Lab Sql

This is my table tblEmployee ,when I'm trying to use a self join query it's result is varyi… Read more Not Quite Understanding The Query After Just Shifting Column Names

I have the following tables that I need to run query against each. userA id name … Read more Query Based On Common Criteria From Two Tables And Sort Based On Number Of Occurrences

If I run the following SQL query SELECT * FROM A LEFT JOIN B ON A.foo=B.foo WHERE A.date = 'Ye… Read more Sql Order Of Operations

SELECT DISTINCT a.*, b.* FROM current_tbl a LEFT JOIN import_tbl b … Read more Sql: Speed Improvement - Left Join On Cond1 Or Cond2

I have this query: SELECT p.id, r.status, r.title FROM page AS p INNER JOIN page_revision as r … Read more Sql Query Performance Question (multiple Sub-queries)

I am not able to understand how Cartesian product works. Consider the simple schema: mysql> sele… Read more Understanding Cartesian Product In Sql

I have this database: And I need to get the following data for each Client: Client Name Contract… Read more Sql Server Equivalent To Group_concat()

i have a select command in my query that fetch data from two table , and each row of result come t… Read more Joining Two Table And Result Come Twice In Result