Tutorial_04_DictionaryPool()
{
//----------------------------------------------------------------------------------------------------------
// Create a Stash Client for the Employee class
StashClient <Employee>
clientEmployee = StashConfiguration.GetClient <Employee>();
clientEmployee.CreateTableIfNotExist();
//----------------------------------------------------------------------------------------------------------
// Create an StashClient for the generic pool class,
// Since we want to read and write to the Employee table, notice how we setup the correct EntityName in
// the StashClientOptions. Otherwise the azure table implied would be "GenericPool".
//
// The call back method of naming the table has flexible capabilities. It can be used to determine
// the table name dynamically based on the data in the object instance.
// In this case it is used statically and called only once.
StashClient <GenericPool>
clientGenericPool = StashConfiguration.GetClient <GenericPool>(
new StashClientOptions {
OverrideEntitySetName = o => "Employee",
OverrideEntitySetNameIsDynamic = false,
Feedback = StashConfiguration.TraceFeedback,
});
//----------------------------------------------------------------------------------------------------------
// Stash an Employee
const
string departmentDev = "Dev";
Employee
dataEmployee = new Employee {
Department = departmentDev,
EmployeeId = Guid.NewGuid().ToString(),
Name = "John Doe",
SkillLevel = 8,
DateOfBirth = new DateTime(1990, 1, 1)
};
dataEmployee.SetAnnualSalary();
clientEmployee.Insert(dataEmployee);
//----------------------------------------------------------------------------------------------------------
// and read it back thru the GenericPool
GenericPool
dataPool = clientGenericPool.Get(
dataEmployee.Department,
dataEmployee.EmployeeId);
//----------------------------------------------------------------------------------------------------------
// Verify we got back what we put in via the Employee type.
Assert.IsTrue(
dataPool.PrimaryKey == dataEmployee.Department &&
dataPool.SecondaryKey == dataEmployee.EmployeeId &&
dataPool.Pool["AnnualSalary"].Equals(dataEmployee.GetAnnualSalary()) &&
dataPool.Pool["Birthday"].Equals(dataEmployee.DateOfBirth) &&
dataPool.Pool["SkillLevel"].Equals(dataEmployee.SkillLevel) &&
dataPool.Pool["Name"].Equals(dataEmployee.Name) &&
dataPool.Pool.Count == 4 + 1); // + 1 to the ETag
//----------------------------------------------------------------------------------------------------------
// Make a few changes and update
dataPool.Pool["Name"] = "Lucifure"; // name change
dataPool.Pool["Unique"] = Guid.NewGuid(); // new field
clientGenericPool.Update(dataPool);
// Note: Updates, Merges etc keep the original objects in sync with the latest ETags.
// Even if an ETag is not specified for the type, if the type supports a Pool,
// the ETag is maintained and synched in the pool
//----------------------------------------------------------------------------------------------------------
// Read back the data
GenericPool
dataPoolRead = clientGenericPool.CreateQuery()
.Where(imp => imp.PrimaryKey == dataEmployee.Department &&
imp.SecondaryKey == dataEmployee.EmployeeId)
.FirstOrDefault();
//----------------------------------------------------------------------------------------------------------
// and verify that we got back what we put in
Assert.IsTrue(
dataPool.PrimaryKey == dataPoolRead.PrimaryKey &&
dataPool.SecondaryKey == dataPoolRead.SecondaryKey &&
StashHelper.DictionaryEquals(
dataPool.Pool,
dataPoolRead.Pool));
//----------------------------------------------------------------------------------------------------------
// Merge can be performed very efficiently with a StashPool. Only include the tables properties
// to be merge in the dictionary. No need to null out members or defined nullable value type members.
// Create a new pool with just the objects of interest
Dictionary <string, object>
pool = new Dictionary <string, object>();
// save the current etag (for now and later)
string
etagPreMerge = dataPoolRead.Pool[Literal.ETag].ToString();
pool["Name"] = "Stash"; // new value to merge
pool[Literal.ETag] = etagPreMerge; // get the ETag too
// create a new pool object for merging.
GenericPool
dataPoolMerged = new GenericPool {
PrimaryKey = dataPoolRead.PrimaryKey,
SecondaryKey = dataPoolRead.SecondaryKey,
Pool = pool
};
clientGenericPool.Merge(dataPoolMerged, ETagMatch.Must); // force ETag matching.
// read back and verify
GenericPool
dataPoolMergedRead = clientGenericPool.Get(
dataPoolMerged.PrimaryKey,
dataPoolMerged.SecondaryKey);
// validate
Assert.IsTrue(dataPoolMergedRead.Pool.Count == dataPoolRead.Pool.Count &&
dataPoolMergedRead.Pool["Name"] as String == "Stash");
//----------------------------------------------------------------------------------------------------------
// attempt to merge again, replacing the current ETag with the old one.
bool isSuccess;
try
{
// use the defunct etag to exhibit this
dataPoolMerged.Pool[Literal.ETag] = etagPreMerge;
clientGenericPool.Merge(dataPoolMerged);
isSuccess = false;
}
catch (Exception ex)
{
// Merge fails because the ETag was old and did not match.
Assert.IsTrue((ex as StashException).Error == StashError.ETagMatchFailed);
isSuccess = true;
}
Assert.IsTrue(isSuccess);
//----------------------------------------------------------------------------------------------------------
// attempt to merge yet again, this time by disabling ETag matching.
clientGenericPool.Merge(dataPoolMerged, ETagMatch.Unconditional);
//----------------------------------------------------------------------------------------------------------
// now attempt to delete the entity
try
{
clientGenericPool.Delete(dataPoolMergedRead); // Implicit ETag matching, will make this fail too
// because the last update changed the ETag
isSuccess = false;
}
catch (Exception ex)
{
Assert.IsTrue((ex as StashException).Error == StashError.ETagMatchFailed);
isSuccess = true;
}
Assert.IsTrue(isSuccess);
//----------------------------------------------------------------------------------------------------------
// Do an unconditional delete
clientGenericPool.DeleteUnconditional(dataPoolMergedRead);
//----------------------------------------------------------------------------------------------------------
// And verify that it was actually deleted
// by attempting to read back the data
var queryable = from emp in clientEmployee.CreateQuery()
where emp.Department == dataEmployee.Department &&
emp.EmployeeId == dataEmployee.EmployeeId
select emp;
Assert.IsTrue(queryable.ToList().Count == 0);
//----------------------------------------------------------------------------------------------------------
// So far so good. This concludes this part of the tutorial. Go Stash!
}