleExpressionContext(null, builder, actionField, selectQuery);
var deletedTableContext = new TableBuilder.TableContext(builder, selectQuery, deletedTable);
var insertedTableConext = new TableBuilder.TableContext(builder, selectQuery, insertedTable);
if (kind == MergeKind.MergeWithOutput)
{
var outputExpression = (LambdaExpression)methodCall.Arguments[1].Unwrap();
var outputContext = new MergeOutputContext(
buildInfo.Parent,
outputExpression,
mergeContext,
actionFieldContext,
deletedTableContext,
insertedTableConext
);
return(outputContext);
}
else
{
var outputExpression = (LambdaExpression)methodCall.Arguments[2].Unwrap();
var outputTable = methodCall.Arguments[1];
var destination = builder.BuildSequence(new BuildInfo(buildInfo, outputTable, new SelectQuery()));
UpdateBuilder.BuildSetterWithContext(
builder,
buildInfo,
outputExpression,
destination,
mergeContext.Merge.Output.OutputItems,
actionFieldContext,
deletedTableContext,
insertedTableConext
);
mergeContext.Merge.Output.OutputTable = ((TableBuilder.TableContext)destination).SqlTable;
}
}
return(mergeContext);
}