SQL Komutlar

posted in: Web & Comp. | 0

Some of The Most Important SQL Commands

  • SELECT – extracts data from a database
  • UPDATE – updates data in a database
  • DELETE – deletes data from a database
  • INSERT INTO – inserts new data into a database
  • CREATE DATABASE – creates a new database
  • ALTER DATABASE – modifies a database
  • CREATE TABLE – creates a new table
  • ALTER TABLE – modifies a table
  • DROP TABLE – deletes a table
  • CREATE INDEX – creates an index (search key)
  • DROP INDEX – deletes an index

Operators in The WHERE Clause

The following operators can be used in the WHERE clause:

Operator Description
= Equal
<> Not equal. Note: In some versions of SQL this operator may be written as !=
> Greater than
< Less than
>= Greater than or equal
<= Less than or equal
BETWEEN Between an inclusive range
LIKE Search for a pattern
IN To specify multiple possible values for a column


SELECTcolumn_name, column_name
FROM table_name
ORDER BY column_name ASC|DESC, column_name ASC|DESC;


It is possible to write the INSERT INTO statement in two forms.

The first form does not specify the column names where the data will be inserted, only their values:

VALUES (value1,value2,value3,…);

The second form specifies both the column names and the values to be inserted:

INSERTINTOtable_name (column1,column2,column3,…)
VALUES (value1,value2,value3,…);

Leave a Reply

Your email address will not be published. Required fields are marked *

6 + 11 =

This site uses Akismet to reduce spam. Learn how your comment data is processed.