Frequent question: How do I swap in MySQL?

How do I swap values in SQL?

UPDATE TestTable SET Col1 = Col2, Col2 = Col1; When you run above update statement, the values of the columns will be swapped in SQL Server. There is no need for temporary column, variable or storage location in SQL Server. You can validate that with the SELECT statement here.

How do I swap column data in SQL?

How to Swap Values of Two Columns in SQL Server

  1. create table Student.
  2. (
  3. StudentID Int identity primary key,
  4. FirstName varchar(30),
  5. LastName varchar(30),
  6. Marks Int.
  7. )
  8. Insert into Student(FirstName,LastName,Marks) Values(‘Nitin’,’Tyagi’,400)

How do I swap two records in SQL?

A Simple, Scalable Solution

  1. You can do two-row swaps, many-row swaps, and copies. It’s flexible.
  2. Specify as many destination/source row pairs as needed. …
  3. Specify the columns you want to be copied over. …
  4. There’s no temporary table to clean up.
  5. It’s easy to reuse since the row IDs are listed in a single, obvious place.

How can I change table in MySQL?

1 Answer. Use this one command: RENAME TABLE foo TO foo_old, foo_new To foo; It is an atomic operation: both tables are locked together (and for a very short time), so any access occurs either before or after the RENAME .

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How do you create a self join in SQL?

To use a self join, the table must contain a column (call it X) that acts as the primary key and a different column (call it Y) that stores values that can be matched up with the values in Column X. The values of Columns X and Y do not have to be the same for any given row, and the value in Column Y may even be null .

How can I swap two numbers without using third variable in SQL?

Program to swap two numbers without using the third variable

  1. STEP 1: START.
  2. STEP 2: ENTER x, y.
  3. STEP 3: PRINT x, y.
  4. STEP 4: x = x + y.
  5. STEP 5: y= x – y.
  6. STEP 6: x =x – y.
  7. STEP 7: PRINT x, y.
  8. STEP 8: END.

How do I swap columns in Oracle SQL?

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.

How can I change SQL name?

To rename a column in MySQL the following syntax is used: ALTER TABLE table_name RENAME COLUMN old_column_name TO new_column_name; This command is used to change the name of a column to a new column name. However, renaming columns this way you run the risk of breaking database dependencies.

Can distinct command be used for more than one column?

Answer. Yes, the DISTINCT clause can be applied to any valid SELECT query. It is important to note that DISTINCT will filter out all rows that are not unique in terms of all selected columns.

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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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