¿Cómo elimino un valor específico en una columna en Oracle?

How do I delete a specific value in a column in Oracle?

Physical Delete To physically drop a column you can use one of the following syntaxes, depending on whether you wish to drop a single or multiple columns. alter table table_name drop column column_name; alter table table_name drop (column_name1, column_name2);

In Object Explorer, locate the table from which you want to delete columns, and expand to expose the column names. Right-click the column that you want to delete, and choose Delete. In Delete Object dialog box, click OK.

First, you specify the table name where you want to remove data in the DELETE FROM clause. Second, you put a condition in the WHERE clause to specify which rows to remove. If you omit the WHERE clause, the statement will remove all rows in 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.

In this statement,

1. First, you specify the name of the table from which you want to delete data.
2. Second, you specify which row should be deleted by using the condition in the WHERE clause. If you omit the WHERE clause, the Oracle DELETE statement removes all rows from the table.

We can use Alter table command to remove a column as well.

Summary: in this tutorial, you will learn how to use the Oracle TRUNCATE TABLE statement to delete all data from a table faster and more efficiently. When you want to delete all data from a table, you use the DELETE statement without the WHERE clause as follows: For a table with a small number of rows, the DELETE statement does a good job.

See these important notes on tuning Oracle DELETE statements for faster performance. Online table redefinition: You can drop large numbers of rows from a table by adding a WHERE clause predicate to filter-out unwanted rows when you copy the table.

DELETE. The DELETE statement removes entire rows of data from a specified table or view. If you want to “remove” data from particular column update it: UPDATE table_name SET your_column_name = NULL; or if column is NOT NULL. UPDATE table_name SET your_column_name = ; You can also remove entire column using DDL:

Code language: SQL (Structured Query Language) (sql) In this statement, First, you specify the name of the table from which you want to delete data. Second, you specify which row should be deleted by using the condition in the WHERE clause. If you omit the WHERE clause, the Oracle DELETE statement removes all rows from the table.