internal static extern OdbcReturn SQLGetConnectAttr ( IntPtr ConnectionHandle, OdbcConnectionAttribute Attribute, out int value, int BufferLength, out int StringLength);
internal static extern OdbcReturn SQLSetConnectAttr ( IntPtr ConnectionHandle, OdbcConnectionAttribute Attribute, IntPtr Value, int Length);
internal static extern OdbcReturn SQLGetConnectAttr(
IntPtr ConnectionHandle,
OdbcConnectionAttribute Attribute,
out int value,
int BufferLength,
out int StringLength);
internal static extern OdbcReturn SQLSetConnectAttr(
IntPtr ConnectionHandle,
OdbcConnectionAttribute Attribute,
IntPtr Value,
int Length);
internal static extern OdbcReturnCode SQLSetConnectAttr(OdbcConnectionHandle connectionHandle, OdbcConnectionAttribute attribute, int value, int valueLengthShouldBeZero);
internal static extern OdbcReturnCode SQLSetConnectAttrW(IntPtr connectionHandle, OdbcConnectionAttribute attribute, [In, MarshalAs(UnmanagedType.LPWStr)] string value, int stringLength);
internal static extern OdbcReturnCode SQLGetConnectAttr(IntPtr connectionHandle, OdbcConnectionAttribute attribute, out int value, int valueLengthShouldBeZero, int valueLengthNeededShouldBeZero);
internal static extern OdbcReturnCode SQLGetConnectAttrW(IntPtr connectionHandle, OdbcConnectionAttribute attribute, StringBuilder valueBuffer, int bufferLength, out int bufferLengthNeeded);
internal static void SetStringConnectionAttribute(OdbcConnectionAttribute attribute, string value)
{
if (value == null) throw new ArgumentNullException("value");
var result = NativeMethods.SQLSetConnectAttrW(Constants.IntPtrZero, attribute, value, value.Length * 2);
if ((result != OdbcReturnCode.Success) && (result != OdbcReturnCode.SuccessWithInfo))
{
var ex = new Exception(string.Format("Unable to set ODBC connection attribute '{0:G}'.", attribute));
throw ex;
}
}
internal static void SetIntConnectionAttribute(OdbcConnectionHandle connectionHandle, OdbcConnectionAttribute attribute, int value)
{
if (connectionHandle == null) throw new ArgumentNullException("connectionHandle");
var result = NativeMethods.SQLSetConnectAttr(connectionHandle, attribute, value, 0);
if ((result != OdbcReturnCode.Success) && (result != OdbcReturnCode.SuccessWithInfo))
{
var ex = GetException(connectionHandle, string.Format("Unable to set ODBC connection attribute '{0:G}'.", attribute));
throw ex;
}
}
internal static void SetIntConnectionAttribute(OdbcConnectionAttribute attribute, int value)
{
var result = NativeMethods.SQLSetConnectAttr(Constants.IntPtrZero, attribute, value, 0);
if ((result != OdbcReturnCode.Success) && (result != OdbcReturnCode.SuccessWithInfo))
{
var ex = new Exception(string.Format("Unable to set ODBC connection attribute '{0:G}'.", attribute));
throw ex;
}
}
internal static string GetStringConnectionAttribute(OdbcConnectionAttribute attribute)
{
int bufferLengthNeeded;
var buffer = new StringBuilder(256);
var result = NativeMethods.SQLGetConnectAttrW(Constants.IntPtrZero, attribute, buffer, buffer.Capacity * 2, out bufferLengthNeeded);
if (result == OdbcReturnCode.SuccessWithInfo)
{
var neededCapacity = ((bufferLengthNeeded / 2) + 1);
if (buffer.Capacity < neededCapacity)
{
buffer.Capacity = neededCapacity;
result = NativeMethods.SQLGetConnectAttrW(Constants.IntPtrZero, attribute, buffer, buffer.Capacity * 2, out bufferLengthNeeded);
}
}
if ((result != OdbcReturnCode.Success) && (result != OdbcReturnCode.SuccessWithInfo))
{
var ex = new Exception(string.Format("Unable to get ODBC connection attribute '{0:G}'.", attribute));
throw ex;
}
return buffer.ToString();
}
internal OdbcTransaction(OdbcConnection conn, IsolationLevel isolationlevel)
{
// Set Auto-commit (102) to false
SetAutoCommit(conn, false);
// Handle isolation level
OdbcIsolationLevel lev = OdbcIsolationLevel.ReadCommitted;
OdbcConnectionAttribute attr = OdbcConnectionAttribute.TransactionIsolation;
switch (isolationlevel)
{
case IsolationLevel.ReadUncommitted:
lev = OdbcIsolationLevel.ReadUncommitted;
break;
case IsolationLevel.ReadCommitted:
lev = OdbcIsolationLevel.ReadCommitted;
break;
case IsolationLevel.RepeatableRead:
lev = OdbcIsolationLevel.RepeatableRead;
break;
case IsolationLevel.Serializable:
lev = OdbcIsolationLevel.Serializable;
break;
case IsolationLevel.Snapshot:
// badly broken on MS:
// https://connect.microsoft.com/VisualStudio/feedback/ViewFeedback.aspx?FeedbackID=305736
lev = OdbcIsolationLevel.Snapshot;
// SQL_ATTR_TXN_ISOLATION can be used to set all other isolation
// levels except for SQL_TXN_SS_SNAPSHOT. If you want to use snapshot
// isolation, you must set SQL_TXN_SS_SNAPSHOT through
// SQL_COPT_SS_TXN_ISOLATION. However, you can retrieve the
// isolation level by using either SQL_ATTR_TXN_ISOLATION or
// SQL_COPT_SS_TXN_ISOLATION.
// Source:
// http://msdn2.microsoft.com/en-us/library/ms131709.aspx
attr = OdbcConnectionAttribute.CoptTransactionIsolation;
break;
case IsolationLevel.Unspecified:
// when isolationlevel is not specified, then use
// default isolation level of the driver and
// lazy initialize it in the IsolationLevel property
break;
case IsolationLevel.Chaos:
throw new ArgumentOutOfRangeException("IsolationLevel",
string.Format(CultureInfo.CurrentCulture,
"The IsolationLevel enumeration " +
"value, {0}, is not supported by " +
"the .Net Framework Odbc Data " +
"Provider.", (int)isolationlevel));
default:
throw new ArgumentOutOfRangeException("IsolationLevel",
string.Format(CultureInfo.CurrentCulture,
"The IsolationLevel enumeration value, {0}, is invalid.",
(int)isolationlevel));
}
// only change isolation level if it was explictly set
if (isolationlevel != IsolationLevel.Unspecified)
{
// mbd: Getting the return code of the second call to SQLSetConnectAttr is missing from original code!
OdbcReturn ret = libodbc.SQLSetConnectAttr(conn.hDbc,
attr, (IntPtr)lev, 0);
if (ret != OdbcReturn.Success && ret != OdbcReturn.SuccessWithInfo)
{
throw conn.CreateOdbcException(OdbcHandleType.Dbc, conn.hDbc);
}
}
this.isolationlevel = isolationlevel;
connection = conn;
isOpen = true;
}
