protected DbUpdateCommand UpdateUpdate(DbUpdateCommand update, DbTableExpression table, Expression where, IEnumerable <DbColumnAssignment> assignments)
{
if (table != update.Table || where != update.Where || assignments != update.Assignments)
{
return(new DbUpdateCommand(table, where, assignments));
}
return(update);
}
protected virtual Expression VisitUpdate(DbUpdateCommand update)
{
var table = this.Visit(update.Table) as DbTableExpression;
var where = this.Visit(update.Where);
var assignments = this.VisitColumnAssignments(update.Assignments);
return(this.UpdateUpdate(update, table, where, assignments));
}
public override Expression GetUpdateExpression(MappingEntity entity, Expression instance, LambdaExpression updateCheck, LambdaExpression selector, Expression exp)
{
var tableAlias = new TableAlias();
var table = new DbTableExpression(tableAlias, entity, this.mapping.GetTableName(entity));
var where = this.GetIdentityCheck(table, entity, instance);
if (updateCheck != null)
{
var typeProjector = this.GetEntityExpression(table, entity);
var pred = DbExpressionReplacer.Replace(updateCheck.Body, updateCheck.Parameters[0], typeProjector);
if (pred != null)
{
where = where.And(pred);
}
}
var assignments = this.GetColumnAssignments(table, instance, entity, (e, m) => this.mapping.IsUpdatable(e, m));
var update = new DbUpdateCommand(table, where, assignments);
if (selector != null)
{
return(new DbBlockCommand
(
update,
new DbIFCommand
(
this.translator.Linguist.Language.GetRowsAffectedExpression(update).GreaterThan(Expression.Constant(0)),
this.GetUpdateResult(entity, instance, selector),
exp
)
));
}
else if (exp != null)
{
return(new DbBlockCommand
(
update,
new DbIFCommand
(
this.translator.Linguist.Language.GetRowsAffectedExpression(update).LessThanOrEqual(Expression.Constant(0)),
exp,
null
)
));
}
else
{
return(update);
}
}
protected override Expression VisitUpdate(DbUpdateCommand update)
{
this.Write("UPDATE ");
this.WriteTableName(update.Table.Name);
this.WriteLine(Indentation.Same);
var saveHide = this.HideColumnAliases;
this.HideColumnAliases = true;
this.Write("SET ");
for (int i = 0, n = update.Assignments.Count; i < n; i++)
{
var ca = update.Assignments[i];
if (i > 0)
{
this.Write(", ");
}
this.Visit(ca.Column);
this.Write(" = ");
this.Visit(ca.Expression);
}
if (update.Where != null)
{
this.WriteLine(Indentation.Same);
this.Write("WHERE ");
this.VisitPredicate(update.Where);
}
this.HideColumnAliases = saveHide;
return(update);
}
protected virtual bool CompareUpdate(DbUpdateCommand x, DbUpdateCommand y)
{
return(this.Compare(x.Table, y.Table) && this.Compare(x.Where, y.Where) && this.CompareColumnAssignments(x.Assignments, y.Assignments));
}
protected override Expression VisitUpdate(DbUpdateCommand update)
{
return(this.BuildExecuteCommand(update));
}