/// <summary>
/// 生成DbContext
/// </summary>
private static void GenerationDContext(string contextProjectName, string contextPath, string savePath, List <string> tables, string classNamespace)
{
var templatePath = Methods.GetCurrentProjectPath + "\\Template\\DbContext.txt";//dbcontexts模版文件
//下面代码不动
var model = new DbContextParameter
{
ConnectionString = connectionString,
DbType = dbType,
Tables = tables,
ClassNamespace = classNamespace
};
Methods.CreateDbContext(templatePath, savePath, model);
AddTask(contextProjectName, contextPath);
}
public Expression CreateQueryExpression(Type elementType, DbContext context)
{
var targetType = context.Model.GetEntityTypes().SingleOrDefault(t => t.ClrType == elementType);
Expression queryExpression;
if (targetType.DefiningQuery != null)
{
queryExpression = targetType.DefiningQuery.Body;
goto ApplyQueryFilters;
}
var rootType = targetType.RootType();
var schemaName = rootType.Relational().Schema ?? context.Model.Relational().DefaultSchema;
var tableName = rootType.Relational().TableName;
var table
= new BaseTableExpression(
schemaName,
tableName,
tableName.Substring(0, 1).ToLower(),
rootType.ClrType);
var materializer = CreateMaterializer(targetType, table);
var projection = new ServerProjectionExpression(materializer);
var selectExpression = new SelectExpression(projection, table);
var discriminatingType = targetType;
while (discriminatingType != null)
{
var discriminatorProperty = discriminatingType.Relational().DiscriminatorProperty;
if (discriminatorProperty != null)
{
selectExpression
= selectExpression.AddToPredicate(
new SqlInExpression(
MakeColumnExpression(
table,
discriminatorProperty),
Expression.NewArrayInit(
discriminatorProperty.ClrType,
from t in discriminatingType.GetDerivedTypesInclusive()
where !t.IsAbstract()
select Expression.Constant(
t.Relational().DiscriminatorValue,
discriminatorProperty.ClrType))));
}
discriminatingType = FindSameTabledPrincipalType(discriminatingType);
}
queryExpression = new EnumerableRelationalQueryExpression(selectExpression);
ApplyQueryFilters:
var currentType = targetType;
var recast = false;
while (currentType != null)
{
if (currentType.QueryFilter != null)
{
var filterBody = currentType.QueryFilter.Body;
var repointer
= new QueryFilterRepointingExpressionVisitor(
DbContextParameter.GetInstance(context.GetType()));
filterBody = repointer.Visit(filterBody);
// Use a method call instead of adding to the SelectExpression
// so the rewriting visitors are guaranteed to get their hands on the
// filter.
queryExpression
= Expression.Call(
queryableWhereMethodInfo.MakeGenericMethod(currentType.ClrType),
queryExpression,
Expression.Quote(
Expression.Lambda(
new QueryFilterExpression(filterBody),
currentType.QueryFilter.Parameters)));
recast |= currentType != targetType;
}
currentType = currentType.BaseType;
}
if (recast)
{
queryExpression
= Expression.Call(
queryableCastMethodInfo.MakeGenericMethod(targetType.ClrType),
queryExpression);
}
return(queryExpression);
}
