Top "Exists" questions

sqlalchemy exists for query

How do I check whether data in a query exists? For example: users_query = User.query.filter_by(email='x@…

python sqlalchemy exists

C# Cannot check Session exists?

I get an error when I do the following: if(Session["value"] != null) { // code } The error i get is this: …

c# asp.net-mvc session exists

Check if xml node exists in PHP

I have this simplexml result object: object(SimpleXMLElement)#207 (2) { ["@attributes"]=> array(1) { ["version"]=> string(1) "1" } ["weather"]=> object(SimpleXMLElement)#206 (2) { ["@attributes"]=> …

php xml simplexml exists

DELETE records which do not have a match in another table

There are two tables linked by an id: item_tbl (id) link_tbl (item_id) There are some records in …

sql postgresql exists bigdata sql-delete

Correct SQLite syntax - UPDATE SELECT with WHERE EXISTS

I am trying to update a selected values in a column in a SQLite table. I only want update of …

sqlite sql-update where exists

LINQ - Where not exists

What is the equivalent of following statement in LINQ: Select t1.appname, t1.julianDte, t1.cat From table1 t1 Where …

linq exists

SQL Server Set variable if exists else insert into table

I'm looking for a more efficient way of completing this task. I need to set a variable equal to an …

sql-server-2008 stored-procedures exists

Linq To Entities - Any VS First VS Exists

I am using Entity Framework and I need to check if a product with name = "xyz" exists ... I think I …

entity-framework ef-code-first exists any

How to say create procedure if not exists in MySQL

I am trying to create a procedure in a MySQL database, but I want to check if it exists first. …

mysql stored-procedures exists

How to check if list element exists in TCL?

Say I have a TCL list, and I have append some elements to my list. Now I want to check …

list tcl exists