What will happen if we issue a delete SQL statement on a table without a condition?

What will happen if you do not use WHERE condition with DELETE statement?

If you will not provide where clause with delete statement, then whole table data will be deleted. Use this very carefully to avoid any unwanted data loss. … In the syntax above the deletion happens without any condition and will delete all the records of the table.

What will happen if you have this SQL statement DELETE from customer?

Just like the UPDATE statement, the DELETE statement doesn’t technically require a WHERE clause but forgetting the clause can be catastrophic for your data. If you use the DELETE and forget a WHERE clause, SQL identifies the statement as valid and deletes all records in the table.

What happens a DELETE statement is executed for a table?

The SQL delete operation is by far the simplest of all the DML commands. On execution of the delete command, we don’t have to worry about getting any form of data from the table, and we don’t have to worry about working with any data that we get back from the table(s). … Otherwise, it will delete everything in the table.

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Can we use DELETE without WHERE clause?


The WHERE clause specifies which record(s) should be deleted. If you omit the WHERE clause, all records in the table will be deleted!

What is the fastest way to delete data in SQL Server?

Inserting rows in a table is faster than deleting them. Loading data into a new table using create-table-as-select (CTAS) is faster still.

Remove Rows with Create-Table-as-Select

  1. Create a new table saving the rows you want to keep.
  2. Truncate the original table.
  3. Load the saved rows back in with insert as select.

What is delete command in SQL?

In the database structured query language (SQL), the DELETE statement removes one or more records from a table. A subset may be defined for deletion using a condition, otherwise all records are removed.

What is the SQL command to delete a table?

The drop table command is used to delete a table and all rows in the table. To delete an entire table including all of its rows, issue the drop table command followed by the tablename.

Is commit required for delete statement?

The TRUNCATE TABLE statement is a DDL command, so it includes an implicit COMMIT , so there is no way to issue a ROLLBACK if you decide you didn’t want to remove the rows. … SQL for Beginners (Part 10) : The DELETE and TRUNCATE TABLE Statements.

Which SQL query will delete all rows in a table without deleting the table structure?

The TRUNCATE TABLE statement removes all the rows from a table, but the table structure and its columns, constraints, indexes, and so on remain intact. To remove the table definition in addition to its data, you can use the DROP TABLE statement.

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What is the SQL query to delete all rows in a table without deleting the table?

To delete every row in a table:

  1. Use the DELETE statement without specifying a WHERE clause. With segmented table spaces, deleting all rows of a table is very fast. …
  2. Use the TRUNCATE statement. The TRUNCATE statement can provide the following advantages over a DELETE statement: …
  3. Use the DROP TABLE statement.
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