public string Format(int depth, int indentSize, string fuctionName, MethodCallExpression node)
{
var innerTranslator = new BigQueryTranslateVisitor();
var expr1 = innerTranslator.VisitAndClearBuffer(node.Arguments[0]);
var arg = node.Arguments[1] as NewArrayExpression;
var argMember = node.Arguments[1] as MemberExpression;
string expr2;
if (arg != null)
{
expr2 = string.Join(", ", arg.Expressions.Select(x => innerTranslator.VisitAndClearBuffer(x)));
}
else if (argMember != null)
{
var names = (Array)Expression.Lambda(argMember).Compile().DynamicInvoke();
expr2 = string.Join(", ", names.Cast <object>().Select(x => DataTypeFormatter.Format(x)));
}
else
{
throw new InvalidOperationException();
}
return(string.Format("{0} {1}({2})", expr1, fuctionName, expr2));
}
protected override Expression VisitConstant(ConstantExpression node)
{
var expr = DataTypeFormatter.Format(node.Value);
sb.Append(expr);
return(node);
}
bool FormatIfExprIsDateTime(Expression expr)
{
if (expr is NewExpression)
{
var node = expr as NewExpression;
if (node.Constructor.DeclaringType == typeof(DateTime) || node.Constructor.DeclaringType == typeof(DateTimeOffset))
{
var parameters = node.Arguments.Select(x => ExpressionHelper.GetValue(x)).ToArray();
var datetime = node.Constructor.Invoke(parameters);
var v = DataTypeFormatter.Format(datetime);
sb.Append(v);
return(true);
}
}
if (expr is MemberExpression)
{
var node = expr as MemberExpression;
if (node.Member == now)
{
sb.Append(DataTypeFormatter.Format(DateTime.Now)); return(true);
}
if (node.Member == utcNow)
{
sb.Append(DataTypeFormatter.Format(DateTime.UtcNow)); return(true);
}
if (node.Member == nowOffset)
{
sb.Append(DataTypeFormatter.Format(DateTimeOffset.Now)); return(true);
}
if (node.Member == utcNowOffset)
{
sb.Append(DataTypeFormatter.Format(DateTimeOffset.UtcNow)); return(true);
}
}
return(false);
}
public static FirstWindowFunction <T, TColumn> Lag <T, TColumn>(T fieldSource, string columnName, int offset, TColumn defaultValue)
{
var arg1 = columnName.EscapeBq();
return(new FirstWindowFunction <T, TColumn>("LAG", arg1 + ", " + offset + ", " + DataTypeFormatter.Format(defaultValue)));
}
public static FirstWindowFunction <T, TColumn> Lag <T, TColumn>(T fieldSource, Expression <Func <T, TColumn> > columnSelector, int offset, TColumn defaultValue)
{
var arg1 = BigQueryTranslateVisitor.BuildQuery(0, 0, columnSelector);
return(new FirstWindowFunction <T, TColumn>("LAG", arg1 + ", " + offset + ", " + DataTypeFormatter.Format(defaultValue)));
}
// append field access
protected override Expression VisitMember(MemberExpression node)
{
// WindowFunction, relieve property call and compile.
if (node.Member.GetCustomAttributes <WindowFunctionAttribute>().Any())
{
var methodNode = node.Expression as MethodCallExpression;
MethodCallExpression root;
var paritionBy = (MethodCallExpression)methodNode.Object;
if (paritionBy == null)
{
root = methodNode;
}
else
{
root = (MethodCallExpression)paritionBy.Object;
if (root == null)
{
root = paritionBy;
}
}
var para = root.Arguments[0] as ParameterExpression;
var windowFunction = Expression.Lambda(methodNode, para);
var compiledWindowFunction = windowFunction.Compile();
var windowQuery = compiledWindowFunction.DynamicInvoke(new object[1]);
sb.Append(windowQuery.ToString());
return(node);
}
// specialize for DateTime
if (FormatIfExprIsDateTime(node))
{
return(node);
}
bool isRootIsParameter = false; // as external field or parameter
var nodes = new List <MemberExpression>();
var next = node;
while (next != null)
{
isRootIsParameter = next.Expression.NodeType == ExpressionType.Parameter;
nodes.Add(next);
var nextExpr = next.Expression;
next = nextExpr as MemberExpression;
if (next == null)
{
// skip indexer access for repeated field
var binaryNext = nextExpr;
while (binaryNext is BinaryExpression)
{
binaryNext = ((BinaryExpression)binaryNext).Left;
if (binaryNext is MemberExpression)
{
next = (MemberExpression)binaryNext;
break;
}
}
}
}
if (isRootIsParameter)
{
sb.Append("[");
for (int i = nodes.Count - 1; i >= 0; i--)
{
sb.Append(nodes[i].Member.Name);
// If Nullable don't emit .Value
if (nodes[i].Type.IsNullable())
{
break;
}
if (nodes.Count != 1 && i != 0)
{
sb.Append(".");
}
}
sb.Append("]");
}
else
{
var v = ExpressionHelper.GetValue(nodes[0]);
var str = DataTypeFormatter.Format(v);
sb.Append(str);
}
return(node);
}
