How do I get different rows in SQL?

How do I get random rows in SQL?

The SQL SELECT RANDOM() function returns the random row. It can be used in online exam to display the random questions. There are a lot of ways to select a random record or row from a database table.

If you want to select a random row with MY SQL:

  1. SELECT column FROM table.
  2. ORDER BY RAND ( )
  3. LIMIT 1.

How do I find the difference between two rows in SQL?

To calculate a difference, you need a pair of records; those two records are “the current record” and “the previous year’s record”. You obtain this record using the LAG() window function. This function allows you to obtain data from the previous record (based on an order criterion, which here is “ ORDER BY year ”).

How do I find unique rows in SQL?

SQL SELECT DISTINCT Explanation

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SELECT DISTINCT returns only unique (i.e. distinct) values. SELECT DISTINCT eliminates duplicate values from the results. DISTINCT can be used with aggregates: COUNT, AVG, MAX, etc. DISTINCT operates on a single column.

How do I retrieve alternate rows in SQL?

How to get the alternate rows or records from table in sql server

  1. ;WITH PRS (Name, Gender, R)
  2. AS.
  3. SELECT NAME, GENDER, ROW_NUMBER() OVER(PARTITION BY GENDER ORDER BY GENDER) AS R.
  4. FROM #PERSON.
  5. SELECT NAME, GENDER FROM PRS ORDER BY R, GENDER DESC.

How can I get first 100 rows in SQL?

The SQL SELECT TOP Clause

  1. SQL Server / MS Access Syntax: SELECT TOP number|percent column_name(s) FROM table_name. …
  2. MySQL Syntax: SELECT column_name(s) FROM table_name. …
  3. Oracle 12 Syntax: SELECT column_name(s) FROM table_name. …
  4. Older Oracle Syntax: SELECT column_name(s) …
  5. Older Oracle Syntax (with ORDER BY): SELECT *

How do I select random 1000 rows in SQL?

How to Return Random Rows Efficiently in SQL Server

  1. select top(20) * from Orders order by newid() …
  2. TABLESAMPLE [SYSTEM] (sample_number [ PERCENT | ROWS ] ) [ REPEATABLE (repeat_seed) ] …
  3. Select * from Orders TABLESAMPLE(20 rows) …
  4. Select top(500) * from Orders TABLESAMPLE(1000 rows)

How do I have multiple rows in one row in SQL?

STUFF Function in SQL Server

  1. Create a database.
  2. Create 2 tables as in the following.
  3. Execute this SQL Query to get the student courseIds separated by a comma. USE StudentCourseDB. SELECT StudentID, CourseIDs=STUFF. ( ( SELECT DISTINCT ‘, ‘ + CAST(CourseID AS VARCHAR(MAX)) FROM StudentCourses t2.

How many tables can be join in SQL query?

Theoretically, there is no upper limit on the number of tables that can be joined using a SELECT statement. (One join condition always combines two tables!) However, the Database Engine has an implementation restriction: the maximum number of tables that can be joined in a SELECT statement is 64.

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How do you find the longest and shortest string in SQL?

“how to find shortest and longest string in sql” Code Answer

  1. # IN the example below, “CITY” is the filed, “STATION” is the Table.
  2. (SELECT CITY, LENGTH(CITY)
  3. FROM STATION.
  4. ORDER BY LENGTH(CITY) ASC, CITY ASC LIMIT 1)
  5. UNION.
  6. (SELECT CITY, LENGTH(CITY)
  7. FROM STATION.
  8. ORDER BY.

How do you eliminate duplicate rows in SQL query without distinct?

Below are alternate solutions :

  1. Remove Duplicates Using Row_Number. WITH CTE (Col1, Col2, Col3, DuplicateCount) AS ( SELECT Col1, Col2, Col3, ROW_NUMBER() OVER(PARTITION BY Col1, Col2, Col3 ORDER BY Col1) AS DuplicateCount FROM MyTable ) SELECT * from CTE Where DuplicateCount = 1.
  2. Remove Duplicates using group By.

How do I select unique rows in mysql?

The go to solution for removing duplicate rows from your result sets is to include the distinct keyword in your select statement. It tells the query engine to remove duplicates to produce a result set in which every row is unique. The group by clause can also be used to remove duplicates.

How do I find duplicate rows in SQL using Rowid?

Use the rowid pseudocolumn. DELETE FROM your_table WHERE rowid not in (SELECT MIN(rowid) FROM your_table GROUP BY column1, column2, column3); Where column1 , column2 , and column3 make up the identifying key for each record. You might list all your columns.

How can get second highest salary in SQL Server?

How To Find Second Highest Salary Using a Sub-Query

  1. SELECT TOP 1 SALARY.
  2. FROM (
  3. SELECT DISTINCT TOP 2 SALARY.
  4. FROM tbl_Employees.
  5. ORDER BY SALARY DESC.
  6. ) RESULT.
  7. ORDER BY SALARY.
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