private HashCodeCombiner GetExpressionHash(Expression expression)
{
var queryContext = _queryContextFactory.Create();
expression = _queryCompiler.ExtractParameters(
expression,
queryContext,
_logger,
parameterize: false);
var hashCode = ExpressionEqualityComparer.Instance.GetHashCode(expression);
var combiner = HashCodeCombiner.Start().Add(hashCode);
var parameterValues = queryContext.ParameterValues;
if (parameterValues.Count > 0)
{
// If query has parameters add to combiner
foreach (var p in parameterValues)
{
combiner.Add(p.Key);
combiner.Add(p.Value);
}
}
return(combiner);
}
/// <summary>
/// parse select statement of queryable
/// </summary>
/// <typeparam name="TEntity"></typeparam>
/// <param name="queryable"></param>
/// <param name="ctx"></param>
/// <returns></returns>
public static SelectParsingResult Parse <TEntity>(this IQueryable <TEntity> queryable, DbContext ctx, bool ignoreQueryFilters) where TEntity : class
{
if (ignoreQueryFilters)
{
queryable = queryable.IgnoreQueryFilters();
}
SelectParsingResult parsingResult = new SelectParsingResult();
Expression query = queryable.Expression;
var databaseDependencies = ctx.GetService <DatabaseDependencies>();
IQueryTranslationPreprocessorFactory _queryTranslationPreprocessorFactory = ctx.GetService <IQueryTranslationPreprocessorFactory>();
IQueryableMethodTranslatingExpressionVisitorFactory _queryableMethodTranslatingExpressionVisitorFactory = ctx.GetService <IQueryableMethodTranslatingExpressionVisitorFactory>();
IQueryTranslationPostprocessorFactory _queryTranslationPostprocessorFactory = ctx.GetService <IQueryTranslationPostprocessorFactory>();
QueryCompilationContext queryCompilationContext = databaseDependencies.QueryCompilationContextFactory.Create(true);
IDiagnosticsLogger <DbLoggerCategory.Query> logger = ctx.GetService <IDiagnosticsLogger <DbLoggerCategory.Query> >();
QueryContext queryContext = ctx.GetService <IQueryContextFactory>().Create();
QueryCompiler queryComipler = ctx.GetService <IQueryCompiler>() as QueryCompiler;
//parameterize determines if it will use "Declare" or not
MethodCallExpression methodCallExpr1 = queryComipler.ExtractParameters(query, queryContext, logger, parameterize: true) as MethodCallExpression;
QueryTranslationPreprocessor queryTranslationPreprocessor = _queryTranslationPreprocessorFactory.Create(queryCompilationContext);
MethodCallExpression methodCallExpr2 = queryTranslationPreprocessor.Process(methodCallExpr1) as MethodCallExpression;
QueryableMethodTranslatingExpressionVisitor queryableMethodTranslatingExpressionVisitor =
_queryableMethodTranslatingExpressionVisitorFactory.Create(queryCompilationContext);
ShapedQueryExpression shapedQueryExpression1 = queryableMethodTranslatingExpressionVisitor.Visit(methodCallExpr2) as ShapedQueryExpression;
QueryTranslationPostprocessor queryTranslationPostprocessor = _queryTranslationPostprocessorFactory.Create(queryCompilationContext);
ShapedQueryExpression shapedQueryExpression2 = queryTranslationPostprocessor.Process(shapedQueryExpression1) as ShapedQueryExpression;
IRelationalParameterBasedSqlProcessorFactory _relationalParameterBasedSqlProcessorFactory =
ctx.GetService <IRelationalParameterBasedSqlProcessorFactory>();
RelationalParameterBasedSqlProcessor _relationalParameterBasedSqlProcessor = _relationalParameterBasedSqlProcessorFactory.Create(true);
SelectExpression selectExpression = (SelectExpression)shapedQueryExpression2.QueryExpression;
selectExpression = _relationalParameterBasedSqlProcessor.Optimize(selectExpression, queryContext.ParameterValues, out bool canCache);
IQuerySqlGeneratorFactory querySqlGeneratorFactory = ctx.GetService <IQuerySqlGeneratorFactory>();
IZackQuerySqlGenerator querySqlGenerator = querySqlGeneratorFactory.Create() as IZackQuerySqlGenerator;
if (querySqlGenerator == null)
{
throw new InvalidOperationException("please add dbContext.UseBatchEF() to OnConfiguring first!");
}
querySqlGenerator.IsForBatchEF = true;
querySqlGenerator.GetCommand(selectExpression);
parsingResult.Parameters = queryContext.ParameterValues;
parsingResult.PredicateSQL = querySqlGenerator.PredicateSQL;
parsingResult.ProjectionSQL = querySqlGenerator.ProjectionSQL;
TableExpression tableExpression = selectExpression.Tables[0] as TableExpression;
parsingResult.TableName = tableExpression.Table.Name;
return(parsingResult);
}
private static (string ExpressionKeyHash, Expression ModifiedExpression) getExpressionKeyHash(
QueryCompiler queryCompiler,
IEFCacheKeyHashProvider cacheKeyHashProvider,
Expression expression)
{
var queryContextFactory = (IQueryContextFactory)_queryContextFactoryField.GetValue(queryCompiler);
var queryContext = queryContextFactory.Create();
var logger = (IDiagnosticsLogger <DbLoggerCategory.Query>)_loggerField.GetValue(queryCompiler);
expression = queryCompiler.ExtractParameters(expression, queryContext, logger, parameterize: false);
var expressionKey = $"{ExpressionEqualityComparer.Instance.GetHashCode(expression)};";
var parameterValues = queryContext.ParameterValues;
if (parameterValues.Any())
{
expressionKey = parameterValues.Aggregate(expressionKey,
(current, item) => current + $"{item.Key}={item.Value?.GetHashCode()};");
}
return(cacheKeyHashProvider.ComputeHash(expressionKey), expression);
}