void CreateSubQueries(QueryContextsEntry queryContextsEntry,
OqlExpression expressionTree,
bool hollow,
bool hasSubclassResultsets,
List <QueryOrder> orderings,
int skip,
int take)
{
Type t = queryContextsEntry.Type;
var queryContexts = queryContextsEntry.QueryContexts;
if (queryContexts.Count == 0)
{
this.subQueries.Add(new QueryInfo(t, ConstructQueryString(t, new Dictionary <Relation, Class>(), expressionTree, hollow, hasSubclassResultsets, orderings, skip, take)));
}
else
{
string queryString = string.Empty;
int added = 0;
foreach (var queryContext in queryContexts)
{
if (!queryContext.Any(kvp => kvp.Value.SystemType == t))
{
if (added > 0)
{
queryString += " UNION \r\n";
}
queryString += ConstructQueryString(t, queryContext, expressionTree, hollow, hasSubclassResultsets, orderings, skip, take);
added++;
}
}
this.subQueries.Add(new QueryInfo(t, queryString));
}
}
public string GenerateAggregateQueryString(string field, QueryContextsEntry queryContextsEntry, OqlExpression expressionTree, bool hasSubclassResultsets, AggregateType aggregateType)
{
this.selectPartCreator = CreateAggregateSelectPart;
this.additionalSelectPartData = new Tuple <string, AggregateType>(field, aggregateType);
var query = InnerGenerateQueryString(queryContextsEntry, expressionTree, true, hasSubclassResultsets, new List <QueryOrder>(), 0, 0, null);
return(query);
}
/// <summary>
/// Creates a SQL query string, which can be passed to the IPersistenceHandler to fetch the results for a given concrete type.
/// </summary>
/// <param name="queryContextsEntry">All contexts which define possible mutations of concrete classes in results and relations.</param>
/// <param name="expressionTree">The syntax tree of the NDOql query expression.</param>
/// <param name="hollow">Determines, if the query results should be hollow objects.</param>
/// <param name="hasSubclassResultsets">Determines, if this query is part of a composed query which spans over several tables.</param>
/// <param name="orderings">List of orderings for the resultset.</param>
/// <param name="skip">Determines how many records of the resultset should be skipped. The resultset must be ordered.</param>
/// <param name="take">Determines how many records of the resultset should be returned by the query. The resultset must be ordered.</param>
/// <param name="prefetch">Query for the given prefetch relation.</param>
/// <returns>A Query string.</returns>
public string GenerateQueryString(
QueryContextsEntry queryContextsEntry,
OqlExpression expressionTree,
bool hollow,
bool hasSubclassResultsets,
List <QueryOrder> orderings,
int skip,
int take,
string prefetch)
{
this.selectPartCreator = CreateQuerySelectPart;
return(InnerGenerateQueryString(queryContextsEntry, expressionTree, hollow, hasSubclassResultsets, orderings, skip, take, prefetch));
}
private string InnerGenerateQueryString(QueryContextsEntry queryContextsEntry, OqlExpression expressionTree, bool hollow, bool hasSubclassResultsets, List <QueryOrder> orderings, int skip, int take, string prefetch)
{
CreateSubQueries(queryContextsEntry, expressionTree, hollow, hasSubclassResultsets, orderings, skip, take);
StringBuilder generatedQuery = new StringBuilder();
foreach (QueryInfo qi in subQueries)
{
generatedQuery.Append(qi.QueryString);
generatedQuery.Append(";\n");
}
generatedQuery.Length--; // the trailing \n
if (subQueries.Count == 1)
{
generatedQuery.Length--; // the semicolon
}
return(generatedQuery.ToString());
}
