How do I delete all data except one in SQL?

How do I delete all data except one in SQL?

4 Answers

  1. Select the record with id 1800 into a temporary table.
  2. Drop the original table.
  3. Copy the data from the temp table into the full table.

Can we use except in SQL?

The SQL EXCEPT clause/operator is used to combine two SELECT statements and returns rows from the first SELECT statement that are not returned by the second SELECT statement. This means EXCEPT returns only rows, which are not available in the second SELECT statement.

How do I delete a record in SQL?

SQL DELETE Statement

  1. DELETE FROM table_name WHERE condition;
  2. Example. DELETE FROM Customers WHERE CustomerName=’Alfreds Futterkiste’;
  3. DELETE FROM table_name;
  4. Example. DELETE FROM Customers;

How delete all rows except first row in SQL?

DELETE FROM table_name WHERE column_name BETWEEN value 1 AND value 2; Another way to delete multiple rows is to use the IN operator. DELETE FROM table_name WHERE column_name IN (value 1, value 2, value 3, etc…); If you want to delete all records from the table then you can use this syntax.

How does except work in SQL?

The SQL EXCEPT statement is used to filter records based on the intersection of records returned via two SELECT statements. The records that are common between the two tables are filtered from the table on the left side of the SQL EXCEPT statement and the remaining records are returned.

How do I remove duplicates and keep one in SQL?

Linked

  1. 1360.
  2. Delete multiple duplicates leaving max id in sql.
  3. Delete Duplicate Records in table using SQL.
  4. delete rows where id exists more than once but keep the record with the latest date stamp.
  5. Delete All Duplicates Except the MIN StatementID of Each Date.
  6. 528.

Does SQL except remove duplicates?

The EXCEPT ALL operator does not remove duplicates. For purposes of row elimination and duplicate removal, the EXCEPT operator does not distinguish between NULLs. EXCEPT ALL which returns all records from the first table which are not present in the second table, leaving the duplicates as is.

How do I DELETE duplicate records except one in SQL?

If you are using SQL you can manually delete the duplicate rows keeping one entry just follow this procedure:

  1. Go into your table where you have duplicate data.
  2. Apply the filter to segregate duplicate data for each individual id.
  3. Select all the rows you want to delete.
  4. Press delete and save the result.

How do I delete 50% records in SQL?

In SQL Server, DELETE TOP statement is used to delete the records from a table and limit the number of records deleted regarding a fixed value or percentage. Syntax: DELETE TOP (top_value) [ PERCENT ]

What is delete command in SQL?

The DELETE command is used to delete existing records in a table.

How do I delete duplicate records in SQL except one?

Does except remove duplicates?

EXCEPT (alternatively, EXCEPT DISTINCT ) takes only distinct rows while EXCEPT ALL does not remove duplicates from the result rows.

How do I ignore duplicate records in SQL?

Use the INSERT IGNORE command rather than the INSERT command. If a record doesn’t duplicate an existing record, then MySQL inserts it as usual. If the record is a duplicate, then the IGNORE keyword tells MySQL to discard it silently without generating an error.

How do you exclude duplicates in SQL?

SELECT [ALL | DISTINCT] columns FROM table; If a table has a properly defined primary key, SELECT DISTINCT * FROM table; and SELECT * FROM table; return identical results because all rows are unique.

How do I delete duplicate rows but keep one?

How to delete duplicates in Excel but keep one?

  1. Select a cell in your dataset and go to Data > Advanced filter to the far right.
  2. Choose to “Filter the list, in-place” or “Copy to another location”.
  3. Tick the “Unique records only” box to keep the unique values, and then “OK” to remove all duplicates.

How do you delete 10000 records in SQL?

If you need to remove 10 million rows and have 1 GB of log space available use Delete TOP(10000) From dbo. myTable (with your select clause) and keep running it till there are no more rows to delete.

Is truncate faster than delete?

TRUNCATE is faster than DELETE , as it doesn’t scan every record before removing it. TRUNCATE TABLE locks the whole table to remove data from a table; thus, this command also uses less transaction space than DELETE .

How delete a column in SQL?

Right-click the column you want to delete and choose Delete Column from the shortcut menu. If the column participates in a relationship (FOREIGN KEY or PRIMARY KEY), a message prompts you to confirm the deletion of the selected columns and their relationships. Choose Yes.

What is a delete query?

A DELETE query is an action query (SQL statement) that deletes a set of records according to criteria (search conditions) you specify.

How remove duplicate values in SQL 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 remove duplicates in select query?

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.

How do I avoid duplicates in select query?

The SQL DISTINCT keyword, which we have already discussed is used in conjunction with the SELECT statement to eliminate all the duplicate records and by fetching only the unique records.

How do you remove duplicates without using distinct in SQL?

Does select distinct remove duplicates?

Note that the DISTINCT only removes the duplicate rows from the result set. It doesn’t delete duplicate rows in the table. If you want to select two columns and remove duplicates in one column, you should use the GROUP BY clause instead.

How do I remove duplicates from a query?

Remove duplicate rows

  1. To open a query, locate one previously loaded from the Power Query Editor, select a cell in the data, and then select Query > Edit. For more information see Create, load, or edit a query in Excel.
  2. Select a column by clicking the column header.
  3. Select Home > Remove Rows > Remove Duplicates.