How do you delete a statement in SQL?

How do you delete a statement in SQL?


  1. First, you specify the table name where you want to remove data in the DELETE FROM clause.
  2. 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.

What will be the result of omitting the where clause from a delete statement?

If you omit the WHERE clause from a DELETE statement, SQL removes all the rows from the table.

How do you quickly delete a row in SQL?

Removing all the rows fast with truncate. Using create-table-as-select to wipe a large fraction of the data. Dropping or truncating partitions….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.

How do I delete a row in mainframe?

To delete one or more lines:

  1. Type D in the line command field of the line to be deleted. If you also want to delete one or more lines that immediately follow this line, type a number greater than 1 after the D command.
  2. Press Enter. The line or lines are deleted.

What Is syntax for delete the view?

We can delete or drop a View using the DROP statement. Syntax: DROP VIEW view_name; view_name: Name of the View which we want to delete.

What happens when you execute the delete statement?

If you run a DELETE statement with no conditions in the WHERE clause, all of the records from the table will be deleted. This quey will return number of records that will be deleted when you execute the DELETE statement.

Which statement will remove all rows from EMP table using delete?

Truncate statement is use to delete all the rows from table, Ex : TRUNCATE TABLE employee; In Delete statement, we can use where condition.

How do I uninstall run faster?

If you’re deleting a large percentage of the table, say 90+ percent, it may be faster to copy the rows you want to keep to a temp table, truncate the main table, and then reload from the temp table. You don’t provide rowcounts, but a large delete may be faster if done in chunks.

What would be the fastest way to delete all the rows from a 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.

How do I delete a single line?

Is there a shortcut key to delete full line of text?

  1. Place the text cursor at the beginning of the line of text.
  2. On your keyboard, press and hold the left or right Shift key and then press the End key to highlight the entire line.
  3. Press the Delete key to delete the line of text.

How do I delete a record in mainframe?

To delete a record, move the key of the record to the RECORD KEY data item, and then issue the DELETE . Check the file status key after each DELETE statement.

What Is syntax for delete the view delete view View_name drop view View_name Table_name drop view View_name?

SQL VIEW can be created by a SQL query by joining one or more table. If you want to delete a SQL view, It is done by SQL DROP command you should use the following syntax: SQL DROP VIEW syntax: DROP VIEW view_name.

How does a DELETE statement in COBOL work?

The DELETE statement logically removes a record from a mass storage file. After the successful execution of a DELETE statement, the identified record has been logically removed from the file and can no longer be accessed.

What happens when SQLCODE is 0 in COBOL?

IF SQLCODE = 0 DISPLAY ‘Record Inserted Successfully’ DISPLAY WS-STUDENT-REC ELSE DISPLAY ‘Error’ END-IF. STOP RUN. When you compile and execute the above program, it produces the following result −

How to declare studcur cursor in COBOL database?

Cursor declaration can be done in the Working-Storage Section or the Procedure Division. The first statement is the DECLARE statement which is a nonexecutable statement. EXEC SQL DECLARE STUDCUR CURSOR FOR SELECT STUDENT-ID, STUDENT-NAME, STUDENT-ADDRESS FROM STUDENT WHERE STUDENT-ID >:WS-STUDENT-ID END-EXEC.

What do you need to know about COBOL DB2?

COBOL-DB2 applications are those applications that include both COBOL and DB2. Embedded SQL statements work like normal SQL statements with some minor changes. For example, the output of a query is directed to a predefined set of variables which are referred as Host Variables. An additional INTO clause is placed in the SELECT statement.