/// <summary>
/// Compiles eSQL <paramref name="functionDefinition"/> and returns <see cref="DbLambda"/>.
/// Guarantees type match of lambda variables and <paramref name="functionParameters"/>.
/// Passes thru all excepions coming from <see cref="CqlQuery"/>.
/// </summary>
internal static DbLambda CompileFunctionDefinition(
string functionDefinition,
IList<FunctionParameter> functionParameters,
EdmItemCollection edmItemCollection)
{
Debug.Assert(functionParameters != null, "functionParameters != null");
Debug.Assert(edmItemCollection != null, "edmItemCollection != null");
var workspace = new MetadataWorkspace();
workspace.RegisterItemCollection(edmItemCollection);
Perspective perspective = new ModelPerspective(workspace);
// Since we compile lambda expression and generate variables from the function parameter definitions,
// the returned DbLambda will contain variable types that match function parameter types.
var functionBody = CqlQuery.CompileQueryCommandLambda(
functionDefinition,
perspective,
null /* use default parser options */,
null /* parameters */,
functionParameters.Select(pInfo => pInfo.TypeUsage.Variable(pInfo.Name)));
Debug.Assert(functionBody != null, "functionBody != null");
return functionBody;
}
/// <summary>
/// Creates a new instance of perspective class so that query can work
/// ignorant of all spaces
/// </summary>
/// <param name="metadataWorkspace">runtime metadata container</param>
internal TargetPerspective(MetadataWorkspace metadataWorkspace)
: base(metadataWorkspace, TargetPerspective.TargetPerspectiveDataSpace)
{
_modelPerspective = new ModelPerspective(metadataWorkspace);
}
/// <summary>
/// Creates a new instance of perspective class so that query can work
/// ignorant of all spaces
/// </summary>
/// <param name="metadataWorkspace">runtime metadata container</param>
internal TargetPerspective(MetadataWorkspace metadataWorkspace)
: base(metadataWorkspace, TargetPerspective.TargetPerspectiveDataSpace)
{
_modelPerspective = new ModelPerspective(metadataWorkspace);
}
/// <summary>
/// Ensures we have the command tree, either the user passed us the tree, or an eSQL statement that we need to parse
/// </summary>
private void MakeCommandTree()
{
// We must have a connection before we come here
Debug.Assert(_connection != null);
// Do the work only if we don't have a command tree yet
if (_preparedCommandTree == null)
{
DbCommandTree resultTree = null;
if (_commandTreeSetByUser != null)
{
resultTree = _commandTreeSetByUser;
}
else if (CommandType.Text == CommandType)
{
if (!string.IsNullOrEmpty(_esqlCommandText))
{
// The perspective to be used for the query compilation
Perspective perspective = new ModelPerspective(_connection.GetMetadataWorkspace());
// get a dictionary of names and typeusage from entity parameter collection
var queryParams = GetParameterTypeUsage();
resultTree = CqlQuery.Compile(
_esqlCommandText,
perspective,
null /*parser option - use default*/,
queryParams.Select(paramInfo => paramInfo.Value.Parameter(paramInfo.Key))).CommandTree;
}
else
{
// We have no command text, no command tree, so throw an exception
if (_isCommandDefinitionBased)
{
// This command was based on a prepared command definition and has no command text,
// so reprepare is not possible. To create a new command with different parameters
// requires creating a new entity command definition and calling it's CreateCommand method.
throw new InvalidOperationException(Strings.EntityClient_CannotReprepareCommandDefinitionBasedCommand);
}
else
{
throw new InvalidOperationException(Strings.EntityClient_NoCommandText);
}
}
}
else if (CommandType.StoredProcedure == CommandType)
{
// get a dictionary of names and typeusage from entity parameter collection
IEnumerable<KeyValuePair<string, TypeUsage>> queryParams = GetParameterTypeUsage();
var function = DetermineFunctionImport();
resultTree = new DbFunctionCommandTree(Connection.GetMetadataWorkspace(), DataSpace.CSpace, function, null, queryParams);
}
// After everything is good and succeeded, assign the result to our field
_preparedCommandTree = resultTree;
}
}
