protected DeclarationCommand UpdateDeclaration(DeclarationCommand decl, IEnumerable <VariableDeclaration> variables, SelectExpression source)
{
if (variables != decl.Variables || source != decl.Source)
{
return(new DeclarationCommand(variables, source));
}
return(decl);
}
// make a variable declaration / initialization for dependent generated values
private CommandExpression GetDependentGeneratedVariableDeclaration(MappingEntity entity, MappingTable table, List <MemberInfo> members, Expression instance, Dictionary <MemberInfo, Expression> map)
{
// first make command that retrieves the generated ids if any
DeclarationCommand genIdCommand = null;
var generatedIds = this.mapping.GetMappedMembers(entity).Where(m => this.mapping.IsPrimaryKey(entity, m) && this.mapping.IsGenerated(entity, m)).ToList();
if (generatedIds.Count > 0)
{
genIdCommand = this.GetGeneratedIdCommand(entity, members, map);
// if that's all there is then just return the generated ids
if (members.Count == generatedIds.Count)
{
return(genIdCommand);
}
}
// next make command that retrieves the generated members
// only consider members that were not generated ids
members = members.Except(generatedIds).ToList();
var tableAlias = new TableAlias();
var tex = new TableExpression(tableAlias, entity, this.mapping.GetTableName(table));
Expression where = null;
if (generatedIds.Count > 0)
{
where = generatedIds.Select((m, i) =>
this.GetMemberExpression(tex, entity, m).Equal(map[m])
).Aggregate((x, y) => x.And(y));
}
else
{
where = this.GetIdentityCheck(tex, entity, instance);
}
TableAlias selectAlias = new TableAlias();
var columns = new List <ColumnDeclaration>();
var variables = new List <VariableDeclaration>();
foreach (var mi in members)
{
ColumnExpression col = (ColumnExpression)this.GetMemberExpression(tex, entity, mi);
columns.Add(new ColumnDeclaration(this.mapping.GetColumnName(entity, mi), col, col.QueryType));
ColumnExpression vcol = new ColumnExpression(col.Type, col.QueryType, selectAlias, col.Name);
variables.Add(new VariableDeclaration(mi.Name, col.QueryType, vcol));
map.Add(mi, new VariableExpression(mi.Name, col.Type, col.QueryType));
}
var genMembersCommand = new DeclarationCommand(variables, new SelectExpression(selectAlias, columns, tex, where));
if (genIdCommand != null)
{
return(new BlockCommand(genIdCommand, genMembersCommand));
}
return(genMembersCommand);
}
protected override Expression VisitDeclaration(DeclarationCommand decl)
{
if (decl.Source != null)
{
// make query that returns all these declared values as an object[]
var projection = new ProjectionExpression(
decl.Source,
Expression.NewArrayInit(
typeof(object),
decl.Variables.Select(v => v.Expression.Type.IsValueType
? Expression.Convert(v.Expression, typeof(object))
: v.Expression).ToArray()
),
Aggregator.GetAggregator(typeof(object[]), typeof(IEnumerable <object[]>))
);
// create execution variable to hold the array of declared variables
var vars = Expression.Parameter(typeof(object[]), "vars");
this.variables.Add(vars);
this.initializers.Add(Expression.Constant(null, typeof(object[])));
// create subsitution for each variable (so it will find the variable value in the new vars array)
for (int i = 0, n = decl.Variables.Count; i < n; i++)
{
var v = decl.Variables[i];
NamedValueExpression nv = new NamedValueExpression(
v.Name, v.QueryType,
Expression.Convert(Expression.ArrayIndex(vars, Expression.Constant(i)), v.Expression.Type)
);
this.variableMap.Add(v.Name, nv);
}
// make sure the execution of the select stuffs the results into the new vars array
return(MakeAssign(vars, this.Visit(projection)));
}
// probably bad if we get here since we must not allow mulitple commands
throw new InvalidOperationException("Declaration query not allowed for this langauge");
}
protected override Expression VisitDeclaration(DeclarationCommand decl)
{
throw new NotSupportedException();
}
protected virtual Expression GetInsertResult(MappingEntity entity, Expression instance, LambdaExpression selector, Dictionary <MemberInfo, Expression> map)
{
var tableAlias = new TableAlias();
var tex = new TableExpression(tableAlias, entity, this.mapping.GetTableName(entity));
var aggregator = Aggregator.GetAggregator(selector.Body.Type, typeof(IEnumerable <>).MakeGenericType(selector.Body.Type));
Expression where;
DeclarationCommand genIdCommand = null;
var generatedIds = this.mapping.GetMappedMembers(entity).Where(m => this.mapping.IsPrimaryKey(entity, m) && this.mapping.IsGenerated(entity, m)).ToList();
if (generatedIds.Count > 0)
{
if (map == null || !generatedIds.Any(m => map.ContainsKey(m)))
{
var localMap = new Dictionary <MemberInfo, Expression>();
genIdCommand = this.GetGeneratedIdCommand(entity, generatedIds.ToList(), localMap);
map = localMap;
}
// is this just a retrieval of one generated id member?
var mex = selector.Body as MemberExpression;
if (mex != null && this.mapping.IsPrimaryKey(entity, mex.Member) && this.mapping.IsGenerated(entity, mex.Member))
{
if (genIdCommand != null)
{
// just use the select from the genIdCommand
return(new ProjectionExpression(
genIdCommand.Source,
new ColumnExpression(mex.Type, genIdCommand.Variables[0].QueryType, genIdCommand.Source.Alias, genIdCommand.Source.Columns[0].Name),
aggregator
));
}
else
{
TableAlias alias = new TableAlias();
var colType = this.GetColumnType(entity, mex.Member);
return(new ProjectionExpression(
new SelectExpression(alias, new[] { new ColumnDeclaration("", map[mex.Member], colType) }, null, null),
new ColumnExpression(TypeHelper.GetMemberType(mex.Member), colType, alias, ""),
aggregator
));
}
}
where = generatedIds.Select((m, i) =>
this.GetMemberExpression(tex, entity, m).Equal(map[m])
).Aggregate((x, y) => x.And(y));
}
else
{
where = this.GetIdentityCheck(tex, entity, instance);
}
Expression typeProjector = this.GetEntityExpression(tex, entity);
Expression selection = DbExpressionReplacer.Replace(selector.Body, selector.Parameters[0], typeProjector);
TableAlias newAlias = new TableAlias();
var pc = ColumnProjector.ProjectColumns(this.translator.Linguist.Language, selection, null, newAlias, tableAlias);
var pe = new ProjectionExpression(
new SelectExpression(newAlias, pc.Columns, tex, where),
pc.Projector,
aggregator
);
if (genIdCommand != null)
{
return(new BlockCommand(genIdCommand, pe));
}
return(pe);
}
