Top "Exists" questions

sql: check if entry in table A exists in table B

I have a definition table that I know is not being maintained very well, lets call this table A. I …

sql exists

How to use SQL Select statement with IF EXISTS sub query?

How to select Boolean value from sub query with IF EXISTS statement (SQL Server)? It should be something like : SELECT …

sql sql-server exists

How to Check if value exists in a MySQL database

Suppose I have this table: id | name | city ------------------ 1 | n1 | c1 2 | n2 | c2 3 | n3 | c3 4 | n4 | c4 I want to …

php mysql exists

Select rows which are not present in other table

I've got two postgresql tables: table name column names ----------- ------------------------ login_log ip | etc. ip_location ip | location | hostname | …

sql postgresql null left-join exists

How to exclude records with certain values in sql select

How do I only select the stores that don't have client 5? StoreId ClientId ------- --------- 1 4 1 5 2 5 2 6 2 7 3 8 I'm trying something like this: …

sql sql-server tsql exists

SQL - IF EXISTS UPDATE ELSE INSERT INTO

What I'm trying to do is INSERT subscribers in my database, but IF EXISTS it should UPDATE the row, ELSE …

mysql sql insert exists

IF EXISTS in T-SQL

If we have a SELECT statement inside an IF EXISTS, does the execution stop as soon as it finds a …

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Best way to check if object exists in Entity Framework?

What is the best way to check if an object exists in the database from a performance point of view? …

entity-framework linq-to-entities exists

Check if MySQL table exists or not

Possible Duplicate: MySQL check if a table exists without throwing an exception I have a dynamic mysql query builder in …

php mysql exists

SQL Server IN vs. EXISTS Performance

I'm curious which of the following below would be more efficient? I've always been a bit cautious about using IN …

sql-server sql-server-2005 exists query-performance sql-in