private IDictionary <string, SlaveToken> GetSlaves(IStatementBase statement, IDataReader reader)
{
IEnumerable <ParameterToken> GetParameters(string path)
{
if (string.IsNullOrEmpty(path))
{
yield break;
}
for (int i = 0; i < reader.FieldCount; i++)
{
var name = reader.GetName(i);
if (name.StartsWith("$" + path + ":"))
{
yield return(new ParameterToken(name.Substring(path.Length + 2), i));
}
}
}
if (statement.HasSlaves)
{
var tokens = new Dictionary <string, SlaveToken>(statement.Slaves.Count);
foreach (var slave in statement.Slaves)
{
if (slave is SelectStatementBase selection && !string.IsNullOrEmpty(selection.Alias))
{
var schema = _context.Schema.Find(selection.Alias);
if (schema != null)
{
tokens.Add(selection.Alias, new SlaveToken(schema, GetParameters(selection.Alias)));
}
}
}
if (tokens.Count > 0)
{
return(tokens);
}
}
return(null);
}
protected override void VisitStatement(ExpressionVisitorContext context, IStatementBase statement)
{
switch (statement)
{
case TableDefinition table:
MySqlTableDefinitionVisitor.Instance.Visit(context, table);
break;
case SelectStatement select:
MySqlSelectStatementVisitor.Instance.Visit(context, select);
break;
case DeleteStatement delete:
MySqlDeleteStatementVisitor.Instance.Visit(context, delete);
break;
case InsertStatement insert:
MySqlInsertStatementVisitor.Instance.Visit(context, insert);
break;
case UpdateStatement update:
MySqlUpdateStatementVisitor.Instance.Visit(context, update);
break;
case UpsertStatement upsert:
MySqlUpsertStatementVisitor.Instance.Visit(context, upsert);
break;
case AggregateStatement aggregate:
MySqlAggregateStatementVisitor.Instance.Visit(context, aggregate);
break;
case ExistStatement exist:
MySqlExistStatementVisitor.Instance.Visit(context, exist);
break;
case ExecutionStatement execution:
MySqlExecutionStatementVisitor.Instance.Visit(context, execution);
break;
default:
throw new DataException($"Not supported '{statement}' statement.");
}
}
protected override IExpression VisitStatement(IStatementBase statement)
{
switch (statement)
{
case TableDefinition table:
MsSqlTableDefinitionVisitor.Instance.Visit(this, table);
break;
case SelectStatement select:
MsSqlSelectStatementVisitor.Instance.Visit(this, select);
break;
case DeleteStatement delete:
MsSqlDeleteStatementVisitor.Instance.Visit(this, delete);
break;
case InsertStatement insert:
MsSqlInsertStatementVisitor.Instance.Visit(this, insert);
break;
case UpdateStatement update:
MsSqlUpdateStatementVisitor.Instance.Visit(this, update);
break;
case UpsertStatement upsert:
MsSqlUpsertStatementVisitor.Instance.Visit(this, upsert);
break;
case AggregateStatement aggregate:
MsSqlAggregateStatementVisitor.Instance.Visit(this, aggregate);
break;
case ExistStatement exist:
MsSqlExistStatementVisitor.Instance.Visit(this, exist);
break;
case ExecutionStatement execution:
MsSqlExecutionStatementVisitor.Instance.Visit(this, execution);
break;
}
return(statement);
}
//public override IExpressionDialect Dialect => DummyDialect.Instance;
#endregion
#region 重写方法
protected override IExpression VisitStatement(IStatementBase statement)
{
switch (statement)
{
case TableDefinition table:
DummyTableDefinitionVisitor.Instance.Visit(this, table);
break;
case CountStatement count:
DummyCountStatementVisitor.Instance.Visit(this, count);
break;
case ExistStatement exist:
DummyExistStatementVisitor.Instance.Visit(this, exist);
break;
case ExecutionStatement execution:
DummyExecutionStatementVisitor.Instance.Visit(this, execution);
break;
case SelectStatement select:
DummySelectStatementVisitor.Instance.Visit(this, select);
break;
case DeleteStatement delete:
DummyDeleteStatementVisitor.Instance.Visit(this, delete);
break;
case InsertStatement insert:
DummyInsertStatementVisitor.Instance.Visit(this, insert);
break;
case UpdateStatement update:
DummyUpdateStatementVisitor.Instance.Visit(this, update);
break;
case UpsertStatement upsert:
DummyUpsertStatementVisitor.Instance.Visit(this, upsert);
break;
}
return(statement);
}
public void Execute(IDataAccessContext context, IStatementBase statement)
{
switch (statement)
{
case SelectStatement select:
_select.Execute(context, select);
break;
case DeleteStatement delete:
_delete.Execute(context, delete);
break;
case InsertStatement insert:
_insert.Execute(context, insert);
break;
case UpdateStatement update:
_update.Execute(context, update);
break;
case UpsertStatement upsert:
_upsert.Execute(context, upsert);
break;
case CountStatement count:
_count.Execute(context, count);
break;
case ExistStatement exist:
_exist.Execute(context, exist);
break;
case ExecutionStatement execution:
_execution.Execute(context, execution);
break;
default:
context.Session.Build(statement).ExecuteNonQuery();
break;
}
}
private void BuildUpsertion(DataUpdateContext context, object data, IStatementBase master, SchemaMember schema)
{
var entityType = schema.Parent == null ? context.EntityType : schema.Parent.Token.MemberType;
//构建 Upsert 操作上下文
var upsert = new DataUpsertContext(
context.DataAccess,
schema.Token.Property.Entity.Name,
true,
data,
new Schema(schema.Token.Property.Entity, entityType, schema),
context.HasStates ? context.States : null);
//构建 Upsert 语句
var statements = context.Source.Driver.Builder.Build(upsert);
//将新建的语句加入到主语句的从属集中
foreach (var statement in statements)
{
master.Slaves.Add(statement);
}
}
protected abstract void VisitStatement(ExpressionVisitorContext context, IStatementBase statement);
protected virtual IExpression VisitStatement(IStatementBase statement)
{
return(statement);
}
protected abstract IExpression GetValue(TContext context, IStatementBase statement, object value);
protected abstract IExpression GetField(TContext context, IStatementBase statement, string name);
private IExpression GenerateAggregate(TContext context, IStatementBase statement, Operand.AggregateOperand aggregate)
{
var entity = this.GetEntity(context);
SelectStatement selection;
IDataEntityProperty property;
FieldIdentifier field;
var parts = aggregate.Member.Split('.', StringSplitOptions.RemoveEmptyEntries);
switch (parts.Length)
{
case 1:
if (!entity.Properties.TryGet(parts[0], out property))
{
throw new DataException($"The specified '{parts[0]}' field does not exist in the '{entity.Name}' entity.");
}
selection = new SelectStatement(entity);
field = selection.Table.CreateField(property);
selection.Select.Members.Add(new AggregateExpression(aggregate.Function, aggregate.Distinct, field));
break;
case 2:
if (!entity.Properties.TryGet(parts[0], out property))
{
throw new DataException($"The specified '{parts[0]}' field does not exist in the '{entity.Name}' entity.");
}
if (property.IsSimplex)
{
throw new DataException($"The specified '{parts[0]}' is a simple property and cannot be navigated.");
}
var complex = (IDataEntityComplexProperty)property;
selection = new SelectStatement(complex.Foreign);
field = selection.Table.CreateField(complex.Foreign.Properties.Get(parts[1]));
selection.Select.Members.Add(new AggregateExpression(aggregate.Function, aggregate.Distinct, field));
var conditions = ConditionExpression.And();
foreach (var link in complex.Links)
{
ISource src = statement.Table;
foreach (var anchor in link.GetAnchors())
{
if (anchor.IsComplex)
{
src = selection.Join(context.Aliaser, selection, (IDataEntityComplexProperty)anchor);
}
else
{
conditions.Add(Expression.Equal(
selection.Table.CreateField(link.ForeignKey),
src.CreateField(anchor)));
}
}
}
selection.Where = conditions;
break;
default:
throw new DataException($"Invalid aggregate member ‘{aggregate.Member}’ because its navigation level is too deep.");
}
if (aggregate.Filter != null)
{
if (selection.Where == null)
{
selection.Where = selection.Where(aggregate.Filter.Flatten(), context.Aliaser);
}
else
{
selection.Where = ConditionExpression.And(selection.Where, selection.Where(aggregate.Filter.Flatten(), context.Aliaser));
}
}
selection.Table.Alias = null;
return(selection);
}
public SubqueryStatement(IStatementBase host, Metadata.IDataEntity entity) : base(new TableIdentifier(entity))
{
this.Host = host ?? throw new ArgumentNullException(nameof(host));
}
public SubqueryStatement(IStatementBase host, TableIdentifier table) : base(table)
{
this.Host = host ?? throw new ArgumentNullException(nameof(host));
}
