Frequent question: How do I swap rows in SQL?

How do you swap rows in SQL?

2 Answers

  1. select Id,
  2. case when row_number() over (order by Id) % 2 = 1.
  3. then lead(name) over (order by Id)
  4. else lag(name) over (order by Id) end as name.
  5. from MyTable.

How do I swap values in SQL?

How to Swap Column Values in SQL

  1. create table coordinates ( x integer, y integer ); insert into coordinates (x, y) values (5, 12); select * from coordinates;
  2. update coordinates set x = y, y = x; select * from coordinates;
  3. update coordinates set x = (@temp := x), x = y, y = @temp;

How do you interchange rows and columns in SQL?

Option #4: Dynamic SQL

  1. DECLARE @columns NVARCHAR(MAX), @sql NVARCHAR(MAX);
  2. SET @columns = N”;
  3. SELECT @columns+=N’, p.’ +QUOTENAME([Name])
  4. SELECT [DocName] AS [Name]
  5. FROM [dbo].[ InsuranceClaims] AS p.
  6. GROUP BY [DocName]
  7. ) AS x;
  8. SET @sql = N’

How do I swap rows in MySQL?

Swapping two column values in MySQL?

  1. Add both values and store them into the first column.
  2. Subtract the first column’s value from the second and store it into the second column.
  3. Subtract the first column’s value from the updated second column and store it into the first.
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How do I swap columns in SQL Server?

To change the column order

  1. In Object Explorer, right-click the table with columns you want to reorder and click Design.
  2. Select the box to the left of the column name that you want to reorder.
  3. Drag the column to another location within the table.

How do you do if else in SQL?

Any T-SQL statement can be executed conditionally using IF… ELSE. If the condition evaluates to True, then T-SQL statements followed by IF condition in SQL server will be executed. If the condition evaluates to False, then T-SQL statements followed by ELSE keyword will be executed.

How can I swap two values in the same column in Oracle?

Interchange the Values of 2 Columns

  1. Alter table employee and add a new column TEMP_NAME to it.
  2. Update the values of LAST_NAME to TEMP_NAME.
  3. Update the LAST_NAME with the values of FIRST_NAME.
  4. Update the FIRST_NAME with the values of TEMP_NAME.
  5. Drop the column TEMP_NAME.

What is trigger in SQL?

A SQL trigger is a database object which fires when an event occurs in a database. We can execute a SQL query that will “do something” in a database when a change occurs on a database table such as a record is inserted or updated or deleted. For example, a trigger can be set on a record insert in a database table.

What is decode function in SQL?

What is DECODE function in SQL? In Oracle, DECODE function allows us to add procedural if-then-else logic to the query. DECODE compares the expression to each search value one by one. If expression is equal to a search, then the corresponding result is returned by the Oracle Database.

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How do I convert rows to columns in SQL?

In SQL Server you can use the PIVOT function to transform the data from rows to columns: select Firstname, Amount, PostalCode, LastName, AccountNumber from ( select value, columnname from yourtable ) d pivot ( max(value) for columnname in (Firstname, Amount, PostalCode, LastName, AccountNumber) ) piv; See Demo.

How do I use multiple rows 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 do I convert columns to rows in SQL?

Let’s Start!

  1. UNION ALL. Previously, SQL Server did not offer an efficient way to convert columns into rows. …
  2. UNPIVOT. One of the fastest ways to convert columns into rows is definitely to use the UNPIVOT operator, which was introduced in SQL Server in 2005. …
  3. VALUES. …
  4. Dynamic SQL. …
  5. XML.

How do I switch columns in mysql?

phpMyAdmin provides a GUI for this within the structure view of a table. Check to select the column you want to move and click the change action at the bottom of the column list. You can then change all of the column properties and you’ll find the ‘move column’ function at the far right of the screen.