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FIX | db_id returns null on Azure SQL Database. #1294

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Merged
merged 5 commits into from
May 27, 2022
Merged

FIX | db_id returns null on Azure SQL Database. #1294

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46c819f
db_id() issue.
JRahnama Sep 27, 2021
6e6c245
closed reader.
JRahnama Sep 27, 2021
c4fe6e8
commit
JRahnama Sep 27, 2021
a465102
review comments
JRahnama Sep 28, 2021
fdc9c45
Merge branch 'main' of https://github.com/dotnet/SqlClient into 1264
David-Engel May 27, 2022
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11 changes: 10 additions & 1 deletion src/Microsoft.Data.SqlClient/netcore/src/Microsoft/Data/SqlClient/SqlDependencyListener.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -90,6 +90,7 @@ internal SqlConnectionContainer(SqlConnectionContainerHashHelper hashHelper, str
_con.Open();

_cachedServer = _con.DataSource;
bool? dbId = null;

_escapedQueueName = SqlConnection.FixupDatabaseTransactionName(_queue); // Properly escape to prevent SQL Injection.
_appDomainKeyHash = new Dictionary<string, int>(); // Dictionary stores the Start/Stop refcount per AppDomain for this container.
Expand All @@ -100,7 +101,15 @@ internal SqlConnectionContainer(SqlConnectionContainerHashHelper hashHelper, str
CommandText = "select is_broker_enabled from sys.databases where database_id=db_id()"
};

if (!(bool)_com.ExecuteScalar())
// db_id() returns the database ID of the current database hence it will always be one line result
using SqlDataReader reader = _com.ExecuteReader(CommandBehavior.SingleRow);
if (reader.Read() && reader[0] is not null)
{
dbId = reader.GetBoolean(0);
}
reader.Close();

if (dbId is null || !dbId.Value)
{
throw SQL.SqlDependencyDatabaseBrokerDisabled();
}
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11 changes: 10 additions & 1 deletion src/Microsoft.Data.SqlClient/netfx/src/Microsoft/Data/SqlClient/SqlDependencyListener.cs
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Expand Up @@ -138,11 +138,20 @@ internal SqlConnectionContainer(SqlConnectionContainerHashHelper hashHelper, str
_appDomainKeyHash = new Dictionary<string, int>(); // Dictionary stores the Start/Stop refcount per AppDomain for this container.
_com = new SqlCommand();
_com.Connection = _con;
bool? dbId = null;

// SQL BU DT 391534 - determine if broker is enabled on current database.
_com.CommandText = "select is_broker_enabled from sys.databases where database_id=db_id()";

if (!(bool)_com.ExecuteScalar())
// db_id() returns the database ID of the current database hence it will always be one line result
using SqlDataReader reader = _com.ExecuteReader(CommandBehavior.SingleRow);
if (reader.Read() && reader[0] is not null)
{
dbId = reader.GetBoolean(0);
}
reader.Close();

if (dbId is null || !dbId.Value)
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Can we add test for code that currently throws NRE?

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@Wraith2 Wraith2 Sep 27, 2021 •
edited
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This would be shorter as !dbid.GetValueOrDefault(), I'm not sure if it's clearer and perf isn't a major concern just a general one.

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Regarding the test, it needs more investigation as this only happen on Azure SQL DB and even in this case it may return null.

GetValueOrDefault returns a value even if the HasValue property is false. This also needs more cautious investigation performance wise and also returned value as well.

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GetValueOrDefault returns a value even if the HasValue property is false

Yup, and it does so in a single call with a smaller number of instructions than doing the null check then value check. As long as you have that leading negation it would work. But as I said it's hardly a performance problem so leave it as it already is.

{
throw SQL.SqlDependencyDatabaseBrokerDisabled();
}
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