Other Functions

Find definitions for other functions from bit_count to version.

Function Description
bit_count Returns the number of bits that are set in the argument N.
charset Returns the character set of the string argument.
coercibility Returns the collation coercibility value of the string argument.
collation Returns the collation of the string argument.
compress Compresses a string and returns the result as a binary string. This function requires MySQL to have been compiled with a compression library such as zlib. Otherwise, the return value is always NULL. The compressed string can be uncompressed with UNCOMPRESS().
decode Decrypts the encrypted string crypt_str using pass_str as the password. crypt_str should be a string returned from ENCODE().
des_crypt Decrypts a string encrypted with DES_ENCRYPT(). If an error occurs, this function returns NULL.
des_enctrypt Encrypts the string with the given key using the Triple-DES algorithm.
encoder Encrypts str using pass_str as the password. To decrypt the result, use DECODE().
encrypt Encrypts str using the Unix crypt() system call and returns a binary string. The salt argument should be a string with at least two characters. If no salt argument is given, a random value is used.
md5 Calculates an MD5 128-bit checksum for the string. The value is returned as a binary string of 32 hex digits, or NULL if the argument was NULL. The return value can, for example, be used as a hash key.
sha1 Calculates an SHA-1 160-bit checksum for the string, as described in RFC 3174 (Secure Hash Algorithm). The value is returned as a binary string of 40 hex digits, or NULL if the argument was NULL. One of the possible uses for this function is as a hash key. You can also use it as a cryptographic function for storing passwords. SHA() is synonymous with SHA1().
uncompress Uncompresses a string compressed by the COMPRESS() function. If the argument is not a compressed value, the result is NULL. This function requires MySQL to have been compiled with a compression library such as zlib. Otherwise, the return value is always NULL
uncompressed Returns the length that the compressed string had before being compressed.
version A SELECT statement may include a LIMIT clause to restrict the number of rows the server returns to the client. In some cases, it is desirable to know how many rows the statement would have returned without the LIMIT, but without running the statement again. To obtain this row count, include a SQL_CALC_FOUND_ROWS option in the SELECT statement, and then invoke FOUND_ROWS() afterward: