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1. Top results related to sql query practice

   • SQL Query Practice with ER Diagram

     Top Answer

     Answered Jul 23, 2014 · 2 votes

     Below are queries which will solve your purpose.

     Query for 1

     SELECT prj.proj_num ,asg.emp_num ,avg(asg.assign_hours)FROM Project prjINNER JOIN Assignment asg ON prj.proj_num = asg.proj_numGROUP BY prj.proj_num ,asg.emp_num

     SQL FIDDLE FOR FIRST QUERY

     Query for 2

     SELECT prj.proj_num ,prj.proj_name ,asg.* FROM Project prjINNER JOIN Assignment asg ON prj.proj_num = asg.proj_num WHERE asg.emp_num = 1251 and prj.emp_num <> 1251

     SQL FIDDLE FOR SECOND QUERY

     Assumption made based on your comments - that emp_num column in Project table will have manager emp_num.

     NOTE: TESTED AND WORKS

     Check all answers on Stack Overflow

     1/5

   • SQL Server Query - Best Practice on Where Clause

     Top Answer

     Answered Jul 04, 2014 · 2 votes

     It looks like you should have the NumContrato field as a join condition if they are actually related in all three tables.

     Then in your WHERE clause, where you should be filtering -- not joining -- you can just specify the criteria one time.

     Ie.

     Select b.CodCred, b.Codigo, c.Nome from AS_CredenciadosUsu a inner join AS_Credenciados b on a.CodCred = b.CodCred and a.NumContrato = b.NumContrato inner join Cadastro c on b.Codigo = c.Codigo and c.NumContrato = b.NumContrato Where a.NumContrato = 21 and a.CodUsuD = 1

     Check all answers on Stack Overflow

     2/5

   • SQL - Adding a flag based on results within a query - best practice?

     Top Answer

     Answered Jun 08, 2015 · 0 votes

     CREATE TABLE tbl_user(userId INT NOT NULL AUTO_INCREMENT PRIMARY KEY,lastName VARCHAR(100) NOT NULL);--- drop table tbl_item;CREATE TABLE tbl_item(itemId INT NOT NULL AUTO_INCREMENT PRIMARY KEY,theName VARCHAR(100) NOT NULL,description VARCHAR(255) NOT NULL,category VARCHAR(20) NOT NULL, -- normalize this?cost DECIMAL(10,2) NOT NULL);-- drop table tbljn_userItem;CREATE TABLE tbljn_userItem(userId INT NOT NULL,itemId INT NOT NULL,PRIMARY KEY (userId,itemId) -- in addition maybe a 2nd index going the other way, another covered index-- will leave FK RI to you);INSERT tbl_user(lastName) VALUES ('smith'),('collins'),('jacobs');INSERT tbl_item (theName,description,category,cost) VALUES ('flashlight','a working flashlight','camping',14.95);INSERT tbl_item (theName,description,category,cost) VALUES ('mittens','mittens','winter wear',8.95);INSERT tbl_item (theName,description,category,cost) VALUES ('scarf','red scarf, fuzzy','winter wear',8.95);INSERT tbl_item (theName,description,category,cost) VALUES ('kite','yellow kite','kids',8.95);INSERT tbljn_userItem (userId,itemId) VALUES (3,2),(2,2),(1,2);-- select * from tbl_user;-- select * from tbl_item;-- select * from tbljn_userItem;SELECT i.itemId,i.theName,i.description,i.category,i.cost,( CASE WHEN j.itemId IS NULL THEN 'no' ELSE 'yes' END) AS isOwnedFROM tbl_item iLEFT JOIN tbljn_userItem j ON j.itemId=i.itemId AND j.userId=1LEFT JOIN tbl_user uON u.userId=j.userId AND u.userId=1ORDER BY i.itemIditemId theName description category cost isOwned 1 flashlight a working flashlight camping 14.95 no 2 mittens mittens winter wear 8.95 yes 3 scarf red scarf, fuzzy winter wear 8.95 no 4 kite yellow kite kids 8.95 no

     Check all answers on Stack Overflow

     3/5

   • SQL - Execute SQL query on SQL query

     Top Answer

     Answered Jul 25, 2012 · 6 votes

     Use an inner query i.e.

     SELECT *FROM( YourQueryHere) InnGROUP BY YourColumnHere

     Check all answers on Stack Overflow

     4/5

   • Also try

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     5/5

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2. www.sql-practice.comLearn SQL - Online SQL Terminal - Practice SQL Querys

   www.sql-practice.com

   Practice SQL querys with an online terminal. Solve SQL query questions using a practice database. Learn and improve your SQL skills.

3. www.w3schools.com › SQl › sql_exercisesSQL Exercises - W3Schools

   www.w3schools.com › SQl › sql_exercises

   • Cached

   We have gathered a variety of SQL exercises (with answers) for each SQL Chapter. Try to solve an exercise by filling in the missing parts of a code. If you're stuck, hit the "Show Answer" button to see what you've done wrong.

4. www.geeksforgeeks.org › sql-exercisesSQL Practice with Solution for Beginners and Experienced -...

   www.geeksforgeeks.org › sql-exercises

   • Cached

   Jul 4, 2024 · SQL Exercises for Practice. Practice SQL questions to enhance our skills in database querying and manipulation. Each question covers a different aspect of SQL, providing a comprehensive learning experience. We have covered a wide range of topics in the sections beginner, intermediate and advanced.

5. www.hackerrank.com › domains › sqlSolve SQL | HackerRank

   www.hackerrank.com › domains › sql

   Join over 23 million developers in solving code challenges on HackerRank, one of the best ways to prepare for programming interviews.

6. learnsql.com › blog › sql-query-practiceBasic SQL Query Practice Online: 20 Exercises for Beginners

   learnsql.com › blog › sql-query-practice

   • Cached

   Dec 26, 2023 · These 20 exercises are just what beginners need for SQL query practice. Try to solve each of them, and then look at the solutions. If something needs to be clarified, there are explanations for each solution.

7. learnsql.com › blog › sql-command-practice22 Exercises to Practice SQL Commands | LearnSQL.com

   learnsql.com › blog › sql-command-practice

   • Cached

   Jun 30, 2024 · Practice basic SQL – writing SELECT queries, joining multiple tables, using aggregate functions, and working with GROUP BY – for free with these 18 beginner-friendly exercises. Solutions and explanations included!

8. learnsql.com › blog › sql-interview-questions-guideTop 100+ SQL Interview Questions and Practice Exercises

   learnsql.com › blog › sql-interview-questions-guide

   • Cached

   May 29, 2024 · Practice Regularly. Familiarize Yourself with the Testing Platform. Prepare for Different Types of Questions. Additional Tips. Review Your SQL Knowledge. Explore 55+ General SQL Interview Questions. Practice, Practice, Practice, … SQL Cheat Sheet. Explore 50+ Specific SQL Topic Interview Questions. JOINs. GROUP BY. Data Analysis in SQL.

9. www.codechef.com › practice › sql-case-studies-topic-wiseSQL: 80 Topic wise Practice Queries - CodeChef

   www.codechef.com › practice › sql-case-studies-topic-wise

   Practice queries on Aggregates, Group by, Joins, Sub-queries and Case expressions. Solve over 80 SQL exercises using real life case studies.

10. learnsql.com › blog › sql-practice-questions18 SQL Questions for Beginners: Theory and Practice

    learnsql.com › blog › sql-practice-questions

    • Cached

    Jan 18, 2024 · sql practice. learn sql. Table of Contents. Question 1: Elements of an SQL Query. Question 2: Filtering Data in an SQL Query. Data for Questions 3 – 6. Question 3: Select Cats of a Given Age and Breed. Question 4: List Cats Whose Favorite Toy Is a Ball. Question 5: Find the Most Bored Cat. Question 6: Select Cats that Love Teaser Toys.

11. learnsql.com › blog › sql-practice-for-studentsSQL Practice for Students: 11 Exercises with Solutions

    learnsql.com › blog › sql-practice-for-students

    • Cached

    Nov 9, 2023 · This interactive online course is designed for people who know SQL and are looking for practice exercises that cover single table queries, joins, sorting, grouping, aggregation, and more. It’s part of our SQL Practice track, which contains more SQL practice courses for beginners. Overview of an interactive exercise on LearnSQL.com.