public override JoinExpression GetJoinExpression()
{
var rightIdentifier = AliasIdentifierExpression;
var leftIdentifier = Left.AliasIdentifierExpression;
var onCondition = default(QueryExpression);
foreach (var columnPair in _joinColumnPairs)
{
var newCondition = QueryExpression.Compare(
QueryExpression.Column(columnPair.LeftColumnName, leftIdentifier),
ComparisonOperator.AreEqual,
QueryExpression.Column(columnPair.RightColumnName, rightIdentifier)
);
onCondition = QueryExpression.CombineConditions(onCondition, ConditionType.AndAlso, newCondition);
}
return(QueryExpression.Join(
QueryExpression.Alias(
Right.AliasIdentifierExpression, rightIdentifier.Identifier
),
onCondition,
JoinDirection.Left
));
}
public ExpressionResult Convert(MethodInfo methodInfo, MethodCallExpression node,
ExpressionConverter expressionConverter)
{
var expression = expressionConverter.Convert(node.Arguments[0]);
var alias = expressionConverter.Convert(node.Arguments[1]).QueryExpression as ValueExpression;
return(new ExpressionResult(
QueryExpression.Alias(expression.QueryExpression, (string)alias.Value),
expression.RequiredJoins
));
}
private DeferableInsert <T> Insert <TView>(IEntityView <TView> transcriber, TView entity)
where TView : class
{
var mapBackInsertId = _serverGeneratedPrimaryKey != null;
var generatePrimaryKey = _clientGeneratedPrimaryKey != null;
var insertBuilder = QueryBuilder.Insert(entity);
if (generatePrimaryKey)
{
var newId = Guid.NewGuid();
insertBuilder.Assignments.Set(_clientGeneratedPrimaryKey, newId);
AttemptWriteToObject(entity, newId, _clientGeneratedPrimaryKey, transcriber);
}
if (!mapBackInsertId)
{
return(new DeferableInsert <T>(
insertBuilder, _dataProvider
));
}
var primaryKeyIntersectedFields = transcriber.EntityToClassIntersection.IntersectedFields
.FirstOrDefault(q => q.LeftField == _serverGeneratedPrimaryKey);
if (primaryKeyIntersectedFields == null)
{
return(new DeferableInsert <T>(
insertBuilder, _dataProvider
));
}
return(new DeferableInsert <T>(
insertBuilder, _dataProvider,
QueryExpression.Select(
QueryExpression.Alias(QueryExpression.LastInsertIdFunction(), _serverGeneratedPrimaryKey.ProjectionAlias),
from: QueryExpression.Table(_entityModel.Table.TableName)
),
new MapLastIdResultProcessor <TView>(
entity, primaryKeyIntersectedFields
)
));
}
public virtual async Task Select_AliasValues()
{
using (var queryResult = await DataProvider.ExecuteReaderAsync(
QueryExpression.Select(
new[] {
QueryExpression.Alias(QueryExpression.Value(1), "int"),
QueryExpression.Alias(QueryExpression.Value("Hello World"), "str")
}
)))
{
Assert.IsTrue(queryResult.HasRows);
Assert.AreEqual("int", queryResult.GetName(0));
Assert.AreEqual("str", queryResult.GetName(1));
Assert.AreEqual(0, queryResult.GetOrdinal("int"));
Assert.AreEqual(1, queryResult.GetOrdinal("str"));
Assert.IsTrue(await queryResult.ReadAsync());
Assert.AreEqual(1, queryResult.GetInt32(0));
Assert.AreEqual("Hello World", queryResult.GetString(1));
}
}
public virtual async Task Select_FromSubSelect()
{
// some database engines require the subquery to be aliased
var subQueryAlias = QueryExpression.Alias(
QueryExpression.Select(
new[] { QueryExpression.Alias(QueryExpression.Value(1), "value") }
),
"subQuery"
);
using (var queryResult = await DataProvider.ExecuteReaderAsync(
QueryExpression.Select(
new[] { QueryExpression.All() },
from: subQueryAlias
)))
{
Assert.IsTrue(queryResult.HasRows);
Assert.IsTrue(await queryResult.ReadAsync());
Assert.AreEqual(1, queryResult.GetInt32(0));
}
}