private DbCommand CreateCommand(DbProviderManifest manifest, DbCommandTree commandTree)
{
if (manifest == null)
{
throw new ArgumentNullException("manifest");
}
if (commandTree == null)
{
throw new ArgumentNullException("commandTree");
}
var expectedTypes = PrepareTypeCoercions(commandTree);
FbCommand command = FbCommand.CreateWithTypeCoercions(expectedTypes);
List <DbParameter> parameters;
CommandType commandType;
command.CommandText = SqlGenerator.GenerateSql(commandTree, out parameters, out commandType);
command.CommandType = commandType;
// Get the function (if any) implemented by the command tree since this influences our interpretation of parameters
EdmFunction function = null;
if (commandTree is DbFunctionCommandTree)
{
function = ((DbFunctionCommandTree)commandTree).EdmFunction;
}
// Now make sure we populate the command's parameters from the CQT's parameters:
foreach (KeyValuePair <string, TypeUsage> queryParameter in commandTree.Parameters)
{
FbParameter parameter;
// Use the corresponding function parameter TypeUsage where available (currently, the SSDL facets and
// type trump user-defined facets and type in the EntityCommand).
FunctionParameter functionParameter;
if (null != function && function.Parameters.TryGetValue(queryParameter.Key, false, out functionParameter))
{
parameter = CreateSqlParameter(functionParameter.Name, functionParameter.TypeUsage, functionParameter.Mode, DBNull.Value);
}
else
{
parameter = CreateSqlParameter(queryParameter.Key, queryParameter.Value, ParameterMode.In, DBNull.Value);
}
command.Parameters.Add(parameter);
}
// Now add parameters added as part of SQL gen (note: this feature is only safe for DML SQL gen which
// does not support user parameters, where there is no risk of name collision)
if (null != parameters && 0 < parameters.Count)
{
if (!(commandTree is DbInsertCommandTree) &&
!(commandTree is DbUpdateCommandTree) &&
!(commandTree is DbDeleteCommandTree))
{
throw new InvalidOperationException("SqlGenParametersNotPermitted");
}
foreach (DbParameter parameter in parameters)
{
command.Parameters.Add(parameter);
}
}
return(command);
}