How can I delete multiple tables in SQL?

How do I DELETE multiple tables in a single query?

DELETE table1,table2,table3,table4 FROM table1 LEFT JOIN table2 ON table1.pk=table2.pk LEFT JOIN table3 ON table3.pk=table2.pk LEFT JOIN table4 ON table4.pk=table3.pk WHERE table1.pk IN (101,102,106,…)

Can you DELETE from multiple tables at once SQL Server?

You cannot DELETE from multiple tables with a single expression in SQL 2005 – or any other standard SQL for that matter. Access is the exception here. The best method to get this effect is to specify FOREIGN KEYS between the table with an ON DELETE trigger .

How do you bulk DELETE in SQL?

You want a DELETE with a WHERE clause: this is standard SQL. What you can do is batch deletes like this: SELECT ‘Starting’ –sets @@ROWCOUNT WHILE @@ROWCOUNT <> 0 DELETE TOP (xxx) MyTable WHERE …

How do I drop multiple tables at a time?

We can use the following syntax to drop multiple tables: DROP TABLE IF EXISTS B,C,A; This can be placed in the beginning of the script instead of individually dropping each table. Maybe it’s worth pointing out that the tables don’t need to have any relationship at all.

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How do I remove all tables?

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.

How many tables can take in single delete statement?

No, a DML statement can affect only one table.

How do I delete from multiple tables using inner join in SQL Server?

1 Answer

  1. begin transaction;
  2. declare @deletedIds table ( id int );
  3. delete from t1.
  4. output deleted.id into @deletedIds.
  5. from table1 as t1.
  6. inner join table2 as t2.
  7. on t2.id = t1.id.
  8. inner join table3 as t3.

How do I delete a row in a table that contains foreign keys to other tables?

1-You first need to select rows to delete(in a cursor) 2-Then for each row in the cursor you delete the referencing rows and after that delete the row him self.

How do you delete data from two tables using join?

SQL Syntax for delete JOIN

  1. DELETE [target table]
  2. FROM [table1]
  3. INNER JOIN [table2]
  4. ON [table1.[joining column] = [table2].[joining column]
  5. WHERE [condition]

How do I quickly delete in SQL?

Then look at several alternatives you can use in Oracle Database to remove rows faster:

  1. Removing all the rows fast with truncate.
  2. Using create-table-as-select to wipe a large fraction of the data.
  3. Dropping or truncating partitions.
  4. Using a filtered table move.

How do I make SQL delete faster?

Optimizing Delete on SQL Server

  1. be sure foreign keys have indexes.
  2. be sure the where conditions are indexed.
  3. use of WITH ROWLOCK.
  4. destroy unused indexes, delete, rebuild the indexes.
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