Lab Sql

I have three tables and want to: Select all students from the first table, that have at least on… Read more I Need An Jpa/sql Expert: Exists Query On An Inner Join Returns Wrong Result

I have query which works. select contract_no AS c_no, cm_mac AS c_mc, MIN(tstamp) as time2, sum(1) … Read more Is It Possible To Optimize Query Using The Exists Instead Of In Clause With Distinct

SELECT * FROM employees e WHERE NOT EXISTS ( SELECT name FROM eo… Read more Shuold I Use Not Exists Or Join Statement To Filter Out Nulls?

I have been looking for a solution to best implement a do not insert if the line already exists. I&… Read more Sql Do Not Insert Duplicates

Suppose I have a query stored in a variable like this (it's actually dynamically populated and … Read more Sql "if Exists..." Dynamic Query

The code I have doesn't work, Oracle tells me the trigger has been created with build errors. A… Read more Using If Exists (select ...) In A Before Insert Trigger (oracle)

let's say that there're 2 tables (in oracle SQL) like this: user(user_id, company_id): 123 … Read more Behavior Of Inner Join Inside Exists Sql

MySql question: What is the difference between [NOT] IN and [NOT] EXIST when doing subqueries in My… Read more Mysql - Difference Between In And Exist

I have two tables, table03 have 10 rows and table01 have 21 rows, now I want to get rows from table… Read more Mysql Select Rows That From Table01 That Doesn't Exist On Table02

I have query which works. select contract_no AS c_no, cm_mac AS c_mc, MIN(tstamp) as time2, sum(1) … Read more Is It Possible To Optimize Query Using The EXISTS Instead Of IN Clause With DISTINCT

I am using the following code to fetch the report. DECLARE @CountryID smallint = 100 DECLARE @UTCTD… Read more SQL Server : Issue In Exists Query Replace With Joins

I have been looking for a solution to best implement a do not insert if the line already exists. I&… Read more SQL Do Not Insert Duplicates